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1  Alvarez-J; Snyder-G-H; Jones-D-B  The integrated program approach in the development of the Florida (USA) rice industry.  JOURNAL OF AGRONOMIC EDUCATION (1989) 18 (1): 6-11, [En] Everglades Res. and Educ. Cent., Univ. Fla., P.O. Box 8003, Belle Glade, Fla. 33430-8003

Integrated programs have become one of the means used to deal with declining farm profitability in the United States. The introduction and establishment of the Florida rice industry is a case in point. Low sugar prices and land idled during the summer months gave birth the industry when one sugar cane (Saccharum spp.) producer planted 114 ha of rice (Oryza sativa L.) in rotation with sugar cane in 1977. Problems solved during the first years included the lack of rice combines, developing cultural techniques for organic soils, lack of drying and milling facilities, seedling chlorosis, and market development. Solving these problems allowed the industry to reach a relatively mature and stable stage: 5844 ha were planted in 1988; grain yields have increased from the early 3360 kg ha-1 to about 5600 kg ha-1; commercial drying and milling facilities have been expanded; and a research and extension team is working closely with the growers. The results from this integrated program should be of importance to those searching for new alternatives or working in the area of sustainable agriculture. This case study shows that integrated programming does not always need prior planning and structuring, since it can evolve with time and changing needs. Finally, grower participation can be of utmost importance in the fulfillment of the program objectives.

2  Palm-O; Sandell-K  Sustainable agriculture and nitrogen supply in Sri Lanka: Farmer's and scientists' perspective.  AMBIO (1989) 18 (8): 442-448 [En, Ref. 8] National Environment Protection Agency, Box 1302, S-171 25 Solna, Sweden

The sustainability of agricultural development has long been neglected due to short-term perspectives and the striking productivity of the green revolution. This is the case even concerning the supply of nutrients. Heavy usage of chemical fertilizers involves large amounts of nonrenewable energy resources of production, as well as for the operation of distribution systems. These aspects have been studied with an interdisciplinary approach involving the documentation of practices and perspectives of local farmers. Special emphasis has been placed on paddy-rice cultivation carried out in five villages with low-resource agriculture in the Dry Zone of Sri Lanka.

3  Liebman-M  Effects of nitrogen fertilizer, irrigation, and crop genotype on canopy relations and yields of an intercrop/weed mixture.  FIELD CROPS RESEARCH (1989) 22 (2): 83-100 [En, Ref. 2] Sustainable Agriculture Prog., Univ. Maine, Orono, Maine, 04469

Two field experiments were conducted to investigate effects of soil conditions and crop genotypes on canopy relations and yield responses of two crops (barley and field pea) and a weed (white mustard) sown in trispecific mixtures. Treatments involved variations in nitrogen supply, water supply and pea genotype. Photosynthetic surface area and seed yield of pea were increased by increasing water supply, but were unaffected or diminished by increasing nitrogen supply. 'Century' pea produced about four times more surface area than 'Alaska' pea. Under irrigated, low-nitrogen conditions, seed yields of the two pea varieties were similar, but under high-nitrogen conditions, seed yield of the smaller variety declined significantly. Under high-nitrogen conditions, the larger 'Century' pea constituted a large proportion of the upper levels of the mixed-species canopies, while the smaller 'Alaska' pea was overtopped and shaded by mustard. Increasing nitrogen or water supply increased photosynthetic surface area of barley, but most of these increases occurred at canopy levels where only small amounts of photosynthetically active radiation (PAR; or Q-pa) were available. Increasing nitrogen supply had a much stronger positive effect on barley seed yield than did increasing water supply. Use of 'Century' pea rather than the smaller 'Alaska' pea decreased barley's photosynthetic surface area, access to Q-pa, and seed yield. In terms of canopy development, Q-pa interception, and yield, nitrogen fertilizer benefitted mustard much more than it did either crop species. Averaged across irrigation regimes, pea genotypes, and years, application of N increased mustard biomass by 472%, but increased total crop seed yield only 31%. Increasing water supply had much less effect than nitrogen fertilizer on mustard's production of photosynthetic surface area and biomass. Use of 'Century' pea rather than the smaller 'Alaska' pea resulted in increased shading and decreased growth of mustard. Results of the experiments indicate that soil conditions, the relative values and desired yields of the different component crops, and the degree of priority placed on weed suppression should all bear on the choice of appropriate crop varieties for intercropping systems. When the smaller 'Alaska' pea was used in the intercrop/weed mixtures, a large total amount of crop seed (pea + barley) was produced under high-water, low-nitrogen conditions. Total crop seed yield was greatest, however, when the larger 'Century' pea was used in the the mixtures and nitrogen fertilizer was applied. 

4  Clay-D-C; Lewis-L-A  Land use, soil loss, and sustainable agriculture in Rwanda. HUMAN ECOLOGY (1990) 18 (2): 147-162 [En, Ref. 12]  Michigan State University, Dep. Sociology, Berkey Hall, East Lansing, Mich. 48824 

The conservation of scarce land resources is essential to the long-term viability of agriculture in Rwanda. High population density, steep slopes, and abundant rainfall prevail in the highland portions of this African country, making the task of erosion control uncommonly difficult for the peasant farmer. The specific use to which land is put, e.g., cultivation, fallow, pasture, woodlots, and, if it is cultivated, the particular combination of crops grown, can be seen as contributing to both the cause and the solution of the land degradation problem. Based on data from a nationwide survey of over 4800 agricultural fields in Rwanda, this study reviews the extent to which the land use and cropping patterns employed by farmers are appropriately suited, in terms of erosion control, to the topographical and environmental characteristics of their landholdings. Analyses of other aspects of the traditional agricultural system, e.g., variations in relative soil fertility, the use of organic fertilizers, and the location of fields relative to the household, are introduced to help explain why farmers often fail to maximize erosion control through land use and cropping practices. Adjustments to current land use practices that can be expected to reduce soil loss are discussed.

5           Banuelos-G-S; Meek-D-W  Accumulation of selenium in plants grown on selenium-treated soil.  JOURNAL OF ENVIRONMENTAL QUALITY (1990) 19 (4): 772-777, [En, Ref. 4] USDA-ARS, Pacific West Area, 2021 S. Peach Ave., Fresno, Calif. 93727.

High concentrations of Se found in the environment may be deterimental to sustainable agriculture in parts of the western USA. Greenhouse pot experiments were conducted to study Se concentrations in different plant species grown in soil with added Se. Astragalus incanus L. (no common name), creeping saltbush (Atriplex semibaccata R. Br. L.), Old Man saltbush (Atriplex nummularia Lindl L.), wild brown mustard (Brassica juncea Czern L.), and tall fescue grass (Festuca arundinacea Schreb L.) were grown in potting soil to which 3.5 mg Se-6+ or Se-4+ kg-1 was added either as Na-2SeO₄ or Na-2SeO₃, respectively. During the growing season, plants from both Se-treated soils were clipped either once, twice, or three times. After 50 to 55 d in Se-treated soil, plants were harvested, separated into shoots and roots, and analyzed for total tissue Se. Soils from each species were analyzed for total residual Se. Each species grown in Se-6+-treated soils, accumulated significantly (P lt 0.001) more Se than plants grown in Se-4+-treated soil. For both Se-6+ and Se-4+ treatments, wild brown mustard and A. incanus had the highest and lowest tissue Se concentrations, respectively. Clipping of plants significantly (P lt 0.05) increased the accumulation of Se in the total harvested shoot tissue for wild brown mustard and slightly for the other species tested (except Old Man saltbush). Reduction in soil Se was observed for each species, with the greatest reduction occurring when plants of wild brown mustard were grown and clipped. Within any given treatment, wild brown mustard accumulated the highest concentrations of Se. In the remaining species, Se accumulated in the following order: Old Man saltbush gt creeping saltbush gt tall fescue gt A. incanus. Selenium removal from soil by each species generally followed the same order as the accumulation of Se in the plant.

6  Geng-S; Hess-C-E; Auburn-J  Sustainable agricultural systems: Concepts and definitions. JOURNAL OF AGRONOMY AND CROP SCIENCE (1990), 165 (2-3): 73-85,  [En, Ref. 1] Dep. Agronomy Range Science, College Agric. Environmental Sciences, University California, Davis, Calif. 95616

The evolution of concepts and definitions of agricultural systems over time is presented. Inputs of an agricultural system are classified as components and activities. A component is either a resource or a technology. The activities are the management of resources and the application of technology in the production process. The outputs of a production process will include both the targeted product and the environmental impact. When these terms are used to describe an agricultural system graphically, the dynamic aspects of the system can easily be illustrated and problems associated with the system can be properly identified. Sustainable agriculture is recognized as conveying certain objectives or delineating certain requirements of an agricultural system, in terms of both the input and output of the system. These objectives are: (1) producing necessary quantity of high quality food and fiber; (2) profitable to the grower; (3) conserving nonrenewable resources; and (4) harmonious with biological, physical and social environments. These objectives have long-term implications and attempt to secure the future viability of agriculture. Therefore they embrace the concept of sustainability. The difficulty of constructing such a system is that not all the objectives are compatible; compromise or trade-offs among the objectives are often necessary in developing a workable sustainable system. Progress and improvement can always be made through research, but no perfect system can realistically be constructed. General research issues in sustainable agriculture are discussed. Priorities in developing appropriate technology based on sound biological principles and laws of physics and mechanics for pest and weed control are suggested.

7  Krall-J-M; Delaney-R-H; Taylor-D-T  Survey of nonirrigated crop production practices and attitudes of Wyoming producers.  JOURNAL OF AGRONOMIC EDUCATION (1991) 20 (2): 120-122, [En, Ref. 10] Dep. Plant Soils Insect Sci., Univ. Wyo., Laramie, Wyo. 82071

Sustainable-agriculture research and educational efforts are increasing, but an assessment of current production practices and producer attitudes is important before undertaking such activities. To assess nonirrigated production systems in Wyoming, questionnaires were sent to 513 commercial producers. Two hundred twenty-five surveys were completed and returned. While the majority of producers (76%) retain the traditional winter wheat (Triticum aestivum L.)/fallow system, many are experimenting with rotations. Twenty-nine different rotations were reported. Legume use in rotations was low (5%) and represents a research opportunity. Producers are experimenting with fallow practices. Over the previous 5 yr, 44% had attempted an alternative practice, with most producers placing environmental concerns ahead of input-cost considerations when selecting fallow practices. Twenty producers, 9% of the respondents, did not pesticides or commercial fertilizer. Seventy-four percent were very or somewhat interested in attending a meeting on low-input practices. Results indicate there are research and educational opportunities in nonirrigated production practices for the University of Wyoming.

8  Castro-Filho-C; Henklain-J-C; Vieira-M-J; Casao-R-JR  Tillage methods and soil and water conservation in southern Brazil. SOIL & TILLAGE RESEARCH  (1991) 20 (2-4): 271-284, [En, Ref. 5] Inst. Agron. Parana, P.O. Box 1331, Londrina, PR, Brazil

The intensive tillage systems adopted in southern Brazil have accelerated soil erosion, depleted plant-available nutrients and reduced crop productivity. These effects are better perceived in terms of farmer's land use and soil management techniques, i.e. animal- or machine-powered equipment through high and low aptitude and land use classification systems. However, these tillage systems coexist together at the level of agricultural watersheds and are not compatible for continuous and sustainable agriculture. This article proposes a methodology for using agricultural watersheds as planning units for integrated soil conservation plans. This methodology is based on considerations of the farmer's socioeconomic conditions, land aptitude and other biophysical factors. The proposed methodology envisages a continuous and intensive land use for sustained production.

10     Sriskandarajah-N; Dignam-D  The quest for sustainable agriculture: The current position in Australia. AGRICULTURE ECOSYSTEMS & ENVIRONMENT (1992) 39 (1-2): 85-100, [En, Ref. 12] Fac. Agric. Rural Dev., Univ. Western Sydney, Hawkesbury, Richmond, N.S.W. 2753, Aust

The primary production sector has contributed significantly to the growth of the Australian economy over the 200 years of European settlement. The farming systems that have developed utilize large areas of land, little labour and produce commodities for export, with pastoral farming systems accounting for more than half of all land farmed. Productivity increases were accompanied by a decline in the quality of the environment, particularly land degradation through non-sustainable farming practice. Several programs directed at sustainable resource management have been installed by the government. Organic farming is increasing rapidly and, at present, the demand for organic produce exceeds the supply. While farming techniques for sustainable systems have been developed through research, the adoption of such techniques by farmers has been slow. Community participation through landcare and catchment management groups in collaborative research and extension activities is being promoted throughout the country. Attitudes towards the land and awareness of environmental issues are changing in rural and urban communities. Innovative approaches are required to facilitate the learning needs of the people and to promote co-operation between landholders, researchers and extension workers. Systemic action research is an alternative paradigm for working with people towards a more sustainable agriculture in Australia.

11       Altieri-M-A Agroecological foundations of alternative agriculture in California. AGRICULTURE ECOSYSTEMS & ENVIRONMENT (1992) 39 (1-2): 23-5, [En, Ref. 12] Div. Biol. Control, Univ. Calif.-Berkeley, 1050 San Pablo Ave., Albany, Calif. 94706, USA

Most agricultural regions of California (USA) enjoy long growing seasons, fertile soils and irrigation, all conditions that favor a highly diversified cropping. In addition, the wide variety of vegetables, field and tree crops determine a high deversity and flexibility of agricultural enterprises. Despite these factors, Californian agroecosystems are dominated by monocultural cropping systems. Although productive, these system lack the ecological features to ensure efficient nutrient cycling, water and soil conservation, and biotic regulation. Productivity is subsidized with chemical inputs such as pesticides and fertilizers, some of which cause undesirable environmental and public health hazards. Large-scale monocultures are also highly susceptible to wind erosion and are dependent on ground water for irrigation, leading in some areas to a considerable 'overdraft'. In other regions, poor field drainage and rising water tables are leading to unacceptable soil salinity levels. In summary, California agriculture is very productive, but the environmental cost of such productivity is threatening the sustainability of agriculture. The search for self-sustaining, low-input, diversified and energy-efficient agricultural systems is now a major concern of researchers, farmers, policy makers and the public in California. The long tradition in biological pest control in California, as well as the experience of a number of organic farmers who developed low-input systems through 'trial' and error', provide the building blocks for the search for a more sustainable agriculture. A key strategy in sustainable agriculture is to restore the agricultural diversity of the agricultural landscape. Diversity can be enhanced in time through crop rotations and sequences, and in space in the form of cover crops, intercropping, agroforestry crop/livestock mixtures, etc. Vegetation diversification not only results in pest regulation through restoration of natural controls, but also produces optimal nutrient recycling, energy conservation and less dependence on cultural inputs. In California, although this new approach to agriculture is actively researched, realistically it will work only if it is economically sensible and can be carried out within the constraints of a fairly normal agricultural system. Therefore, adoption of recommended diversification designs will proceed as these reduce costs and increase the efficiency and viability of farmers.

12       Altieri-M-A  Sustainable agricultural development in Latin America: Exploring the possibilities. AGRICULTURE ECOSYSTEMS & ENVIRONMENT (1992) 39 (1-2): 1-21, [En, Ref. 12] Div. Biol. Control, Univ. Calif.-Berkeley, 1050 San Pablo Ave., Albany, Calif. 94706, USA

This paper concentrates on what are perceived as critical issues which should be addressed if a productive and sustainable agriculture is to be achieved in Latin America. The attainment of such an agriculture is dependent on new technological innovations, policy changes and more socio-equitable economic schemes. By using several examples of biological control and integrated pest management programs (for insects) as case studies, ways of promoting the transition of chemical intensive commercial agriculture to low-input management are explored. Similarly, the paper describes non-governmental efforts utilizing the agroecological approach to help the great mass of resource-poor farmers, mostly confined to marginal soils, hillsides and rainfed areas, to achieve year-round food self-sufficiency, reduce their reliance on scarce and expensive agricultural chemical inputs, and develop production systems that rebuild the productive capacities of their smallholdings.

13       Ceccarelli-S; Valkoun-J; Erskine-W; Weigand-S; Miller-R; Van-Leur-J-A-G  Plant genetic resources and plant improvement as tools to develop sustainable agriculture.  EXPERIMENTAL AGRICULTURE (1992) 28 (1): 89-98, [En, Ref. 9] Int. Cent. Agric. Res. Dry Areas, P.O. Box 5466, Aleppo, Syria 

This paper addresses the current and future contributions of plant genetic resources and plant improvement to sustainable agriculture with reference to the activities of the International Center for Agricultural Research in the Dry Areas (ICARDA) in association with national programmes in West Asia and North Africa. These regions constitute the primary centers of diversity of crops such as wheat, barley, chickpea and lentil. Genetic erosion is being curtailed by germplasm collection and preservation. Selection for low-input cultivars of barley is conducted under low input conditions, and new cultivars of lentil and barley are often intentionally heterogeneous to stabilize their performance in dry rainfed areas. The importance of genetic differences in the cultivars on subsequent crops in the rotation and on straw quality for livestock is under study. Insect pests and diseases contribute to yield instability. Because of the potential adverse impact of pesticides on the fragile ecosystems of the region, integrated control strategies based on agronomic management, host plant resistance, biological control agents and strategic use of selective insecticides are being developed.

15  Newton-P-J; Myers-B-A; West-D-W  Reduction in growth and yield of Jerusalem artichoke caused by soil salinity. IRRIGATION SCIENCE (1991) 12 (4): 213-222, [En, Ref. 7] Inst. Sustainable Agriculture, Dep. Agriculture, Ferguson Road, Tatura, Victoria 3616, Aust  

The salt tolerance of irrigated Jerusalem artichokes (Helianthus tuberosus L.) was assessed in terms of biomass of both above ground parts and tubes in greenhouse and field trials. Salinity of irrigation water ranged from 0.7 to 12 dS m-1 in the greenhouse trial and from 0.2 to 10 dS m-1 in the field trial. Yield response of the dry matter of tubers of greenhouse-grown plants and of above ground parts of greenhouse-grown and field-grown plants, fell within the moderately tolerant category of Maas and Hoffman (1977). However, tuber yields in the field on a heavy clay loam fell within the moderately sensitive category, described by the equation, Y = 100-9.62 (EC-e-0.4), where Y = yield (t ha-1) as a % of that under non-saline conditions and EC-e = electrical conductivity of saturation extract in the rootzone (0-30 cm). The Cl concentration of leaves increased linearly with increasing external salinity and increased from tubers to stems to leaves. In contrast, leaf Na remained low except at the highest salinities, despite consistently higher stem Na, indicating some mechanism for restriction of leaf Na up to a certain external salinity.

16       Goldberg-J-J; Wildman-E-E; Pankey-J-W; Kunkel-J-R; Howard-D-B; Murphy-B-M  The influence of intensively managed rotational grazing, traditional continuous grazing, and confinement housing on bulk tank milk quality and udder health.  JOURNAL OF DAIRY SCIENCE （1992）75 (1): 96-104, [En, Ref. 6] Dep. Animal Health Sciences, Animal Health Section, Univ. Vermont, Burlington, Vt. 05401, USA 

Monthly bulk tank milk samples and veterinary records were analyzed for 1 yr on 15 Vermont dairy farms. Data were evaluated using ANOVA to compare effects of grazing management systems on milk quality and udder health. Systems evaluated were intensively managed rotational grazing, traditional continuous grazing and confinement housing. Bulk tank samples were evaluated for standard plate count, bacterial type counts on tryptose-blood-esculin agar, and SCC. Veterinary records were evaluated for incidence of clinical mastitis, udder edema, and teat injuries. Within- and between-treatment group analyses were conducted by season, herd size, and udder sanitation systems. Mean standard plate counts were lower in rotationally grazed herds than counts of confined herds during the grazing season. Similarly, rotationally grazed herds with fewer than 60 cows had lower standard plate counts than confined herds of similar size. Mean bulk tank counts of streptococci other than Streptococcus agalactiae during the grazing season differed among treatments. The lowest counts occurred in rotationally grazed herds. Among herd using predip products recognized as efficacious, fewer streptococci other than S. agalactiae were isolated from bulk tank milk of rotationally grazed herds than confined herds. Rotationally grazed herds using postdips recognized as efficacious had lower SCC than those using unrecognized postdips. No udder health differences were observed among grazing treatments.

17  Karlen-D-L; Berry-E-C; Colvin-T-S; Kanwar-R-S  Twelve-year tillage and crop rotation effects on yields and soil chemical properties in northeast Iowa. COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS （1991）22 (19-20): 1985-2004, [En, Ref. 6] USDA-Agric. Res. Serv., Natl. Soil Tilth Lab., 2150 Pammel Dr., Ames, Iowa 50011, USA

Long-term tillage and crop management studies may be useful for determining crop production practices that are conducive to securing a sustainable agriculture. Objectives of this field study were to evaluate the combined effects of crop rotation and tillage practices on yield and changes in soil chemical properties after 12 years of research on the Clyde-Kenyon-Floyd soil association in northeastern Iowa. Continuous corn (Zea mays L.) and a corn-soybean (Glycine max L. (Herr)) rotation were grown using moldboard plowing, chisel plowing, ridge-tillage, or no-tillage methods. Tillage and crop rotation effects on soil pH, Bray P1, 1M NH4OAc exchangeable K, Ca, and Mg, total C, and total N in the top 200 mm were evaluated. Profile NO3-N concentrations were also measured in spring and autumn of 1988. Crop yields and N use efficiencies were used to assess suitability. Bray P1 levels increased, but exchangeable K decreased for all cropping and tillage methods. Nutrient stratification was evident for no-tillage and ridge-tillage methods, while the moldboard plowing treatment had the most uniform soil test levels within the 200 mm management zone. Chisel plowing incorporated fertilizer to a depth of 100 mm. Soil pH was lower with continous corn than with crop rotation because of greater and more frequent N applications. Profile NO3-N concentrations were significantly different for sampling depth and among tillage methods in spring 1988. In autumn the concentrations were significantly different for sampling depth and for a rotation by tillage interaction. Estimated N use efficiencies were 40 and 50 kg grain per kg N for continuous corn, and 48 and 69 kg grain per kg N for rotated corn in 1988 and 1989, respectively. The results suggest that P fertilizer rates can be reduced, but K rates should probably by increased to maintain soil-test levels for this soil association. Crop rotation and reduced tillage methods such as ridge-tillage or chisel plowing appear to meet the criteria for sustainable agriculture on these soils. 

18  Hamblin-A  Sustainable agricultural systems: What are the appropriate measures for soil structure?  AUSTRALIAN JOURNAL OF SOIL RESEARCH （1991）29 (6): 709-716, [En, Ref. 5] Bureau Rural Resources, P.O. Box E11, Queen Victoria Avenue, Parkes, A.C.T. 2601

Sustainable agriculture implies time-scales which are long relative to human lifespan, and the maintenance of productive capacity from the resource base. To evaluate whether agricultural systems are sustainable we need appropriate biophysical and socio-economic measures. Monitoring the status of soils will need some description of their capacity to store and transmit water, nutrients and gases for plants and microorganisms. Most physical and chemical properties of soils which regulate this storage and transmission are time-consuming and complex to measure. Moreover, they are not readily adapted to the requirements of large-scale, long-term environmental monitoring. Robust surrogates are required which can be unambiguously interpreted. A range of such surrogates and their application at different spatial scales is discussed.

19  Harmsen-R  The theory of sustainable agriculture: Opportunities and problems.  PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF ONTARIO （1990）121 (0): 13-24, [En, Ref. 3] Biol. Dep., Queen's Univ., Kingston, Ontario K7L 3N6, Canada 

The concept of sustainable agriculture is approached using the tenets of biological equilibrium theory as illustrated by the process of ecological succession. Modern agricultural systems are recognized as man-made early successiona ecosystems, maintained in a state of severe disequilibrium by continuous input of energy and chemicals that cannot continue in perpetuity. An argument is made for the development of agricultural management practices and protocols using higher informational content in lieu of increasing energy inputs. The identification and manipulation of domains of local equilibrium in agricultural systems may allow for the development of localized sustainability. Such development depends on three separate approaches: 1) biological research and education; 2) rapid, high-tech manipulation and feedback; 3) altered (reduced?) yield objectives. Both opportunities and problems are illustrated with an example of integrated pest management research dealing with one subsystem of orchard management: tentiform leafminer and mites. Current leafminer control is exclusively chemical, and creates as a byproduct a serious mite problems. However, apparently stable interactive states have been identified between the leafminer, its parasites, the phytophagous mites and their predators. Experimental management protocols appear to be capable of managing the orchard system at or near these stable states, and operate at sustained productivity without large pesticide inputs, and with comparable yields to conventional control methods. Problems such as high research and monitoring costs are identified and discussed.

20  Dalal-R-C; Strong-W-M; Weston-E-J; Gaffney-J  Sustaining multiple production systems: 2. Soil fertility decline and restoration of cropping lands in sub-tropical Queensland. TROPICAL GRASSLANDS （1991）25 (2): 173-180, [En, Span. summ. Ref. 2] QWRI, P.O. Box 2282, Toowoomba, Qld 4350, Aust

Fertile soil is the basis of sustainable agriculture. Continuous cultivation and cereal cropping lead to the depletion of soil fertility, low crop yield and poor grain quality. It is estimated that 1.2M ha of the total cropping area of 1.5M had in southern sub-tropical Queensland (Australia) are affected by soil fertility decline, with a consequent reduction in crop yield and grain quality values at an output loss of 324M/yr. There is an urgent need to adopt fertility restorative practices to maintain economically viable farming enterprises. Legume based leys, grain legumes, fertiliser N and zero-tillage were compared for their effectiveness in restoring or maintaining soil fertility and for sustaining wheat yield and quality on a fertility-depleted brigalow soil at Warra on the western Darling Downs. Both annual N fertilizer application and zero tillage accompanied by N application maintained wheat yields although they are uncertain options for long-term fertility restoration. The grain legume, chickpea, provided a moderate level of N supply to the following wheat crop but it is also an uncertian option for fertility restoration. Pasture leys based on annual and perennial legumes, with or without grasses, provide a useful option for fertility restoration. One year medic and lucerne leys contributed to soil N to a moderate level although lucerne leys may have an adverse effect on the moisture available for following crops. Grass-legume mixed pastures increased soil fertility as measured by an increase in soil total N. Of these options, pastures based on annual and perennial temperate legumes and tropical grasses have the potential to increase or maintain soil fertility. Legume leys and especially grass-legume pasture leys will play a key role in future ecologically and economically sustainable farming systems.

21  Caporali-F; Onnis-A  Validity of rotation as an effective agroecological principle for a sustainable agriculture.  AGRICULTURE ECOSYSTEMS & ENVIRONMENT.  1992, 41 (2): 101-113; [En, Ref. 9] Inst. Agron., Univ. Tuscia, Via S. Camillo de Lellis 01100 Viterbo,

Italy Agriculture in industrialized countries is based on specialized agroecosystems, where high yields are obtained from sequences of annual crops (cash crops) with large inputs of chemicals. A sustainable agriculture should conversely rely on major exploitation of native resources, i.e. sun energy, water from precipitations, atmospheric nitrogen, and soil organic matter. Crop rotation, based on the inclusion of polyannual legumens, is to be considered among the most powerful management practices for pursuing such aims because of its implications for maintaining soil fertility, saving energy and avoiding pollution. Results confirming the validity of this statement are presented. The residual effect on the succeeding crop (sunflower) of a long-term rotation, which included a four-year lucerne ley, in comparison with a sequence of annual crops, was investigated in a mediterranean environment (Central Italy). Similar yields were obtained in very contrasting conditions. Approximately up to 300 kg ha-1 seed yield and 1400 kg ha-1 oil yield recorded either with lucerne as the preceding crop, without any addition of inorganic-N and with mechanical weed control, or with safflower as the preceding crop, supplying sunflower with 130 kg ha-1 of inorganic-N and chemical weed control. The effects of the treatments on yield are also discussed.

22  Mackenzie-D-R  Progress in plant disease resistance research. FAO (FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS) PLANT PROTECTION BULLETIN (1991) 39 (4): 147-154, [En, Fr. and Span. summ. Ref. 7] United States Dep. Agric., Cooperative State Res. Service, Suite 330 Aerospace Build., 901 D Street SW, Washington, D.C. 20250-2200

The nature, application and dependability of plant disease resistance and the impact of the science of genetics is reviewed. Recent discoveries at population, cellular and molecular levels that have greatly expanded opportunities for conducting research on plant disease resistance are presented and breeding strategies for improved crop protection are summarized. Other issues discussed included progress made in understanding host-pathogen relationships: biological control, gene mapping and genetic engineering: low-input sustainable agriculture and integraged pest managements; and the need for international scientific calloboration on crop improvement policies and methodologies.

24  Banuelos-G-S; Cardon-G-E; Phene-C-J; Wu-L; Akohoue-S; Zamb RZUSKI-S  Soil boron and selenium removal by three plant species. PLANT AND SOIL (1993) 148 (2): 253-263 [En, Ref. 1] USDA-ARS Water Management Res. Lab., Fresno, CA 93727, USA

High concentrations of boron (B) and selenium (Se) naturally found in the environment are detrimental to sustainable agriculture in the western USA. Greenhouse pot experiments were conducted to study B and Se uptake in three different plant species; Brassica juncea (L.) Czern (wild brown mustard), Festuca arundinacea Schreb. L. (tall fescue), and Brassica napus (canola) were grown in soil containing naturally occurring concentrations of 3.00 mg extractable B kg-1 and 1.17 mg total Se kg-1 soil. During the growing season, four intermediate harvests were performed on wild mustard and tall fescue. Final harvest I consisted of harvesting wild mustard, canola, and clipping tall fescue. Final harvest II consisted of harvesting wild mustard, which had been planted in soil in which wild mustard was previously grown, and harvesting previously clipped tall fescue. The greatest total amount of above ground biomass and below surface biomass was produced by tall fescue. Plants were separated into shoots and roots, weighed, and plant tissues were analyzed for total B and Se. The highest concentrations of tissue B were recovered in shoots of wild mustard and canola at final harvest I, while roots from tall fescue contained the highest concentrations of B irrespective of the harvest. Tissue Se concentrations were similar in all plants species. Soils were analyzed for residual B and Se. Extractable soil B concentrations at harvest times were lowered no less than 32% and total Se no less than 24% for all three species. The planting of wild mustard, canola, or tall fescue can reduce water-extractable B and total Se in the soil.

25  Rangaswamy-A; Venkitaswamy-R; Premsekhar-M; Palaniappan-S  Sustainable agriculture for rice (Oryza sativa) based ecos  ystem.  INDIAN JOURNAL OF AGRONOMY (1992) 37 (2): 215-219, [En, Ref. 12] Dep. Agron., Tamil Nadu Agric. Univ., Coimbatore 641 003

With the meagre possibility of bringing additional area under plough, it is of immense importance to produce more for the ever-increasing population in the years to come. The study integrating crops with fish and poultry farming in the lowlands of Tamil Nadu (India) clearly indicated the best advantage over the conventional system of cropping. The study conducted for 3 years (1987-1990) indicated an additional income of Rs 15,320, Rs 11,574 and Rs 15,505/ha/year during first, second and third year respectively over conventional cropping.

26  Douds-D-D-JR; Janke-R-R; Peters-S-E  VAM fungus spore populations and colonization of roots ofmaize and soybean under conventional and low-input sustainable agriculture. AGRICULTURE ECOSYSTEMS & ENVIRONMENT (1993) 43 (3-4): 325-335, [En, Ref. 9] USDA-ARS ERRC, 600 E. Mermaid Lane, Philadelphia, PA 19118, USA 

Spore populations of vesicular-arbuscular mycorrhizal (VAM) fungi and formation of mycorrhizae in maize (Zea mays L.) and soybean (Glycine max (L.) Merr.) were studied in three farming systems: a conventional maize-soybean rotation and two low-input systems. Spore population were counted in soil samples obtained at planting and after harvest for two growing seasons. Maize and soybean root systems were sampled for mycorrhizae early in the growing season. Low-input plots tended to have higher populations of spores of VAM fungi than the conventionally farmed plots. Further, the readily identifiable species Gigaspora gaigantea (Nicol & Gerd.) Gerdemanna & Trappe, was more numerous in low-input plots (up to 30 spores 50 cm-3 soil) than in conventional plots (0 - 0.3 spores 50 cm-3 soil), suggesting farming system affected species distribution as well. Colonization of plants in the field did not always reflect VAM fungus spore populations at planting. Greenhouse bioassays showed 2.5-10 fold greater colonization of plants growing in soil from low- input than conventional systems. These results indicate that conventional farming systems yield lower levels of VAM fungi whereas low-input sustainable agriculture, with cover crops planted between cash crops, has greater populations of VAM fungi and potential to utilize the benefits of VA mycorrhizae. 

27  Blaikie-S-J; Mason-W-K  Restrictions to root growth limit the yield of shoots of irrigated white clover. AUSTRALIAN JOURNAL OF AGRICULTURAL RESEARCH (1993) 44 (1): 121-135, [En, Ref. 8] Dep. Agric., Kyabram Center, Inst. Sustainable Agriculture, R MB 3010, Kyabram 3620 

Pasture yields in irrigated northern Victoria are low. This experiment examined the degree to which restrictions in root growth explained the low shoot yield of white clover (Trifolium repens) grown in irrigated soils. Soils were collected as intact cores from various field sites producing from well above to well below average pasture growth. A vegetative cutting of white clover was planted into each soil core and the growth of the shoot and root systems was monitored over a 38 day period by a series of destructive harvests. All plants were managed to minimize water, oxygen or nutrient stresses. There were large effects of treatments on the productivity of plants with growth in the soil cores reflecting the field productivity of each soil. This suggested that despite managing the cores carefully, it was not possible to overcome the limitations to plant yield that occur in these soils in the field. The most productive soil was one for which the profile had been physically modified. Measures of soil physical properties (bulk density, air-filled porosity, volumetric water content, penetrometer resistance) were collected from the field sites when the soil was at field capacity, but it was not possible to identify which of these were associated with the differences in productivity between soil core treatments. No measures of the soil physical conditions were made in the cores, but it is possible that the field data did not accurately reflect conditions in the soil cores, particularly during each daily watering. There were strong correlations between shoot and root production whether measured in terms of dry weight or morphological characteristics. The most important characteristic of highly productive soil was the capacity to support the rapid proliferation of a large root system. Improved forage yield will only be possible if the potential for white clover to produce roots in irrigated soils is increased. 

28  Liu-G  Recycling of nutrient elements and developing of sustainable agriculture. ACTA PEDOLOGICA SINICA (1992) 29 (3): 251-256, [Chin, Ref. 4] Chinese Acad. Agric. Sci., 100081 China 

More than 2000-year history of agriculture in China has demonstrated the grain yield could be sustained and the soil productivity could be maintained and gradually improved through recycling the nutrient elements and raising the efficiency of organic manure. The input of non-agricultural material and energy is a most effective way to increase crop yield and is one of important characteristics of modern agriculture. But there is a tendency in some regions that the farmers prefer only chemical fertilizer. The long-term application of sole chemical fertilizers will cause many soil problems and exert a bad influence on crop quality and human health. Particular attention sould be given to the development, production and application of the organic manures, so as to solve the problem of organic manures, to improve soil properties and to develop sustainable agriculture.

29  Budelman-A; Van-Der-Pol-F  Farming system research and the quest for a sustainable agriculture. AGROFORESTRY SYSTEMS  (1992) 19 (3): 187-206, [En, Ref. 4] Agricultural Dev., Dep. Royal Tropical Inst., Mauritskade 63, 1092 AD Amsterdam, Neth

This paper brings together information from four sites in sub-Saharan Africa where FSR&D projects are located (Mali, Benin, Zambia and Tanzania), supported by the Royal Tropical Institute of The Netherlands. Common environmental constraints to agricultural productivity are analyzed, when an emphasis on aspects of soil fertility maintenance. It is shown that when plant nutrients are valued against market prices, annual crop production systems are inefficient due to considerable losses of nutrient resources (e.g, soil erosion) and economically unviable because of unfavourable input and producer price ratios. Technically solutions are available that make agriculture sustainable, but its output is likely to be reduced when accepting the need for environmental protection at various levels of integration (cropping system, field/farm, village territory, etc.), since marginal land must be left under natural vegetation, and various forms of buffering elements must be installed on farms. The costs of protective measures (space, labour, energy in community organization) cannot be raised based upon local resources currently available. Making small farmer agriculture in the tropics sustainable and environmentally sound begins by improving economic conditions for farmers, raising producer income and lowering prices for inputs. 

30  Khalil-S; Loynachan-T-E; Mcnabb-H-S-JR  Colonization of soybean by mycorrhizal fungi and spore pop  ulations in Iowa soils. AGRONOMY JOURNAL (1992) 84 (5): 832-836, [En, Ref. 1]Dep. Agron., Iowa State Univ., Ames, Iowa 50011

Mycorrhizae, a mutualistic association between fungi of the family Endogenous and higher plants, have been studied extensively in the greenhouse, but much less is known about the natural ecology of these fungal-plant associations in field soils. A better understanding of the mycorrhizae of agronomic crop is needed because of their potential involvement in systems of sustainable agriculture. This study reports on the extent of root colonization by mycorrhizal fungi, the distribution of mycorrhizal fungal spores in the rhizosphere, and the mycorrhizal fungal genera associated with soybean (Glycine max (L.) Merr.) in 15 Iowa soils. Results indicated that soybeans roots from most soils, in spite of some soils having very high soil-test P levels, were extensively colonized (60-100%) by vesicular-arbuscular mycorrhizal (VAM) fungi. Colonization was determined by evaluating the percentage of root segments with VAM fungi. The average colonization of plant roots from all soils was 89%, and the average Bray P1 soil-test value was 60.3 mg kg-1 (values greater than 30.5 are considered by the Iowa State Soil Testing Laboratory to be very high). Abundant colonization was unexpected in these high-P fertility soils because most authors report extensive colonization to occur mainly in plants growing in soils in low fertility. The VAM fungal spores were quite common in all rhizosphere soils sampled and ranged from 66 to 998 spores 100 g-1 soil. Total spore counts were significantly different among soil series (P lt 0.001) and within soil series (P lt 0.01). A negative correlation (P lt 0.05) was found between soil organic matter, P, and VAM fungal colonization. For VAM fungal genera (Glomus, Gipaspora, Acaulospora, and Scutellospora) were found associated with soybean rhizosphere soil. Among these, Glomus was the most abundant.

31  Izquierdo-Juan; de-la-Riva-Gustavo-A  Plant biotechnology and food security in Latin America and the Caribbean. EJB-Electronic-Journal-of-Biotechnology. (2000) April 15, 2000; 3 (1 CITED MAY 2, 2000): 1-13. [En]. FAO Regional Office for Latin America and the Caribbean, REDBIO/FAO-Technical Co-operation Network on Plant Biotechnology for Latin America and the Caribbean, Santiago, Chile

Agriculture is expected to feed an increasing population, forecasted to reach 8 billion by 2020, out of whom 6.7 billion will be in developing countries where the carrying capacity of agricultural lands will soon be reached. In Latin American and the Caribbean (LAC) countries, in spite of the abundance of natural resources and continued investments in development, poverty and food insecurity affect more than 55 percent of the rural population. Fifteen years ago, plant biotechnology comprised only a few applications of tissue culture, recombinant DNA technology and monoclonal antibodies. Today, genetic transformation, and marker-aided selection and breeding are just a few of the examples of the applications in crop improvement with profound implications for the LAC Region. Plant biotechnology applications must respond to increasing demands in terms of food security, socio-economic development and promote the conservation, diversification and sustainable use of plant genetic resources as basic inputs for the future agriculture of the Region. Food security is defined by FAO as the access by all people at all times to the food needed for a healthy and active life. The concept means the achievement of the food self-sufficiency, and guarantees that this condition will be sustained in the future. Food security implies reaching productive growth and the preservation of the environment. Malnutrition affects 15% the population in Mexico, Central America and the Caribbean and 13% of the population in South America, while the Region represents nearly 23% of the arable lands and 12% of the world cultivated areas. Plant biotechnology offers several possibilities for increasing productivity, diversification and production, while developing a more sustainable agriculture. It includes biopesticide production, plant tissue culture techniques, and the use of advanced molecular biology techniques for plant transformation, genomic analysis coupled with breeding and plant-disease diagnoses. Agricultural biotechnology in the LAC Region is characterised by a repetitive and academic model, where many of the project objectives do not respond to the real needs of crop production and food security in the Region. Many small research teams in universities or agricultural institutions, poorly connected and/or integrated, have a high dispersion of facilities and qualified labor force. The database of REDBIO/FAO in 1999, register 539 laboratories affiliated in 23 countries of the Region. 83% of the member laboratories have less than 10 researchers and technical personnel and only 72% of them have three postgraduat.

32  Fujihara-Shinsuke; Yoshida-Masanori  Allelopathy of hairy vetch, Vicia villosa ROTH. and its application for crop production as mulching material. Bulletin-of-the-Shikoku-National-Agricultural-Experiment-Station. (2000), March, 2000; (65): 17-32. [Ja.] 

Allelopathic action of leguminous plant hairy vetch (Vicia villosa ROTH.) was examined using the filter glass method or a pot test in which dry shoot from hairy vetch was added to the soil surface. The growth of lettuce and spring weed Sonchus oleraceus L. was suppressed on the glass filter which had been inserted between the soil surface and covering shoot of hairy vetch during four rainy days. Dry shoot (including leaf, stem and vein) of hairy vetch harvested in May exhibited the same allelopathic effect since germination or growth of summer weeds such as Digitaria adscendens HENR. and Polygonum persicaria L. was severely inhibited by the addition of the dry shoots into the pot. Chenopodium album L. was, however, not affected by these tests, indicating the selective inhibition of the allelochemicals from hairy vetch for weeds. For the development of a safe and labor-saving weed control method without the use of herbicides, this pasture plant was applied as a mulching material in crop cultivation. Covering the row with dry shoot from hairy vetch gave the same level of weed suppression as rice straw mulching, with a 60%-80% reduction of weed biomass, compared with the control plot without mulching material. More effective weed suppression was observed in the live-mulching method in which the row was covered with the aerial parts of living hairy vetch. In addition to the weed suppression effect, the hairy vetch live-mulching method resulted in the improvement of various soil physical properties as follows. 1) Increase in the moisture content due to the prevention of water evaporation from the soil surface. 2) Stabilization of the soil temperature and decrease in the excessive increase of the soil surface temperature under the summer solar radiation. 3) Increase in the water permeability and improvement of drainage due to the increase in the amount of soil macropores, possibly due to the extension of hairy vetch roots and the movement of small animals induced around the underground part of hairy vetch. 4) Decrease of soil hardness or reduction of soil hardness due to the increase in the amount of soil macropores as described above. As a result of soil improvement and green manure effect of hairy vetch live-mulching, some crops showed good growth in the early phase and enlargement of the underground parts, and their yield increased compared with that of the weeding non-mulching plot. Thus, the live-mulching cultivation method seems to be highly suitable for various crops, especially those utilizing tubers or tuberous roots such as Ipomoea batatas Poiret and Zinger officinalis Rosc biological weed control. Present cultivation methods may contribute to the promotion of low input sustainable agriculture without the use of compound fertilizers and herbicides.

33  Blair-Nelly; Crocker-G-J  Crop rotation effects on soil carbon and physical fertility of two Australian soils.  Australian-Journal-of-Soil-Research. (2000), 38 (1): 71-84. [En] Agronomy and Soil Science, University of New England, Armidale, NSW, 2350, Australia

The effect of using different crop rotations, including legumes and fallows, on soil structural stability, unsaturated hydraulic conductivity, and the concentration of different carbon fractions was examined in a long-term rotation trial established in 1966 on a Black Earth (Pellic Vertisol) and a Red Clay (Chromic Vertisol) soil. There was a large decrease in the concentration of soil carbon fractions following cropping and cultivation on both soils. The inclusion of some legume rotation crops resulted in an increase in labile carbon concentrations compared with continuous wheat or a long fallow treatment. Aggregate stability to wetting under both immersion and tension wetting was reduced as a result of cropping and cultivation for both soil types. However, there was an improvement in aggregate stability with immersion wetting, on the Red Clay soil, for the lucerne (Medicago sativa), clover (Trifolium subterraneum), and continuous wheat (Triticum aestivium) treatments compared with the long fallow. Similar results were found for the Black Earth soil; however, on this soil the medic (Medicago scutella) rotation also showed an improvement in soil structure. On the Red Clay soil there was a decrease in hydraulic conductivity (K) with cropping, at all tensions measured. K for the Black Earth soil was higher at 30 and 40 mm tension on the cropped soil than on the uncropped reference soil, but at 10 mm tension the reference soil had a higher K value than all rotations except the lucerne. There was a significant correlation between labile carbon and all determinations of aggregate stability for the Red Clay soil. Farmers should be encouraged to eliminate long fallowing and to adopt no-till techniques combined with the return of residues from either the primary crop or rotation crops which have a slower breakdown rate, as this management is likely to have a better potential for increasing soil carbon content and improving soil structure. The investigation of ways to better increase the quantity and quality of soil organic matter and hence soil chemical and physical fertility is necessary if long-term sustainable agriculture is to be possible. 

34  Khichar-M-L  Nature farming for sustainable agriculture. Annals-of-Biology-Hissar. June, 2000; 16 (1): 83-84. [En]. Department of Agricultural Meteorology, CCS Haryana Agricultural University, Hisar, 125 004, India 

Nature farming for sustainable agriculture is of paramount importance because of the environmental damage and degradation of natural resources that results from the current production practices of modern agriculture. This would not only increase the quality of production but would also help to preserve the natural ecosystem simultaneously for the benefit of future generation. Hence, there is strong need to educate and motivate the farmers for adoption of production technologies appropriate and suitable for nature farming.

35  Liu-Guobin  Soil conservation and sustainable agriculture on the Loess Plateau: Challenges and prospects.  Ambio-. Dec., 1999; 28 (8): 663-668. [En].Institute of Soil and Water Conservation, Chinese Academy of Sciences and Ministry of Water Resources, 26 Xinong Road, Yangling, Shaanxi, 712100, China 

The Loess Plateau with its deep loess and severe soil erosion constitutes a special region of the world. This paper discusses soil conservation, sustainable agriculture, and the prospectives for the Loess Plateau in relation to the Chinese economic development that is expected in the next century. The Loess Plateau region, covers 5 provinces, and stretches over an area of 0.62 million km2. Erosion has affected 45% of the area, with an average soil loss of 3720 tonnes (t) km-2 yr-1. The soil depth is 50-200 m which is typical for undeveloped areas in China. In the past 20 years, the Chinese government has given special attention to the integrated control of soil erosion and development of sustainable agriculture on the Plateau. Sustainable agriculture in this region should be based on rational land use including self-sufficiency in grain production, the protection of woodlands, and commercial fruit trees, and animal industry, in order to make full use of natural resources. Scientists have presented a 28 characters strategy and conservation eco-agriculture criteria for the watershed. Research on water erosion, and on soil and water conservation have led to the development of agricultural systems that are sustainable, Watershed-scale comprehensive management schemes, and reforestation have led to the conservation of water and to improved productivity and an increase in farmers' income. By 2000, the Plateau will be able to produce 50 million tonnes of grain to feed the people in the region. The Plateau with its land resources, agricultural resources, and rich mineral reserves (coal, oil), will play an important role in China's economic development in the 21th century.

36  Li-Wenhua; Min-Qingwen  Integrated Farming Systems: An important approach toward sustainable agriculture in China.  Ambio-. Dec., 1999; 28 (8): 655-662. [En].  Datun Road, Andingmen Wai, Building 917, Beijing, 100101, China

Rooted in thousand of years of traditional Chinese agricultural practices and techniques, the Integrated Farming System (IFS) is planned and widely practiced in different regions according to the principles of agronomy, ecology, economics and systems science. Its purpose is to establish agroecosystems with high efficiency and sustainability. Because the Chinese IFS makes it possible to meet the requirements of sustainable agriculture in China, it has been recognized by different levels of governments and by farmers. This paper present an overview of the IFS concept, principles, development, history and current status, classification, typical models, as well as trends for future development.

37  Mpepereki-S; Javaheri-F; Davis-P; Giller-K-E  Soyabeans and sustainable agriculture. 'Promiscuous' soyabeans in southern Africa. Field-Crops-Research. March, 2000; 65 (2-3): 137-149. [En]. Department of Soil Science and Agricultural Engineering, University of Zimbabwe, MP167, Harare, Zimbabwe 

Promiscuously nodulating varieties of soyabean have been developed which nodulate abundantly and effectively in most soils in southern Africa. Bred from genotypes collected in East Asia these promiscuous varieties nodulate with fast and slow-growing rhizobia representing several different genera. The symbiotic interaction between different soyabean genotypes and different rhizobial isolates varies widely both in terms of ability to nodulate and effectiveness in N2 fixation, but all plant genotypes tested, including varieties considered to be highly specific, nodulated with indigenous isolates in at least one soil. Promiscuity in nodulation allows soyabean to be introduced into a range of environments where lack of suitable inoculants would otherwise preclude growing the crop. Smallholder farmers need only access to seed to be able to grow soyabean, which brings multiple benefits in improved household nutrition from the high protein and oil content, cash income from sales of the crop and inputs of N which enhance soil fertility and contribute to the sustainability of their cropping system. Promiscuous soyabean varieties therefore represent a highly appropriate technology for cultivation of soyabeans for smallholder farmers, whereas use of varieties with greater yield potential together with rhizobial inoculants is an appropriate technology for commercial production of soyabeans by farmers who have ready access to agricultural inputs.

38  Leonardos-O-H; Theodoro-S-H; Assad-M-L  Remineralization for sustainable agriculture: A tropical perspective from a Brazilian viewpoint. Nutrient-Cycling-in-Agroecosystems. Jan., 2000; 56 (1): 3-9. [En]. Centro de Desenvolvimento Sustentavel, CDS/UNB. SAS Q.5, Bl.H 2o Andar, 70070-914, Brasilia, Brazil Current Latin American tropical agriculture is not sustainable.

It has become dominantly large-scale, bringing irreversible environmental damages such as devastation of the flora and the fauna and soil-degradation for vast tracks of land. Instead of bonding man to the land, it is bringing unemployment and rural exit. Furthermore, a land management model has been developed with technology that has been transferred from countries with temperate soils without taking into account basic climatic, mineralogical, geochemical, ecological and cultural differences, which are present in our tropical ecosystem. One such technology has been the indiscriminate use of highly soluble NPK fertilizers. Under deep leached conditions, this strategy does not bring nutrient conservation. As an alternative, or as a support to those 'chemical' fertilizers, and as an important step towards sustainable development, we suggest the use of native-rocks (stone meal) as the ultimate way to restore to the leached tropical soils, a balanced inorganic compositionon which plant growth and biodiversity can thrive.

39  McSorley-R  Host suitability of potential cover crops for root-knot nematodes.  Journal-of-Nematology. Dec., 1999; 31 (4 Suppl.): 619-623. [En].  Department of Entomology and Nematology, University of Florida, Gainesville, FL, 32611-0620, USA

Several potential cover crops were evaluated for their susceptibility to Meloidogyne arenaria race 1, M. incognita race 1, and M. javanica in a series of five greenhouse experiments. No galls or egg masses were observed on roots of castor (Ricinus communis), cowpea (Vigna unguiculata cv. Iron Clay), crotalaria (Crotalaria spectabilis), or American jointvetch (Aeschynomene americana). Occasional egg masses (rating ltoreq1.0 on 0-5 scale) were observed on marigold (Tagetes minuta) in one test with M. incognita, on sesame (Sesamum indicum cv. Paloma) in a test with M. arenaria, and on sunn hemp (Crotalaria juncea cv. Tropic Sun) in 1 of 2 tests with M. incognita; otherwise, these crops were free of egg masses. Numbers of second-stage juveniles (J2) hatched from eggs per root system were low (ltoreq10/pot) for the above-mentioned crops. Egg-mass levels and numbers of hatched J2 of M. incognita on pearl millet (Pennisetum typhoides, Tifleaf II hybrid) were comparable to those on a susceptible tomato (Lycopersicum esculentum cv. Rutgers). In a test with M. arenaria, egg mass levels and numbers of J2 on Japanese millet (Echinochloa frumentacea) were similar to those on tomato. Japanese millet was susceptible to each of the nematode isolates tested. However, several of the crops evaluated were very poor hosts or non-hosts of the nematode isolates, including several legumes (cowpea, crotalaria, jointvetch, sunn hemp) that have potential use in both nematode and nitrogen management.

40  Olsson-E-Gunilla-A; Austrheim-Gunnar; Grenne-Synnove-N  Landscape change patterns in mountains, land use and environmental diversity. Mid-Norway 1960-1993.  Landscape-Ecology. Feb., 2000; 15 (2): 155-170. [En]. Department of Botany; Plant Ecology, Norwegian University for Science and Technology, N-7491, Trondheim, Norway

The Norwegain mountains have had a central role in the subsistence agroecosystems by providing vast biological resources for humans and their livestock since 4000-3500 BP as indicated by paleoecological records. Later with the development of the summer farming system the use of the mountains was intensified. This long-term use of the mountains has shaped a montane cultural landscape by livestock grazing, mowing for hay, fuel collection and a variety of other uses. The result is a significant increase of the grassland areas at the expense of the forest. This study contributes examples from human shaped ecosystems in mountains where the fragmentation of semi-natural habitats is addressed. A set of landscape pattern indices commonly used in landscape ecological studies is also used here, and their ecological relevance in the present context is dealt with. The implications of changed land use for biodiversity conservation in those mountains and the relationships to future sustainable agriculture is also briefly discussed. 

41    Reggiani-Remo; Aurisano-Nicoletta; Mattana-Monica; Bertani-Alcide  Genotypic variation and relationship among nitrogen assimilation traits in Zea mays.  Revista-Brasileira-de-Fisiologia-Vegetal. Dec., 1999; 11 (3): 123-128. [En]. Istituto Biosintesi Vegetali, CNR, via Bassini 15, 20133, Milano, Italy 

An enhanced efficiency of absorption and utilization of nitrogen fertilizers by maize cultivars should be an important goal in view of a sustainable agriculture respecting the environment. In this study, we evaluated the variability in traits of nitrate absorption and assimilation (Km, Vmax, glutamine synthetase (GS) and ferredoxin-dependent glutamate synthase (FdGOGAT) activities) and the association among them using 40 inbred lines of maize. Our results showed that wide differences exist for all the traits examined. Some statistically significant associations between the biochemical traits were determined. The best inbred lines for uptake of nitrate (higher Vmax/Km ratio) and enzyme activities were identified. In particular, some inbred lines belonging to the Lancaster group or selected from ancient Italian maize populations exhibited high Vmax/Km ratio, whereas Stiff Stalk Synthetic inbred lines showed elevated enzyme activities for GS and Fd-GOGAT.

42    Van-Elsen-Thomas   Species diversity as a task for organic agriculture in Europe. Agriculture-Ecosystems and Environment. Jan., 2000; 77 (1-2): 101-109. [En]. Department of Ecological Agriculture, University of Kassel, Nordbahnhofstr. 1a, D-37213, Witzenhausen, Germany 

Different levels of biodiversity - species, biotopes and landscapes - can be differentiated and used for the assessment of the biotic environment of organic farms. Could the integration of species diversity into the cultivated land be a task for organic farming in the future? For hundreds of years agriculture supported the enrichment and the diversification of the vegetation in Central Europe. Nowadays many landscape elements are no more than relics of historical land use. Todays' intensive agriculture is considered to be the main agent responsible for the decline of plant species. What are the effects of sustainable ways of agriculture on biodiversity, especially on the diversity of arable field plants? Many investigations show positive effects of organic agriculture on the diversity of arable fields and grassland, too. A higher number of species and also more endangered 'red list' species are to be found in organic fields. Different effects of agricultural practices in organic farming on the weed flora are discussed. Today economic pressure leads to an improvement in mechanical weed control and undersowing. This shows that the aim of preserving, supporting and developing a diverse arable field flora cannot be reached automatically by converting to organic farming: an integration with the guiding image of organic agriculture is needed. Measures to support the richness of species of arable field plants in organic fields are shown. Many organic farmers are aware of correlations between an impoverished landscape and the appearance of pests and diseases and try to enrich the landscape with biotopes. Despite all the benefits of organic farming for nature the danger of separation arises in organic farming too: the separation of the landscape into 5% 'biotopes' where nature is allowed to develop and into 95% 'production area' being used intensively. One step further would be the development from separation to integration of biodiversity into the method of organic farming as a whole - a way which corresponds with modern aims of the nature conservation movement. The 'integrated table of landscape quality aspects' developed during the work of the concerted action 'The Landscape and Nature Production Capacity of Organic/Sustainable Agriculture' could be useful for the assessment of organic farms under various aspects of biodiversity. It might help to change the farmers' viewpoint and make them assess their particular landscape values and their landscape components with new eyes. 

43    Velasco-Leonardo; Perez-Vich-Begona; Fernandez-Martinez-Jose-M  The role of mutagenesis in the modification of the fatty acid profile of oilseed crops.  Journal-of-Applied-Genetics. 1999; 40 (3): 185-209. [En].  Institute for Sustainable Agriculture (CSIC), E-14080, Cordoba, Spain

Mutagenesis has played a major role in the development of novel variation for the fatty acid profile of oilseed crops. Although the first successful experiments were started in the 70s, most of the achievements in this field have been reported during the 80s and 90s. This paper summarizes the role of mutagenesis in the modification of the fatty acid profile of oilseed crops, the genetic basis of such modifications, and the consequences for plant breeding.

44       Rahman-Sanzidur; Thapa-Gopal-B  Environmental impacts of technological change in Bangladesh agriculture:  Farmers’ perceptance empirical evidance. Outlook on Agriculture Dec. 1999, 28 (4): 233-238 [En.] Department of Agriculture and Food Economics, University of Reading 4 Earley Gate, Witeknights Road, Reading RG6 6AR, UK.   

Concern about the environmental impacts of technological change in agriculture, and studies exploring farmers' perceptions of this issue are nascent. This paper provides an insight into the environmental impacts of modern agricultural technology, as perceived by Bangladeshi farmers. This is supported by material evidence such as soil fertility, and analyses of fertilizer and pesticide use, food grain production and fish catches. Farmers are well aware of the adverse environmental impacts of modern agricultural technology, although their awareness remains confined within the daily experience of their local environment, and is limited to matters such as soil fertility, fish catches and health effects. Farmers' perceptions of impacts such as toxicity in water and soils, are weak. Raising farmers' awareness of these tangible and intangible environmental impacts of modern agricultural technology is urgently needed for the development of sustainable agriculture.

45    Wenz-Peter-S  Pragmatism in practice: The efficiency of sustainable agriculture.  Environmental-Ethics. Winter, 1999; 21 (4): 391-410. [En]. Philosophy Department, School of Liberal Arts, University of Illinois, Springfield, Brookens 482, Springfield, IL, USA

Bryan Norton advocates using the perspectives and methods of American pragmatism in environmental philosophy. J. Baird Callicott criticizes Norton's view as unproductive anti-philosophy. I find worth and deficiencies in both sides. On the one hand, I support the pragmatic approach, illustrating its use in an argument for sustainable agriculture. On the other hand, I take issue with Norton's claim that pragmatists should confine themselves to anthrpocentric arguments. Here I agree with Callicott's inclusion of nonanthropocentric consideration. However, I reject Callicott's moral monism. In sum, I support pragmatic moral pluralism that includes nonanthropocentric values. 

45       Lapka-Miloslav; Cudlinova-Eva  Private farmer's attitudes to land, work and landscape: Interpretation of a case study in landscape ecological framework.  Ekologia-Bratislava. 1999; 18 (4): 401-412. [En]. Institute of Landscape Ecology, Academy of Sciences of the Czech Republic, Na sadkach 7, 370 05, Ceske Budejovice, Czech Republic

This paper looks at the private farmer's attitudes to their land, their own work and surrounding landscape. We employed a data coming from the socio-ecological research of family farmers in the South Bohemian landscape of the Czech Republic. Using farmer's attitudes to land, work and to landscape, the paper charts the ecological consequences of our cases in context with sustainable agriculture as so as in more theoretical context of landscape ecology. Farmer's attitudes mentioned above contains the potential to be a positive (from an ecological point of view) driving force for landscape preservation and land use. However, the application of these ecological positive attitudes is not a task only the farmer's internal factors. There are playing also great role external factors like agriculture policy, subsidies and last, but not least understanding of co-existence of natural and social patterns in rural landscape.

46        Rosa-E-A-S; Rodrigues-P-M-F  Towards a more sustainable agriculture system: The effect of glucosinolates on the control of soil-borne diseases. Journal-of-Horticultural-Science-and-Biotechnology. Nov., 1999; 74 (6): 667-674. [En].  Horticultural Section, Crop Science Department, University of Tras-os-Montes e Alto Douro, 5001, Vila Real Codex, Portugal

48       Amaro-Pedro Integrated protection, a favorable strategy in sustainable agriculture. Revista-de-Ciencias-Agrarias. April-June, 1999; 22 (2): 121-138. [Portuguese] 

49        Prasad-Rajendra  Sustainable agriculture and fertilizer use.  Current-Science-Bangalore. July 10, 1999; 77 (1): 38-43. [En].  Division of Agronomy, Indian Agricultural Research Institute, New Delhi, 110 012,

India Sustainable agriculture must produce enough food and fibre to satisfy changing human needs while conserving natural resources, maintaining the quality of environment and ultimately leading to community and gender equity. In the developed countries in Europe and to some extent in USA, chemical fertilizer has been held as a major culprit for environmental pollution, especially the nitrate enrichment of groundwater. However, evidence available also indicates that, animal slurry and septic cess pools largely contribute to nitrate enrichment of groundwater and also to environmental pollution with ammonia and nitrogen oxides (NOx). There are other sources of environmental pollution such as exhaust fumes from motor vehicles, flyash from thermal power plants and other industrial effluents. Developing countries such as India, reeling under population pressure with no additional cultivable land are forced to increase their fertilizer consumption, which as of today is much less than the actual crop needs. Nevertheless, we must learn lessons from the ill-effects of overuse of chemical fertilizer by developed countries and use it judiciously with a well-planned integrated plant nutrient supply system.

50       Thompson-P-B; Nardone-A Sustainable livestock production: Methodological and ethical challenges.  Livestock-Production-Science. Oct., 1999; 61 (2-3): 111-119.[En].  Department of Philosophy, Purdue University, West Lafayette, IN, 47907, USA

Research and policy for sustainable agriculture can be grouped into two broad paradigms. Those that define sustainability in terms of resource availability emphasize accounting for the rates at which resources are produced and depleted, and frame sustainability in light of strategies for conservation, regeneration and substitution for increasingly scarce resources. Those that define sustainability in terms of functional integrity emphasize dynamic system models of complex ecological and social processes of reproduction, and frame sustainability as relative in light of system vulnerability to anthropogenic stress. Broad comparison of these paradigms shows that a) there is currently greater research capacityy for analyzing issues under a resource availability paradigm, but that b) functional integrity approaches are more likely to produce ethical consensus over the goals and purposes of livestock production, relative to larger social purposes. The functional integrity paradigm is betterfor understanding the importance of biodiversity, the problem of spatial and temporal scale, and the relationship between society and ecology. Animal scientists should therefore develop a research approach to functional integrity and should also take advantage of a pluri- and interdisciplinary approach. The existing research capacity for resource availability should not limit animal science to addressing the sustainability of livestock production exclusively in resource availability terms.

51       Pelant-R-K; Chandra-B; Pu-J-B; Lohani-M; Suknaphasawat-N; Xu-G  Small ruminants in development: The Heifer Project International experience in Asia.  Small-Ruminant-Research. Nov., 1999; 34 (3): 249-257. [En]. Heifer Project International, 1015 Louisiana Street, Little Rock, AR, 72202, USA   

For more than half a century, Heifer Project International (HPI), a charitable organization headquartered in Little Rock, AR, has been providing livestock and training in animal husbandry and sustainable agriculture to developing areas throughout the world. Since 1944, more than four million families have been assisted. More than 20 different kinds of food- and income-producing animals have been provided for communities and families in over 110 countries worldwide. Annually, HPI has projects in approximately 40 countries. Intensive training in animal husbandry, environmentally sound animal agriculture practices and community development are all part of HPI's program. HPI has had a long history with using small ruminants, from sheep and goats to llamas and alpacas, around the world. Small ruminants are of a most convenient size and prolificacy for the small holders that HPI typically partners with, and they are among the most diverse and multipurpose of all livestock species. In Asia, HPI uses small ruminants in development programs in the People's Republic of China, the Democratic People's Republic of Korea, Thailand, India, Sri Lanka, Nepal, Bangladesh, Vietnam and Indonesia. All of these programs are with limited resource families living in marginal, rural conditions. The programs are geared toward increasing peoples' income and nutritional status, while enhancing their dignity and benefitting the ecology. 

52       Porazinska-L; McSorley-R; Duncan-L-W; Gallaher-R-N; Wheaton-T-A; Parsons-L-R  Relationships between soil chemical status, soil nematode community, and sustainability indices.  Nematropica-. Dec., 1998; 28 (2): 249-262. [En].

The development of more sustainable agronomic practices will benefit from detailed information on major components of the agroecosystem under various farming schemes. In this study, we focused on the long-term effects of different irrigation levels on the status of several macro- and micronutrients in the soil, and their relationship with the nematode components of the citrus soil ecosystem. In addition, the relationship of chemical (nutrient) and biological (nematode) measures to indices of sustainability was examined. Several soil chemical measures (Ca, Mg, Fe, Zn, and pH) were affected (P = 0.05) by water treatments involving different levels of irrigation intensity over time. About 40% of all nematode genera and half of the nematode community indices were significantly correlated with the chemical soil measures. Some of the chemical and nematode indices showed consistent patterns (P = 0.05) related to several components of sustainability in citrus agroecosystems (yield, profitabi lity, and water use efficiency). Since the "sustainability indices" reflect different aspects of sustainable agriculture, their usefulness in formulating recommendations requires prioritizing their relative importance. In our experiment, the relationships between omnivorous nematodes, the nematode maturity indices, and water use efficiency, and between irrigation level and profitability allowed us to suggest the optimum irrigation treatment (minimizing water overuse and maximizing profits), and to establish omnivorous nematodes and the nematode maturity indices as indicators of water management history.

53  Van-Hook-T  The conservation challenge in agriculture and the role of entomologists.  Florida Entomologist  1994, 77(1): 42-73 [En]. Dep. Entomol. and Nematol., Univ. Florida, Box 11060, Gainesville, FL 32611, USA 

Conservationists and agriculturists must work together toward the common goal of satisfying growing human population needs while maintaining natural resources and ecological processes critical to long-term human survival. The study of invertebrates has perhaps the greatest potential for contributing to this goal through theoretical, practical, and educational advancements. I discuss my view of the resulting challenge to entomologists with emphasis on insect conservation, sustainable agriculture, and environmental education. 

54  Tisdall-J-M  Possible role of soil microorganisms in aggregation in soils.  Plant and Soil (1994), 159 (1): 115-121, [En].  Dep. Food and Agric., Victoria, Inst. Sustainable Agriculture, Tatura, VIC 3616, AUL

In many soils, roots and fungal hyphae, especially those of vesicular arbuscular mycorrhizal (VAM) fungi, stabilize macroaggregates ( gt 250 mu-m diameter); organic residues, bacteria, polysaccharides and inorganic materials stabilize microaggregates ( lt 250 mu-m). This review discusses the factors (including other organisms) which affect VAM hyphae and their extracellular polysaccharides in soil, and the subsequent effect on stability of aggregates. The review also discusses the possible role of other organisms, including ectomycorrhizal fungi, in the stability of soil, and suggests future research.

55  Oberle-S   Farming systems options for U.S. agriculture: An agroecological perspective. Journal of Production Agriculture  (1994), 7 (1): 119-123,  [En]. USDA-Extension Serv., 214 National Soil Tilth Lab, Iowa State Univ., Ames, IA 50011, USA

Agricultural productivity gains since the 1950s have resulted from the development of farming systems that rely heavily on external inputs of energy and chemicals to replace management and on-farm resources. The intensity to which the natural environment has been modified to attain this productive capacity has directly resulted in degradation of the natural resources, notably land and water, that sustain these systems. The search for solutions to increasingly complex and interrelated agricultural problems including sustainable agriculture, environmental quality, food safety, and rural development requires a shift in both the scientific method and scale in which agricultural research is organized and conducted. Farming systems research and extension (FSRE) and other systems-oriented approaches fitted to agriculture are viewed as essential approaches for addressing complex agricultural problems, and for developing more efficient and sustainable farming systems. This article provides a brief synthesis of research information from several technical reports that were presented at a special symposium held during the American Society of Agronomy annual meetings in 1992. The reports cover a wide range of topics including FSRE, agricultural systems, systems engineering, information systems, and sustainable development. 

56  Hesterman-O-B; Thorburn-T-L  A comprehensive approach to sustainable agriculture: W. K. Kellogg's integrated farming systems initiative.  Journal of Production Agriculture (1994), 7(1): 132-134, [En].  Dep. Crop and Soil Sci., Mich. State Univ., Esat Lansing, MI 48824, USA 

Creating sustainable options for farming systems in the USA requires addressing both technological and nontechnological barriers. It is necessary to continue research, development, and validation of technologies that enhance agricultural productivity, environmental stewardship, and the quality of rural life. Changes in agricultural practices, however, will come about only when economic, policy, informational, and attitudinal barriers to adoption of these technologies are reduced. The W.K. Kellogg Foundation (WKKF), through its Integrated Farming Systems (IFS) Initiative, is supporting a cluster of community-based IFS projects. The goals of these projects are: (i) for farmers to adopt more integrated and resource-efficient farming systems that maintain productivity and profitability while protecting the environment and the personal health of farmers and their families, and (ii) to assist farmers and others in rural communities in addressing the barriers associated with adopting more resource-efficient and integrated systems. Each IFS project represents a collaboration among individuals and organizations within a community that share concern for the health of their farming systems in the short- and long-term. All WKKF-funded IFS projects are tied together through leadership development, information networking, and the addressing of public policy options necessary to foster sustainable systems. It is the hope of WKKF that it can assist those with an interest in and commitment to fostering more sustainable agriculture in overcoming the existing barriers and creating an agricultural system that can truly sustain many future generations. 

57  Hesterman-O-B; Wallner-S-J  Sustainable agriculture and the National Research Initiative.  Journal of Production Agriculture  (1994), 7 (1): 157-160,  [En].  Dep. Crop and Soil Sci., Mich. State Univ., East Lansing, MI 48824, USA 

In the Food, Agriculture, Conservation, and Trade Act (FACTA) of 1990 (the 1990 Farm Bill), Congress authorized expansion of funding and scope for competitively awarded federal money for agricultural research. Enabling legislation for the new National Research Initiative (NRI) stipulated that an emphasis be p on research supporting sustainable agriculture where appropriate, and that at least 30% of the funds be allocated to multidisciplinary research by 1993 with at least 20% of funds earmarked for mission-linked efforts. Challenges facing the NRI, in terms of agricultural sustainability, include: (i) how to incorporate appropriate stakeholder involvement, (ii) lack of consensus on how to operationalize the accepted definitions of "sustainable agriculture" and "mission-linked systems research," (iii) the need to assess social/economic impacts, (iv) perceived lack of opportunity for broadly multi- or interdisciplinary research, and (v) the dearth of proposals addressing issues of agricultural sustainability. If Congressional intent is to be met with the NRI, these issues must be addressed. Plant and soil scientists have a significant role to play in assisting the NRI to become more focused on promoting sustainable agriculture.  

58  Hetsen-H   Spatial conditions for a sustainable agriculture: Regional differentiation in the Netherlands. Landscape and Urban Planning  (1994), 27(2-4): 131-139, [En].Dep. Physical Planning Rural Develop., Wageningen Agric. Univ., Wageningen, NET

59  Wallace-A  Soil organic matter is essential to solving soil and environmental problems. Communications in Soil Science and Plant Analysis (1994), 25 (1-2): 15-28, [En]. Wallace Lab., 365 Coral Circle, El Segundo, CA 90245, USA 

Fifty per cent, more or less, of the soil organic matter from farm lands has been lost. The remainder is perhaps more resistant to loss and therefore is stable but that which has been lost was perhaps the most important half--it resisted erosion, it made soils permeable, it increased water-holding capacity and it produced healthy crops. The 50 per cent that has been lost is via two major mechanisms. One is loss per unit weight of soil by decomposition (mineralization) induced by cultivation, and the other is loss by erosion--loss by wash away and blow away of the surface soil which contains the most soil organic matter. Both mineralization and erosion are downhill processes. If they are not in equilibrium with reverse processes, the land cannot be sustainable. If agriculture is to be sustainable, we have to look at soil organic matter, first and foremost, as a means for maintaining stable-tillable soil. Mining of soil for nutrients and letting soil organic matter levels decrease can never result in sustainable agriculture. The role of soil organic matter as a source of nitrogen and other nutrients is less important than that of providing excellent physical and biological properties of soil. Use of water-soluble polymer soil conditioners can help. 

61  Wallace-A  Soil science, pesticides, and risk analyses. Communications in Soil Science and Plant Analysis (1994), 25 (1-2): 143-148, [En]. Wallace Lab., 365 Coral Circle, El Segundo, CA 90245, USA 

Tobacco will wipe out ten percent of the world's population at its present level of use. Cancer of various kinds is the major effect. Over the life span of 70 years, this means that about 100,000 per million will die of tobacco-induced cancer in the USA. There will be an equal number of cancers for other reasons. Many natural products in food we eat and even the air we breath can induce cancers. Legislation controlling use of pesticides aim at keeping the risk of cancer at less than one in a million over a life span of 70 years. Against a background of 200,000 per million or even half that, one in a million is virtually impossible to detect, even with the best of science. Risk analysis is far from being an exact science. The procedures used to assess risk, even though full of assumptions, are reasonably safe. Most likely they err on the safe side by orders of magnitude. The Delaney Clause, California Proposition 65 which banned all pesticides known to be carcinogenic in California, and failed California Big Green of 1990 all mean well but they detract from a farmer's ability to deal with the more real problems of creating a sustainable agriculture. The present analytical revolution has increased fears of pesticides but it should do the reverse; perceived risk is a bigger problem than real risk.

62  Wallace-A  Evolution of the low income per acre--large number of acres per farm--highly mechanized--monoculture--not too sustainable agriculture.  Communications in Soil Science and Plant Analysis (1994), 25 (1-2): 61-66,  [En]. Wallace Lab., 365 Coral Circle, El Segundo, CA 90245, USA 

The size of farms in the USA has steadily increased in recent decades. Farm size is part of the controversy about sustainable agriculture. The methodology for managing large-scale farms is not all conducive to the procedures which can give more sustainability. 

64  Wallace-A  Sense with sustainable agriculture. Communications in Soil Science and Plant Analysis (1994), 25(1-2): 5-13, [En]. Wallace Lab., 365 Coral Circle, El Segundo, CA 90245, USA 

Conventional agriculture appears to be decreasing in energy efficiency and has some adverse effects on the environment. Therefore, the marriage of agriculture and ecology is welcome, but the debate on how to achieve goals for sustainability is far from concluded. The most important aspect of sustainability is creating systems that have an indefinite future. This point is too often ignored. A number of "terrible" questions can be asked about sustainability. A list of 24 ingredients required for a sustainable agriculture is given. We want sustainable agriculture to be scientific, safe and sensible. People won't stop eating if the agriculture is not sustainable, but someday there may be little to eat unless sustainability is seriously addressed.

66  Caswell-Chen-E-P; Williamson-V-M; Westerdahl-B-B  Applied biotechnology in nematology. Journal of Nematology (1994), 25 (4 SUPPL.): 719-730,  [En].  Dep. Nematol., Univ. Calif., Davis, CA 95616, USA

During the past two decades, rapid advances in biotechnology and molecular biology have affected the understanding and treatment of human and plant diseases. The human and Caenorhabditis elegans genome-sequencing projects promise further techniques and results useful to applied nematology. Of course, biotechnology is not a panacea for nematological problems, but it provides many powerful tools that have potential use in applied biology and nematode management. The tools will facilitate research on a range of previously intractable problems in nematology, from identification of species and pathotypes to the development of resistant cultivars that have been inaccessible because of technical limitations. However, to those unfamiliar or not directly involved with the new technologies and their extensive terminology, the benefits of the advances in biotechnology may not be readily discerned. The sustainable agriculture of the future will require ecology-based management, and successful integrated nematode management will depend on combinations of control tactics to reduce nematode numbers. In this review we discuss how biotechnology may influence nematode management, define terminology relative to potential applications, and present current and future avenues of research in applied nematology, including species identification, race and pathotype identification, development of resistant cultivars, definition of nematode-host interactions, nematode population dynamics, establishment of optimal rotations, the ecology of biological control and development of useful biological control agents, and the design of novel nematicides.

67  Luh-C-L  Sustainable agriculture and rural development the importance of building up water resources through reforestation.  Journal of the Agricultural Association of China New Series 1993, (163): 1-7 [Chin] 

Sustainable agriculture is recognized as a modern nomenclature, yet it represents its aged farming practiced and has been employed by Chinese farmers since ancient times as early as nearly 4,000 years ago. Nowadays, there are a number of new terms bearing the nature or content more or less similar to sustainable agriculture. In a word, this sustainable agriculture appearing to be a modern and more scientific terminology is a good sign of the importance of preserving natural resource for farming in this advanced technology era, with respect to reconsidering the value of human life in its peaceful coexistence with nature. A sound development of rural community depends largely on healthy people and successful farm income through the hard work in the field by team work of the farmers' family members. Each individual farm should observe the righteous way of farm operation must follow closely with the principle of co-existence of natural environment and wisely use the natural resource without hesitation. Soil and water conservation must be fully observed all the time. Sustainable agriculture alone could hardly reach a successful rural development. Some sort of joint efforts is eventually required. In addition to the importance of supplying adequate water resources through reforestation, other infrastructure, such as financing, marketing, social education, transportation, information, etc., also needs careful planning. Strategic support of the government is especially important to successful rural development. It is true to every nation. Finally, this international symposium will mark a milestone of beginning the scientific approach of the improvement and application of an ancient art in farming, the sustainable agriculture. It is very desirable to propose that this symposium is able to create a world center of communication for the exchange of information concerning sustainable agriculture among members of participating countries for the purpose of technical cooperation among them in the years to come. 

68  Zadoks-J-C  The costs of change in plant protection.  Journal of Plant Protection in the Tropics,  (1992)  9 (2): 151-159,  [En].  Dep. Plant Pathol., Wageningen Agric. Univ., P.O. Box 8025, 6700 EE Wageningen, NET 

Plant protection is in a state of change since ideas on 'integrated' and 'sustainable' agriculture have captivated the general public. Objections against chemical plant protection are increasing. The externalities of crop protection must be considered in economic analyses of plant protection. Politicians begin to take these objections seriously and governments are under pressure to initiate change. The mission of plant protection will be to change radically from present practices with a high level of externalities to new practices in accordance with sustainability criteria. The transition of intensive chemical crop protection in Integrated Pest Management (IPM) is progressing. What is the price of change? Who should pay the price? These questions are addressed using examples from the Netherlands, the USA, Brazil and Southeast Asia. The change may be costly to the growers in some, and profitable in other cases. The change will be financially neutral for the consumer, and profitable to the tax payer. The change will demand great efforts from the pesticides industry, both financially and research-wise.

69  Dobereiner-J; Urquiaga-S  Soil biology and sustainable agriculture.  Anais da Academia Brasileira de Ciencias, (1992) 64 (SUPPL. 1): 127-133,  [En].  EMBRAPA, Centro Nacional Pesquisa Biologia Solo, 23851-970 Seropedica, Rio Janeiro, BRZ

Among the biological processes in soil, dinitrogen fixation has a key role for the development of sustainable agriculture. This process not only can replace the most expensive fertilizer (up to 70% of fertilizer costs) but also reduces considerably ground water pollution with nitrates because biological nitrogen fixation is self regulated. Grain legumes, as the Brazilian soybean crop can replace N fertilizers in a value above US 2 billion every year. Green manure legumes, besides adding N rich organic matter to the soil can help the use of rock phosphates. N-2 fixing legume trees are one of the most promising alternatives for recuperation of eroded soils in agroforestry systems. The extension of biological nitrogen fixation to cereals and grasses represents a major challenge to soil biology. Sugar cane is able to obtain amounts of N from the atmosphere compare with soybeans and this was attributed to new endophytic bacteria which in contrast to the classical concept of rhizosphere bacteria help to explain the high contributions of biological nitrogen fixation in this system. Similar but lower contributions to the rice crop open possibility of expanding this process to other cereals and forage grasses.

70          Lehman-H; Clark-E-A; Weise-S-F  Clarifying the definition of sustainable agriculture.  Journal of Agricultural and Environmental Ethics, (1992) 6 (2): 127-143, [En].  Dep. Philosophy, Univ. Guelph, Guelph, ON, CAN

71          Kada-R  Issues and perspectives of sustainable agriculture.  Journal of Pesticide Science, (1992) 18(4): S201-S206, [Ja]. Dep. Agric. Forestry Economics, Fac. Agric., Kyoto Univ., Kyoto 606, JAP

72  Crews-T-E  Phosphorus regulation of nitrogen fixation in a traditional Mexican agroecosystem. Biogeochemistry (Dordrecht), (1993) 21 (3): 141-166, [En].  Sect. Ecology Systematics, Cornell Univ., Ithaca, NY 14853, USA

Although nitrogen is considered to be the nutrient that most commonly limits production of natural and managed terrestrial ecosystems, I propose that phosphorus may regulate productivity in many continuously cultivated agroecosystems that do not receive applications of synthetic fertilizers. One way P may limit agroecosystem productivity is by controlling nitrogen fixation of legume crops, thus affecting nitrogen availability in the overall agroecosystem. I tested this hypothesis in two studies by examining the effect of phosphorus nutrition on nitrogen fixation of alfalfa in traditional Mexican agroecosystems. All farms used in the research relied on alfalfa as the primary nitrogen source for maize cultivation and other crops, and had minimal or no reliance on synthetic fertilizers. In one study, I used the natural abundance of 15N to estimate nitrogen fixation in five alfalfa plots with soils representing a wide range of P fertility. I found a correlation of r = 0.85 between foliage P concentrations and nitrogen fixation in the alfalfa plots. Mean nitrogen fixation in alfalfa plots ranged between 232-555 kg ha-1 yr-1 as estimated by the 15N-natural abundance method. In a second study, I sampled soils from alfalfa plots on traditional farms located in 5 different physiographic regions of Mexico. Half of each soil sample was augmented with phosphorus in a greenhouse experiment. I grew alfalfa on the fertilized and unfertilized soils from each site and then determined nitrogenase activity (acetylene reduction) of the Rhizobium on the plant roots. Nitrogenase activity increased in the alfalfa grown on all soils with added phosphorus, with two of the five differences being statistically significant at P lt 0.01, and one at P lt 0.05. Foliage P concentrations and nitrogenase activity were positively correlated (r = 0.81, P lt 0.01). 

73  Banuelos-G-S; Cardon-G; Mackey-B; Ben-Asher-J; Wu-L; Beuselinck-P; Akohoue-S; Zambrzuski-S  Boron and selenium removal in boron-laden soils by four sprinkler irrigated plant species.  Journal of Environmental Quality, (1993) 22  (4): 786-792, [En].  UDSA-ARS Water Management Res. Lab., 2021 S. Peach Ave., Fresno, CA 93727, USA

High concentrations of B and Se found in some arid environments are detrimental to sustainable agriculture. Vegetation management may be a remediation strategy designed to reduce soil B and Se concentrations to nontoxic levels. Two separate field experiments were conducted to study B and Se uptake in four different plant species grown in soil containing high concentrations of B (water-extractable B ranging from 1-10 mg kg-1 soil) and Se (total soil Se ranging from 0.1-1.2 mg kg-1 soil). The four species were Brassica juncea L. Czern and Coss (Indian mustard), Festuca arundinacea Schreb cv. Fawn (tall fescue), Lotus corniculatus L. (birdsfoot trefoil), and Hibiscus cannibinus L. (kenaf). In the 1990 experiment, there were no differences in either tissue B or Se concentrations among the species. The mean tissue concentration was 105 mg B kg-1 dry matter (DM) and 0.75 mg Se kg-1 DM, respectively. In the 1991 experiment, mean shoot tissue concentrations of B ranged from a low of 96 mg kg-1 DM in tall fescue to a high of 684 mg B kg-1 DM in leaves from kenaf. Indian mustard accumulated the greatest amount of Se (gt 1 mg Se kg-1 DM), while the mean tissue concentration among the other three species was 0.36 mg Se kg-1 DM. For both experiments, soil samples were taken prior to planting and after harvest for each species to a depth of 0 to 30 and 30 to 60 cm, and analyzed for water-extractable B and total Se. Summary data from all species indicated that extractable soil B and total Se concentrations were reduced between 0- to 60-cm soil depth by 52 and 48% in 1990, and by 24 and 13% in 1991, respectively. Planting any of the four species tested in B-laden soils may lead to a reduction in both B and Se concentrations in the soil.

74  Hatfield-J-L  Sustainable agriculture: Impacts on nonpoint pollution.  Water Science and Technology, (1993) 28 (3-5): 415-424, [En]. USDA-ARS, Natl. Soil Tilth Lab., 2150 Pammel Drive, Ames, IA 50011-4419, USA

76    Francis-C-A; Madden-J-P Designing the future: Sustainable agriculture in the US.Agriculture Ecosystems & Environment, (1993) 46(1-4): 123-134, [En]. Univ. Nebr., Lincoln, NE 68583-0910, USA

Global agriculture is entering a challenging and difficult period with an increasing human population and an accelerating need for food, fiber, feed, and raw materials for other industries. This challenge will need to be met on fewer hectares of available land and a reduced supply of the fossil fuel inputs that have catalyzed the increased productivity of the past five decades. Agriculture in some forms has negative and lasting effects on the environment. The research and education community is seeking a more resource-efficient, sustainable system of food production that has less negative impact on the environment. This system is characterized by increased resource use efficiency, greater reliance on internal or renewable resources, increased short- and long-term profitability, enhancement of soil productivity, minimal negative environmental impact, and social viability for families and communities. Agricultural research over the last half century has contributed many components to sustainable productivity, but its focus in the future will be more on systems, interactions among components, and the impact of the activity on the broader environment and community. Education in agriculture is moving from a concentration on memorizing detail and cook-book approaches to a development of creative thinking and problem solving skills. We are building the capacity to access and apply a wide range of information resources. There is a growing congruence of classroom teaching and adult education in extension, an evolution that will lead to better curriculum planning for a life-long educational and learning experience. All the key players in US agriculture will take greater responsibility for their own learning in this system, being empowered to conduct both on-station and on-farm research, design learning activities, and evaluate progress and applications of information to real world challenges. This paper describes what is happening in the US in research, in teaching, and in extension. We also envision a new paradigm for education in the future. Instead of preparing to react or adjust to a predictable future, an empowered rural populace can begin to design a more desirable future. With increased focus on scarce resources, fragility of the environment, and the lessons of nature, we can take creative approaches to systems design and begin to make decisions today to create a more sustainable future for tomorrow.

77  Ikerd-J-E  The need for a systems approach to sustainable agriculture.  Agriculture Ecosystems & Environment, (1993) 46 (1-4): 147-160,  [En].  Cent. Sustainable Agric., Univ. Mo.-Columbus, MO 65211, USA

Differences between conventional and sustainable paradigms of agriculture are much more a matter of differences in farming philosophy than of farming practices or methods. The conventional model of agriculture is fundamentally an industrial development model which views farms as factories and considers fields, plants, and animals as production units. The goal of industrial development is to increase human well-being by increasing production of material goods and services and simultaneously increasing aggregate employment and incomes. The underlying assumption of the industrial model is that a higher quality of life can be derived from increases in income and consumption of goods and services. A fundamental strategy for industrial development has been to specialize, routinize, and mechanize agricultural production in order to achieve the economic efficiencies that are inherent in large-scale industrial production. New technologies are designed to remove physical and biological constraints to production and, thus, make unlimited progress possible. Sustainable agriculture, on the other hand, is based on a holistic paradigm or model of development which views production units as organisms that consist of many complex interrelated suborganisms, all of which have distinct physical, biological, and social limits. People are viewed as part of the organisms or systems from which they derive their well-being. Quality of life is considered to be a consequence of interrelationships among people and between people and the other physical and biological elements of their environment. Fundamental strategies for sustainable development include diversification, integration, and synthesis. Whole systems have qualities and characteristics that are not contained in their individual parts or components. The same set of components or pans may be rearranged spatially or sequentially resulting in a unique system or whole for each new arrangement. People increase their well-being by using information and knowledge to manage or rearrange the components of systems, resources, processes, and technologies in ways that enhance the productivity or 'well-being' of those systems. Human progress is limited only by our ability to enhance the social, biological, and physical systems of which we are a part. Sustainable agriculture requires a holistic systems approach to farm resource management. A component approach focusing on individual farming practices, methods, and enterprises may have been appropriate for the era of agricultural industrialization. However, a systems approach which focuses on knowledge-based develeconomic, and social challenges of the post-industrial era of agricultural sustainability.

78  Buttel-F-H  The sociology of agricultural sustainability: Some observations on the future of sustainable agriculture.  Agriculture Ecosystems & Environment, (1993)  46 (1-4): 175-186,  [En]. Dep. Rural Sociol., Univ. Wis., Madison, WI 53706, USA 

It is argued that sociology and the other social sciences can contribute to agricultural sustainability in several ways, one of which is to help in assessing and understanding the social forces that affect agricultural research and agricultural policy. Many of the conditions that gave rise to expansion of sustainable agriculture in the 1980s are changing, and sustainable agriculture faces several fiscal and political vulnerabilities. A typology of sustainable agriculture research is developed to illustrate the point that scientists and proponents of sustainable agriculture can help to address these vulnerabilities by deversifying their approaches to developing environmentally sound agricultural technologies.

79  Altieri-M-A Ethnoscience and biodiversity: Key elements in the design of sustainable pest management systems for small farmers in developing countries.  Agriculture Ecosystems & Environment, (1993)  46 (1-4): 257-272, [En]. Div. Biol. Control, Univ. Calif. Berkeley, 1050 San Pablo Ave., Albany, CA 94706, USA

Biodiversity is a salient feature of traditional farming systems in developing countries and performs a variety of renewal processes and ecological services in agroecosystems. It is of fundamental importance to understand the role biodiversity can play in reducing pest problems, if vegetation management is to be used effectively as a primary IPM tactic in small-scale sustainable agriculture. The maintenance of biodiversity in traditional agroecosystems is not random, but depends on a complex set of indigenous technical knowledge systems (ethnoscience). Thus, the ensemble of traditional crop protection practices used by indigenous farmers represents a rich resource for modern workers seeking to create IPM systems that are well adapted to the agroecological, cultural and socio-economic circumstances facing small farmers throughout the developing world.

80  Schaller-N  The concept of agricultural sustainability. Agriculture Ecosystems & Environment,  (1993) 46 (1-4): 89-97,  [En].  Inst. Alternative Agric., 9200 Edmonston Road, Suite 117, Greenbelt, MD 20770, USA

Sustainable agriculture has become a popular code word for an environmentally sound, productive, economically viable, and socially desirable agriculture. This paper reviews reasons for growing interest in agricultural sustainability (mainly the unanticipated, adverse side-effects of conventional farming), examines the proposed ends and means of sustainability, and discusses two issues frequently debated - the profitability of sustainable farming and the adequacy of food production from sustainable systems. The concept of agricultural sustainability does not lend itself to precise definition, partly because it implies a way of thinking as well as of using farming practices, and because the latter cannot be specified as final answers. Consequently, people's beliefs and values will continue to mold public understanding of the concept. Two different views of sustainable agriculture are held. One is that fine- tuning of conventional agriculture - more careful and efficient farming with sensitive technologies - will reduce or eliminate many undesirable effects of conventional agriculture. The other is that fundamental changes in agriculture are needed, requiring a major transformation of societal values. Those who believe that only fine-tuning is needed tend to argue that sustainable farming is inherently unprofitable. If widely adopted, it would not feed the world's expanding population as well as conventional agriculture. Those who see a need for more fundamental changes in conventional systems believe that sustainable farming, on the contrary, can be even more profitable than the conventional, especially when the calculation of profit counts all of the benefits and costs of farming. Further, resource conservation, protection of the environment, and farming in partnership with nature - all requirements of sustainability - will enhance, not reduce, global food production. Other issues, such as the connections between sustainable farming and the rest of the food and fiber system, and the implications of sustainability for rural communities and society as a whole, have yet to be addressed significantly.

81  Ajwa-H-A; Tabatabai-M-A  Decomposition of different organic materials in soils.  Biology and Fertility of Soils (1994) 18 (3): 175-182  [En.] Dep. Agronomy, Iowa State Univ., Ames, IA 50011, USA

Laboratory experiments were conducted to evaluate organic C mineralization of various organic materials added to soils. A soil sample was mixed with organic material to approximate a field application of 9 g organic C kg-1 soil (0.9% or 50 Mg ha-1). The organic materials used were four crop residues (corn (Zea mays L.), soybean (Glycine max L. Merr.), sorghum (Sorghum vulgare Pers.), and alfalfa (Medicago sativa L.)), four animal manures (chicken (Gallus domesticus), pig (Sus scrofa), horse (Equus caballus), and cow (Bos taurus)) and four sewage sludges (Correctionville (Imhoff tank), Charles City (holding tank), Davenport (secondary digester), and Keokuk (primary digester)). The soil-organic material mixture was incubated under aerobic conditions at room temperature (20+-2 degree C) for 30 days. The CO₂ evolved was collected in standard KOH solution by continuously passing CO-2-free air over the soil. Results showed that, in general, the amounts of CO-2-C released increased rapidly initially, but the pattern differed among the organic materials used. More than 50% of the total CO-2 produced in 30 days of incubation was evolved in the first 6 days. Expressed as percentages of organic C added, the amounts of CO₂ evolved ranged from 27% with corn to 580% with alfalfa. The corresponding percentages for animal manures ranged from 21 to 62% with horse and pig manures, respectively, and for sewage sludges they ranged from 10 to 39% for Charles City and Keokuk sludges. All CO₂ evolution data conformed well to a first-order kinetic model. Potentially, readily mineralizable organic C values and first-order rate constants (k) of the organic matter-treated soils ranged from 1.422 g C kg-1 soil with a k value of 0.0784 day-1 to 6.253 g C kg-1 soil with a k value of 0.0300 day-1. The half-lives of the C remaining in soils ranged from 39 to 54 days for plant materials. The corresponding half-lives for the C remaining from animal manures and sewage sludges ranged from 37 to 169 days and from 39 to 330 days, respectively.

82  Alain-A  Biological agriculture and sustainable development.  Medecin Veterinaire du Quebec (1994) (SPEC. ISSUE): 51-52, [Fr.] Ministere l'Agriculture, l'Alimentation Pecheries Que., 298 Boul. Theriault, 3e etage, Riviere-du-Loup, PQ G5R 4C2, CAN 

Because of his agricultural practices, man has transformed and exploited nature. We are confronted with important problems at the soils levels, landscape transformation, and water contamination. We have to include in our criteria of success the concept of sustainability. The veterinarian with a preventive medicine approach can play an important role for sustainability in agriculture. He has to be an integral partner of an holistic approach in agriculture.

83  Dick-R-P; Sandor-J-A; Eash-N-S  Soil enzyme activities after 1500 years of terrace agriculture in the Colca Valley, Peru. Agriculture Ecosystems & Environment (1994) 50 (2): 123-131, [En.]  Dep. Crop Soil Sci., 3017 Agricultural Life Sci. Build., Oregon State Univ., Corvallis, OR 97331, USA 

Long-term productivity and conservation of soils is critical for sustaining agricultural ecosystems. Long-term sites can provide important information about the effects of soil management practices on soil properties but there are relatively few such sites available worldwide. The Colca Valley of Peru provided a unique opportunity to study the effects of 1500 years of cultivation on Mollisols. The specific objective of the work reported was to determine the effects of cultivation at this site on soil enzyme activity as an index of soil biology and biochemistry. The study compared three key soil enzyme activities (phosphatase, beta-glucosidase, and amidase) in presently cultivated and abandoned agricultural terraces, and matched uncultivated soils. Results showed that levels of organic matter, nitrogen and phosphorus were greater in agricultural than uncultivated soils. Unlike temperate regions where monoculture, intensive tillage and/or inorganic fertilizer practices have depressed soil enzyme activities, cultivated Colca soils have maintained similar or higher activities than the uncultivated/native soils. Maintenance of enzyme activities over hundreds of years in agricultural soils is partly attributed to traditional management practices including rotations with legumes, additions of animal manures, and minimum tillage.

84  Donald-A-D  Parasites, animal production and sustainable development.  Veterinary Parasitology (1994), 54(1-3): 27-47, [En.] Inst. Anim. Production Processing, CSIRO, P.O. Box 93, North Ryde, NSW 2113, AUL 

Ecologically sustainable development is aimed at reducing environmental degradation while enabling economic development with equity between the developed and developing worlds and between generations. Parasite control in livestock can both contribute to, and take advantage of, sustainable agriculture. This will tend towards less intensive, lower input, diversified crop and animal production with less risk of parasite-induced losses and greater opportunities for integrated control including the exploitation of grazing management. Chemotherapy will continue to play a part but the most serious problem is resistance in the target species. Except for a few isolated issues, currently used parasiticides are relatively minor contaminants of the food supply or the environment. Nevertheless, the compounds of the future will need to be narrow-spectrum, non-persistent and rapidly degraded, with convenience in the hands of the user reduced in importance. Environmentally friendly alternatives to chemotherapy, including genetic resistance of hosts, vaccines, and biological control, show considerable promise and must be pursued. Sustainable systems pose optimization problems and more attention must be given to systems research, models and products to aid decisions. If governments are serious about sustainable development, greater support will be needed for longer-term patient, multi-disciplinary research.

85  Bugg-R-L; Waddington-C  Using cover crops to manage arthropod pests of orchards: A review.  Agriculture Ecosystems & Environment (1994), 50 (1): 11-28, [En.] Information Group, Sustainable Agriculture Res. Education Program, Univ. Calif., Davis, CA 95616-8533, USA

A review of entomological studies of cover crops for tree nuts, pome fruits, stone fruits, and citrus suggests both opportunities and challenges. Various cover crops harbor distinctive complexes of beneficial and pest arthropods, and diverse trophic relationships have been well documented in the literature. More study is required to determine: (1) whether cover cropping modifies orchard microclimate and target crop nutritional status and thereby influences pest dynamics; (2) whether and how cover crop species composition, spatial interspersion of species, and management by irrigation, mowing, and tillage affect build-up and movement of arthropods, and resultant pest damage to the target crop.

86  Beese-F; Hartmann-A; Beck-T; Rackwitz-R; Zelles-L  Microbial community structure and activity in agricultural soils under different management.  Zeitschrift fuer Pflanzenernaehrung und Bodenkunde  157 (3): 187-195, [En.] GSF-Forschungszentrum Umwelt Gesundheit, Inst. Bodenoekologie, Neuherberg, Ingolstaedter Landstr. 1, D-85758 Oberschleissheim, GER 

For the development of management strategies in sustainable agriculture it is necessary to describe and predict the role of soil microbes in different management systems. The classical approach uses the microbial biomass as the key parameter for the entire system, but for ecological purposes the variability of biotic parameters in time and space has to be better described. Moreover, the biomass active in the total soil profile or its most active zones should be used as a basis for the assessment of soil activity. The sum of adenylates was found to be more closely related to the microbial biomass than was ATP, which however appeared to be a better indicator for the microbial activity. Fatty acids from phospholipids were highly correlated with the soil microbial biomass. The pattern of fatty acids from soils under different long-term management indicated a high potential to typify the microbial community in soils and special organism populations. To overcome the problem, that only a small portion of the soil inhabiting microbes can be cultivated, first steps to use serological and genetical methods to directly identify or localize specific populations in the rhizosphere are shown.

87  Kim-K-C  Entomology in the changing world: Biodiversity and sustainable agriculture.  Korean Journal of Entomology (1994), 24 (2): 145-153, [En.] Dep. Entomol., Frost Entomological Museum, Center BioDiversity Research, ERRI, Pennsylvania State Univ., University Park, PA 16802, USA

For the last hundred years technological society has brought us a material wealth, healthier and longer life, and the information age. Along with it, however, human population has increased rapidly with dramatic changes in the population structure, and the world environment has greatly deteriorated. The issues and problems associated with these changes require new interdisciplinary approaches for long-term solution. Entomology certainly is among the important aspects of the problem-solving strategy. Over a century entomology as science and a scientific discipline has made significant contributions to the exploration of global biodiversity and population management of agricultural pests and disease vectors. Similarly, major advances have been made in morphology, taxonomy, ecology, physiology, and other aspects of insect biology. In the process many of these entomological disciplines have become highly specialized and independent, often losing their affinity and relevance to each other. Current societal problems demand a close collaboration and interdisciplinarity. This paper elaborates my thoughts on the recent trends of entomology in relation to the rapid changes taking place in our world and the role we the entomologists should play in diverting the technological tendency from the destructive path and building toward a sustainable society, the sustainable life-support system, where we can live in clean environment with the riches of biodiversity while enjoying the benefits of technological society. Among the most urgent and pressing issues are the loss of biodiversity and habitat fragmentation, genetic variation of pest populations related to integrated pest management, low-input and sustainable agriculture, and entomological problems emerging in rapidly expanding urban environment. Some recommendations are made for advancing these crucial areas of entomology.

88  Olsen-P-E; Rice-W-A; Bordeleau-L-M; Biederbeck-V-O  Analysis and regulation of legume inoculants in Canada: The need for an increase in standards.  Plant and Soil (1994), 161 (1): 127-134, [En.]  Agric. Can., Beaverlodge, AB, CAN 

Rhizobial inoculants for use in Canada are regulated and have been evaluated in a formal testing program since 1975. This program is carried out by Agriculture Canada under authority of the Fertilizers Act and involves inoculant strain and formulation registration (with Food Production and Inspection Branch) as well as analysis (by Research Branch) of approximately 220 inoculants and pre-inoculated seed products yearly. Inoculant evaluation is based upon the calculated number of viable rhizobia which would be provided per seed if the inoculant was applied at the manufacturer's recommended rate. Current standards are 10-3, 10-4, and 10-5 viable rhizobia per seed, of the proper cross-inoculation group, for small, intermediate, and large seeded legumes, respectively. Application of these standards means that some inoculants are considered "satisfactory" even though they yield test results as low as 9.4 times 10-6 rhizobia per gram. No standards are currently applied relative to permissible levels of contaminants in inoculant products, despite the fact that some inoculants contain many more contaminating microorganisms than they do Rhizobium cells. The demands of modern sustainable agriculture, taken together with advances in inoculant formulation technology, warrant an increase by a factor of ten in the minimum acceptable Canadian standards for legume inoculants and pre-inoculated seed products.

89       Heinloth-K; Karimanzira-R-P  Outcomes and policy recommendations from the IPCC/AFOS working group on climate change response strategies and emission reductions.  Climatic Change  (1994), 27 (1): 139-146, [En.] Physikalisches Inst., Univ. Bonn, Nussallee 12, D-5300 Bonn 1, GER

90  Yunlong-C; Smit-B  Sustainability in agriculture: A general review.  Agriculture Ecosystems & Environment (1994), 49(3): 299-307, [En.] Dep. Geography, Peking University, Beijing 100871, CHN 

This paper presents a framework within which the sustainability of agricultural systems can be assessed. The model recognizes biophysical, socio-political and techno-economic dimensions of agriculture and its sustainability, and distinguishes spatial scales, from the field to the globe, at which agricultural sustainability can be considered. Each theme implies a different emphasis and a distinct set of analytical questions. Sustainable agriculture should combine all the components of 'sound husbandry' into a united package. 

91  Mitchell-A  Researchers go to the farm: Scientists take experiments to the people.  Agroborealis  (1994) 26 (1): 6-8, [En.] Agric. and Forestry Exp. Stn., P.O. Box 757200, Fairbanks, AK 99775-7200, USA 

92  Wilson-T-M-A; Davies-J-W  New roads to crop protection against viruses.  Outlook on Agriculture (1994) 23(1): 33-39,[En.]  Scottish Crop Res. Inst., Invergowrie, Dundee DD2 5DA, UK

93  Wyse-D-L  New technologies and approaches for weed management in sustainable agriculture systems.  Weed Technology (1994) 8 (2): 403-407, [En.] Dep. Agron. Plant Genetics, Univ. Minnesota, St. Paul, MN 55108, USA 

Weed science has a long history of solving weed management problems for farmers. Over the last four decades most of the solutions to weed problems have been based on herbicide technology. Thus, most crop production systems in the United States rely heavily on herbicides as the primary method of weed management. During the last decade environmentalists, farmers, agricultural scientists, policy makers, and the general public have begun to question the long-term sustainability of conventional farming systems. The sustainability of these systems is being questioned because of environmental, social, and economic concerns caused by global competition, cost of production, soil erosion, water pollution, and concern over the quality of rural life. Weeds are the major deterrent to the development of more sustainable agriculture systems. Since weeds dictate most of the crop production practices (e.g., tillage, herbicides, cultivation, row spacing) weed scientists must become the leaders of collaborative integrated approaches to agriculture systems research. New crop production systems must be developed that are less destructive to the environment, are profitable, conserve energy, and support rural community development. The goal is to facilitate the development of ecologically based alternative methods of weed management that will support crop production systems that require less tillage and herbicide inputs. To accomplish this goal, research efforts must be radically expanded in weed/crop ecology and in the development of ecologically based technologies for weed management.

94  Williams-B-L; Bennison-L; Pascoe-I-G  The effect of Stagonospora foliicola on Phalaris aquatica under glasshouse conditions. Australasian Plant Pathology (1994) 23 (1): 16-19, [En.]  Inst. Sustainable Agriculture, RMB 3031, Cooma Road, Kyabram, Victoria 3630

The phalaris cultivars Australian and Sirosa, artificially inoculated under glasshouse conditions, were found to be susceptible to infection by Stagonospora foliicola. Diseased plants had significantly higher numbers of dead leaves than healthy plants. However, dry matter yields of tops and roots, and average leaf and tiller numbers of diseased and healthy plants were not significantly different.

95  Joo-P-K  Agriculture in North Korea, I Saw: Emphasis on horticulture and field corn.  Journal of the Korean Society for Horticultural Science (1994) 35 (SUPPL.): 6-21, [En.] Agglobe Technol., Minneapolis, MN, USA

This paper does not intend to claim that the author understands the system and productivity of North Korean Agriculture very well. During several limited travels to the agricultural institutions and rural communities of North Korea, The Democratic People's Republic of Korea (DPRK), the author observed that there has been tremendous efforts driven to be self-sufficient through sustainable agriculture under very limited resources. Although 80% of the rugged mountain range, in the country do not allow much space to convert into large cultivable fields, painstaking efforts have been made for arable land increment program through terrace farming on the hills and massive western seaboard land reclamation programs since 1954. Remarkable achievement is claimed in irrigation system throughout the country. However, continental weather with Siberian wind across the high altitude creates many unfavorable microclimatic conditions and cold stresses throughout the northern half of the Korean peninsula located between 38 degrees and 43 degrees North. Many years of isolation from the West resulted in greatly limited economic cooperation with and advanced technology transfers from the economically developed world. The mechanization of agriculture and cultivar improvement has, therefore, been substantially limited for all their efforts to improve with their own resources. Breeding effort in major staple food grain (rice and maize) appears to be enormous. Breeding of cold and salt tolerant early rice varieties yielding over 10 MT/ha is the national slogan. According to the records, the national average yield of rice is 6.5-7.0 MT/ha and recently the record high of 13 MT/ha has been claimed to be achieved with a new variety in experimental plots. Improvement for maize yield was attained by hybridization and early planting. North Korea may be the only Asian country who cultivates 100% hybrid maize and is also transplanting maize seedlings to overcome the short growing season. Breeding goals for maize are cold tolerance, short stature plant with strong stark quality and early maturity along with other traits such as high density planting, and disease and insect tolerances. Due to such effort they have been successfully cultivating 130-135 day maturity hybrids up to 40 degree N and reduced wind damage from typhoon. All maize fields observed alongside of highway from Pyungyang to Haeju and Pyungyang to Wonsan were very uniform in heights which might be the indication of genetic purity of seed lots. It was claimed that the yield of maize were 7 MT/ha in national average, and record high of 13 MT/ha was achi released this year is expected to yield 15 MT/ha. Some hybrids have western germplasm background which were introduced through former Yugoslavia. Main vegetable crops are cabbage (Brassica olerasia L. var. capitata), chinese cabbage (Brassica compastris var. pekinensis), radish. spinach and chili pepper. Among these crops, cabbages (B. oleracea) and spinach are claimed to have very good hybrids. Major portion of vegetables is produced as preplanting and post-harvest crop of rice and maize as well as full season crop. All above vegetables except spinach and radish appear to be transplanted. Multicropping and high density planting on a unit area have been the important part of the effective land utilization. Vegetable production in glass and polyethylene greenhouses and polyethylene tunnels appear to be growing very fast. Large scale orchards, industrial crop production, sericulture, and livestock especially, swine and poultry production programs are also emphasized in the adaptable areas. Many exotic plant germplasms, especially medicinal plants and wild edible plants are well researched. DPRK joined in IBPGR in 1986 seeking assistance from FAO to expand present gene bank in North Korea. The most important input for North Korea from the West and developed Asian countries with similar climatic conditions appear to be elite germplasm exchange, agricultural supplies, advanced technologies and efficient farm machineries. Very good work ethics and relatively high basic educational level of work force could contribute to very fast progress in economic development and agricultural productivity with benefit of financial and technological input as well as genetic resources exchange. Based on the candid observations and information obtained through personal contacts and published papers from the North and South Korea, author finds great opportunity to complement each other for agricultural economics development in the North and the South. Author would like to see the development of cooperation and exchange in agricultural technology and genetic resources. An assistance from the agricultural sector of the United States and Western Europe, as well as from all the other developed countries could be of great contribution to the economic progress of North Korea. 

96  Loker-W-M  Where's the beef?: Incorporating cattle into sustainable agroforestry systems in the Amazon Basin.  Agroforestry Systems (1994) 25 (3): 227-241, [En.]  Dep. Sociol., Anthropol. Social Work, Mississippi State Univ., Mississippi State, MS 39762, USA 

Low external input agroforestry systems hold great promise as alternative, sustainable production systems for small-to-medium farmers in the Amazon Basin. The design of such systems is considered essential to stabilize agricultural production and avoid the cycle of continuing destruction of primary forest (Anderson A (1990) In: Anderson A (ed) Alternatives to Deforestation: Steps toward Sustainable Use of the Amazon Rain Forest pp 3-23. Columbia University Press, New York). In order to be successful, these systems must be compatible with local ecological conditions and adoptable by farmers. Currently, many small-to-medium producers in the Amazon Basin use a slash and burn agricultural strategy that combines annual cropping with cattle grazing in mixed farming systems. While cattle play an important role in household economic survival, grazing-induced land degradation threatens the long-term viability of these farms (Loker W (1993) Human Organization 52 (1): 14-24). This paper presents a model of a low external input agroforestry system that incorporates farmer preferences and practices but uses well-adapted grass-legume pastures, rotational grazing and the management of natural forest regeneration to enhance productivity in an ecologically sound manner. This system provides farmers with the benefits of both annual crops and cattle raising, avoids the land degradation that characterizes current practices and effectively incorporates trees into the production system.

97  Rajan-S-S-S; O'Connor-M-B; Sinclair-A-G  Partially acidulated phosphate rocks: Controlled release phosphorus fertilizers for more sustainable agriculture.  Fertilizer Research (1994) 37 (1): 69-78, [En.]  AgRes., Ruakura Agric. Centre, Private Bag 3123, Hamilton, NEZ 

Phosphate rocks partially acidulated either with H₃PO₄ or H₂SO₄ were compared against SSP or TSP as phosphate fertilizers for permanent pasture. Eleven field trials were conducted over periods of up to 6 yrs. Fertilizers were surface applied annually. Initial soil pHw values ranged from 5.5-6.3 and Soil P retention from 25% to 97%. The PRs used for partial acidulation were unground or ground North Carolina PR, ground Khouribga PR, and a blend of ground PRs of North Carolina, Arad and Khouribga PRs. From the DM yields, fertilizer substitution values were calculated: fertilizer substitution value was the ratio of total P applied as superphosphate to total P as PAPR required to produce the same DM yield. Rates of dissolution of the PR component of PAPRs were also determined in soils collected from two trials. Agronomic results demonstrated that 30% acidulated phosphoric PAPRs (about 50% of total P as water-soluble P) were as effective as TSP, when the PR acidulated was from unground North Carolina PR. Results from one field trial indicated that when PAPR was from ground North Carolina PR, 20% acidulated product (water-soluble P 30-40% of total P) was equally effective as TSP. Replacement of ground North Carolina PR by a less reactive Khouribga PR did not appear to decrease the yield. Results indicated that per unit P released into soil solution, PAPRs were more efficient fertilizers than TSP. With annual applications, fertilizer substitution value of PAPR 30% tended to increase with time. Sulphuric PAPRs prepared from North Carolina PR were generally inferior to phosphoric PAPRs containing similar amounts of water-soluble P. This was attributed to the presence of CaSO₄ coatings. 

98  Lauren-J-G; Pettygrove-G-S; Duxbury-J-M  Methane emissions associated with a green manure amendment to flooded rice in California.  Biogeochemistry (Dordrecht) (1994) 24 (2): 53-65, [En.] Soil Crop Atmospheric Sciences Dep., Bradfield Hall, Cornell Univ., Ithaca, NY 14853, USA 

The goals of sustainable food production and mitigation of greenhouse gas emissions may be in conflict when green manures are used in flooded rice systems. A field study was initiated in early spring 1992 near Sacramento, California to quantify the potential for enhanced methane emissions following a green manure amendment to rice. Replicate flux measurements were made twice a day every 3-4 days throughout the growing season in four treatment plots: burned rice straw, spring incorporated rice straw, burned straw plus purple vetch and spring incorporated straw plus vetch. Seasonal methane emissions ranged from 66-136 g CH₄ m-2 and were 1.5 to 1.8 times higher from the straw plus vetch treatments relative to the straw only treatments. No significant differences in emissions were found between the two straw only treatments or the straw plus vetch treatments. Methane fluxes were exponentially related to soil temperature, but no effect of redox potential or floodwater depth were observed. The potential impact of these results on the global methane budget is discussed.

99  Sakai-K; Takai-M; Nakashima-H; Kawai-T; Satoh-H; Nakano-H; Hashimoto-T; Aoki-H; Sugiyama-S  Implications of heavily mechanized farming on field operation: Case study for experimental farm of Hokkaido University.  Journal of the Faculty of Agriculture Hokkaido University (1994) 66 (1): 69-77, [En.]  Lab. Crop Prod. Eng., Fac. Agric., Hokkaido Univ., Sapporo 060, JAP

100  Voland-R-P; Epstein-A-H Development of suppressiveness to diseases caused by Rhizoctonia solani in soils amended with composted and noncomposted manure.  Plant Disease (1994) 78(5): 461-466, [En.] Dep. Horticulture, Univ. Wisconsin-Madison, Madison, WI 53706, USA

Fresh and composted dairy manure were compared along with other amendments in the greenhouse and in field microplots for their effects on induction of suppression to plant diseases caused by Rhizoctonia solani. Damping-off of radish induced by R. solani was least severe for seedlings planted in the greenhouse in soil media amended with urea and straw, more severe with manure or compost, and most severe after urea treatment. Radish damping-off was less severe at all inoculum density levels in the urea with straw treatment than in the other amendment treatments. At very high infestation levels (20 and 30 cfu/g R. solani), disease severity did not differ among the least effective amendments. The population of R. solani did not differ among treatments, despite differences in radish damping-off severity. Manure and compost were more effective than urea alone in inducing suppression of damping-off of radish at low inoculum levels. Neither amendment was effective at high inoculum levels. Bean hypocotyl lesions were least common for seedlings planted in field microplots amended with manure, and more severe in those treated with compost. Composting of animal manure did not significantly enhance the effectiveness of manure for inducing suppression in soil of plant diseases caused by R. solani.