Conservation tillage (CS) is used widely in rainfed and sprinkler-irrigated production systems but adoption of CS on furrow-irrigated cropland has been limited. Some crops and crop rotations are more conducive to conservation tillage under furrow irrigation than others. The objective of this research was to evaluate CS in a furrowirrigated crop rotation of corn, soybean, winter barley, and dry bean at Fruita, Colorado in 1991 and 1992. Infiltration rates were 24 and 50% higher and advance times were 37 and 25% longer in the CS treatment during 1991 and 1992, respectively, compared with conventional tillage (CV). Furrows in the CV treatment were 8 and 25% wider than those in the CS treatment after the first and sixth irrigations, respectively. This indicates more soil movement with CV than with CS. In 1992, soil water content in the CS treatment was 17, 17, and 27% higher than with CV throughout the growing season for corn, soybean, and dry bean, respectively. Grain yields of winter barley, soybean, dry bean, and corn were not affected significantly by tillage treatment. Profitability of CS and CV was quite similar when all four crops in the rotation were considered together. This research was conducted under conditions expected to be similar to those that could be used by growers and indicates that corn, soybean, winter barley, and dry bean can be grown successfully in rotation using conservation tillage under furrowirrigated conditions. Successful adoption of conservation tillage under furrow irrigation will require growers to adopt encompassing new production management practices and possibly purchase new equipment such as planters and cultivators that will operate in high residue conditions, and growers must overcome any psychological barriers they may have to maintaining high amounts of surface crop residue when furrow irrigating.

Agricultural research and education significantly influence the direction of U.S. agriculture by improving the practices available to farmers and by decreasing uncertainties associated with adopting new farming practices. Because sustainable agriculture is management-intensive, access to information is particularly important in adopting and implementing sustainable farming practices. Given that relatively little funding is allocated to sustainable agriculture research by the federal government, successful dissemination of these research results is critical. This paper presents an analysis of the dissemination efforts of 42 researchers funded through the USDA's North Central Region Sustainable Agriculture Research and Education (SARE) program. Results show that these SARE researchers purposefully consider the effectiveness of various dissemination methods in reaching targeted audiences and attempt to involve farmers in their dissemination efforts. Overall, researchers note that information dissemination is limited by farmer interest. Additional barriers exist, most notably insufficient resources and institutional biases. In the future, the ways in which information is compiled and made available must be improved, and responsibility for farmer outreach should be better coordinated.

The focus of this paper is the challenge to technology development in the international pesticide industry. We address these challenges within the context of debates on how to achieve an environmentally- and economically-sustainable world food production system. Forces acting within and upon both pesticide manufacturers and the agrifood system are moving toward globalization and standardization. Main issues on sustainability in agriculture are protecting and improving agricultural resources (e.g., preserving and restoring soil and water quality). This places greater emphasis on diversity, regional self reliance, reduced chemical dependence and greater community involvement. A small but rapidly growing movement in local food systems is evolving in parallel with globalized agribusiness. It offers new opportunities for private sector development of technologies and services. These opportunities could be interesting for companies that are struggling to retain profitability in a stagnant and commodityoriented pesticide market. Our question is whether the pesticide industry is structurally capable of developing innovations in products and services for these new local/regional markets to ensure a more diversified and sustainable agriculture. Our conclusion is probably not, but if the industry were capable of doing so it would first need to acquire a thorough understanding of how organic farming systems function.

This paper examines what land grant colleges of agriculture were designed to be and do and, using their published mission statements, discusses what they now claim to be and do. Teaching ‘such branches of learning as are related to the agriculture and the mechanic arts’ and ‘to promote the liberal and practical education of the industrial classes’ is what land grant colleges were designed to do; it is the land grant mission. The paper asks whether these things are what land grant colleges of agriculture do now. The original mission has been amended with new challenges that must be met in a time of declining public support for higher education, societal distrust of science and a negative public perception of agricultural technology, in a culture that wants cheap food. The agricultural community, including colleges of agriculture, has been slow to accept the challenges and opportunities inherent in the questions agriculture now faces. Agriculture remains an essential human activity in our post-industrial, information-age society. Colleges of agriculture are in trouble, and this paper suggests that the sensible thing to do may be to turn away from self-interest in survival to take a leadership role with emphasis on the obligations of service and humanism.

The sustainability of farming systems must be assessed by their potential environmental, economic, and social performance. We present a case study to illustrate an assessment of relative sustainability that uses all three performance criteria.

We developed two scenarios for farmland currently enrolled in the Conservation Reserve Program (CRP) in Putnam County, Missouri: a conventional scenario reflecting farming practices typical of northern Missouri, and an alternative that we hypothesize to be more environmentally sound. We used selected economic and social indicators to assess whether the latter would be at least as economically viable and socially responsible as the conventional system.

Estimated direct farm income was $3.4 million for the alternative and $2.4 million for the conventional scenario. The alternative system applies more labor and management to a given land resource and may support more farming families. Estimated total community economic impacts were 25% greater for the alternative than the conventional farming scenario. CRP land, therefore, could be returned to production in a way that could significantly enhance local economic and social benefits while retaining many of the CRP's environmental benefits.

The scale of operation and economic performance of organic and conventional dairy farms were compared in Ontario in 1992. Eight certified organic (ORG) farms, comprising 40% of all organic dairy farms, were contrasted with a sample of 120 conventional farms (1.5% of the provincial total) identified under the auspices of the Ontario Dairy Farm Accounting Project (ODFAP). The ODFAP sample was stratified by geographic region in Ontario, then randomly selected within each region. Neither ORG nor ODFAP farm samples contained any hobby or part-time farmers. Scale of operation was comparable on the two types of dairies, with the ratio of ORG to ODFAP being 122% for tillable landbase (ns) and 107% for herd size (ns). Similarly, milk production was comparable from ORG and ODFAP dairies (5,882 and 5,865 liters/cow, respectively; ns). Data on farmer personal characteristics such as age, education level, and management skills were not collected. It was presumed that managerial capabilities were equal between ORG and ODFAP farm samples.

It was hypothesized that total revenue and total cost of production would be greater on ODFAP farms, while net farm income would be higher on ORG than on ODFAP farms. Although the ratio for ORG to ODFAP performance was 93% for total revenue and 77% for total cost of production, neither of these differences was statistically significant. However, ORG dairies yielded 60% more net farm income than ODFAP dairies ($59,718 vs. $37,557; significant at the 5% level). Within the constraints of the supply management marketing system operating in a northern temperate region, ORG approaches to dairy production were shown to be as productive and at least as profitable as those on ODFAP farms, despite reliance on lesser yielding crops and more holistic (less resource-intensive) production methods.

Farmers and the agricultural research and extension community at the land grant universities have experienced an evolving relationship. The current call for reform in publicly sponsored agricultural research and extension is built upon more than a century of dialog. If specialization and discipline-oriented research is to continue, the ecosystem-based knowledge of the farmer will become increasingly valuable. Involving farmers more actively in research and education could be achieved in several ways. Outside the land grant system, nonprofit agricultural research and demonstration organizations are being developed. Within the public system we need a renewed emphasis on extension at the local level and a revitalized applied research effort aimed at solving problems of the agricultural ecosystem rather than single disciplines. A dynamic and resourceful agriculture could result from including the farmer as a full partner in land grant research and education.

Afield study was conducted between 1972 and 1982 to compare the effects of previous crop on row crop yields under rainfed conditions in eastern Nebraska. The objectives were to determine the effects of fallow and three previous crops: corn (Lea. maysLJ, soybeans /Glycine max (L.) Mem], and grain sorghum /Sorghum bicolor (L.) Moench], on the growth and grain yield of the same crops. The study was conducted on a Sharpsburg silty clay loam (fine, montmorillonitic, mesicf Typic Argiudoll). Corn grain yield was most variable (C. V. 23.4percent) compared to soybean (C. V. 13.6percent) or grain sorghum (C. V. 9.5 percent) yields. Corn was also the most sensitive crop to previous crop effects. The range of treatment yields for each crop was 47 percent, 22 percent, and 11 percent of the overall means for corn, soybean, and sorghum, respectively. Previous crop affected yields for all crops, but the effects were not consistent across years. All crops produced highest yield following fallow. Yields of corn, soybean, and grain sorghum following fallow were 74, 25, and 10 percent higher than their respective monoculture yields. In years of average precipitation, a corn-soybean sequence produced the greatest yield. In years having above- or below-normal precipitation, a grain sorghum-soybean sequence produced the highest yield.

Soil erosion is a major threat to sustaining agricultural production in Tanzania. However, quantitative information is scanty on its effects on yields of major crops for principal soils and management practices. We conducted this study to determine erosion effects on soil moisture, related properties and corn yield on Tropeptic Haplustox and Ultic Haplustalf soils at Mlingano in Tanzania. Four erosion classes (least, slight, moderate, and severe) on Tropeptic Haplustox and three erosion classes (slight, moderate, and severe) on Ultic Haplustalf were established according to the thickness of the Ap horizon under natural field conditions. Accelerated soil erosion reduced soil moisture content, soil organic carbon, available water capacity and water use efficiency. Mean volumetric soil moisture content (average of both soils) during the growing season was 23.3% for severe, 24.8% for moderate, and 25.7% for slight erosion. Mean soil organic carbon content was 1.15% for severe, 1.64% for moderate and 1.97% for slight erosion. Mean available water capacity was 2.6 cm for severe, 3.5 cm for moderate, and 4.0 cm for slight erosion. Soil bulk density and excessive degree days of soil temperature above 25°C increased with severity of erosion. These adverse changes accentuated constraints on crop growth and reduced corn (Zea mays) yield on severely eroded soil by 45% and 59% for Tropeptic Haplustox and Ultic Haplustalf soils, respectively. The water use efficiency of corn was 21.6 kg ha-1 cm-1 in the least eroded class versus 17 kg ha-1 cm-1 in the severely eroded class for the Tropeptic Haplustox, and 23 kg ha-1 cm-1 in the slightly eroded and 18.1 kg ha-1 cm-1 in the severely eroded class for Ultic Haplustalf.

Disease resistance, increased crop residues and altered plant and canopy design are the primary strategies being used to solve the major problems of cool season food legumes that are an integral component of cropping systems in the rainfed areas of the U.S. Pacific Northwest. Dry pea, seed pea and lentil predominate among these legumes, but there is increasing interest in chickpea. Several diseases are major hazards to production, including root rots, wilts, powdery mildew, Ascochyta blight, and viruses. Pea and lentil cultivan resistant to root rots, wilts, and powdery mildew are being developed and released. Progress is being made on resistance to v iruses transmitted by aphids, including pea enation mosaic and bean leaf roll. Development of res istant cultivars has been the principal control strategy for several diseases: Ascochyta blight of chickpea and lentil; root rots and wilts of pea, lentil, and chickpea; powdery mildew of pea; and viruses of pea and lentil. Chickpea cultivars resistant to Ascochyta blight were recently made avallable to producers. Another problem is that crop residues are insufficient to control erosion. Research is underway on genetically increasing biomass and residue production in lentil and dry pea and on producing more lignified stems and other plant parts that are more resistant to breakdown during harvesting and subsequent tillage. Increased biomass also might increase grain yields and red uce harvesting losses. The semi-leafless and woody stem traits in pea, the bushy plant types of lentil and chickpea, and diverse pod traits in all the legumes have shown promise for increased yield potential, ease of harvest, and reduced shattering losses.

An annual legume cover crop was evaluated in pecan orchards to increase coccinellids that would reduce pecan aphids. Treatments were a ‘Dixie’ crimson clover and hairy vetch mixture and a grass sod. Coccinellids were abundant on the legume ground covers, but coccinellid density in the tree canopy was rarely affected by ground cover treatment. There were substantial differences between the coccinellid species collected from the legumes and from the trees. In Oklahoma, Olla v-nigrum (Mulsant) and Cycloneda munda (Say) were the main species in the trees, while Hippodamia convergens Guerin, Coccinella septempunctata L, and Coleomegilla maculata lengi Timberlake were dominant species in the legumes. In Georgia, Harmonia axyridis (Pallas) was the dominant species in the trees, and C. septempunctata in the legumes. Pecan aphids at two Oklahoma sites usually were not affected by cover crop treatment, but at the Georgia site, early-season aphids frequently were lower with a legume cover crop than with a grass sod. The accumulated effect of all aphid predators and parasitoids attracted to the legume aphids may have reduced the density of the pecan aphid.

Adoption of agricultural practices that reduce or eliminate chemical use creates tradeoffs among yields and output, production costs and net income at the farm level. If widespread adoption is to occur, potential improvements in human health and the environment from reduced chemical use must be weighed against effects on aggregate farm income and consumer food prices. At present, these tradeoffs are subject to considerable debate.

I review available farm level and aggregate economic studies of reductions in total agricultural chemical use. At the farm level, available studies suggest that organic and low-input farming systems result in declines in per acre yields and in lower net returns than most conventional farming systems, although the studies do indicate that net returns for the two systems can be comparable under some conditions. Several studies suggest that low-input systems perform well with respect to risk criteria. I also discuss the potential influence of government programs on the profitability of some low-input farming systems.

All aggregate economic models conclude that widespread adoption of organic farming would result in decreased yields, decreased aggregate output, increased farm income, and large increases in consumer prices. These models have limitations, however. Recommendations are made for further economic research of the impacts of reducing agricultural chemical use at both the farm and aggregate levels.

The primary objectives of this study were to describe the various pest control and soil fertility management strategies used by North Carolina farmers and to characterize the types of farms and farmers using each strategy. In 1988, a survey was mailed to farmers who had shown interest in alternative methods and a randomly selected control group of conventional farmers. Cluster analysis on crops, inputs, and cultural practices used by crop farmers in the combined sample showed that they fall into three distinct groups. Very few members of the first group apply standard synthetic fertilizers and pesticides. Instead, more than three-quarters of them use cover crops, compost, organic mulch, commercial fertilizers and pesticides labeled as “organic”, resistant varieties, hand weeding, mechanical cultivation, scouting, and biological pest controls. More than half of the second group did not use any nutrient and pest management inputs or practices except synthetic fertilizers, herbicides, and lime. More than three-quarters of the third group reported use of synthetic fertilizers, synthetic herbicides, and lime, but also employed most of the cultural practices reported by alternative farmers. However, they less frequently used labor-intensive practices (such as manuring, mechanical cultivation, and hand weeding) and information-intensive practices (such as scouting and companion planting). Information sources, concerns about farm chemicals, and length of farming experience discriminated better than other socioeconomic factors and farm characteristics between farmers who use conventional chemical inputs and those who use alternative practices. Group 1 farmers differed from Group 3 farmers most sharply in that they rank the cost of pest control products and their extension agents' advice lower, have lower farm incomes, read more information sources promoting reduced synthetic chemicals, own more of the land they operate, and have less farming experience. The only factors significantly discriminating Groups 1 and 2 were that Group 1 fanners rank the importance of their extension agents' recommendations lower and effects of chemical products on birds and wildlife higher, read more reduced-chemical information sources, and have less farming experience.

Reviews of historical and organizational literature provide the backdrop for a general discussion of citizen input into land-grant universities and for a specific case study: the Citizens Advisory/Oversight Council of the Center for Integrated Agricultural Systems (CIAS) at the University of Wisconsin-Madison. This strong citizens' council, established in 1989, took its form in response to institutionally structured fears among university personnel, on one hand, and farmers and citizen groups on the other. Each group's recognition that the other's concerns were legitimate led to an acceptable resolution. We describe the principal characteristics of the resulting successful CIAS Council that is composed of farmers and representatives of the state's environmental community. Such councils facilitate new approaches to integrating the craft and science of farming, and for linking the production side of agricultural systems with policy issues.

Nitrogen, a vitally important plant nutrient, is subject to various losses that affect its efficiency. We tested prilled urea (PU), urea supergranules (USG), green manures (GM) and farmyard manure (FYM) in a rice-wheat cropping system to determine which were the most efficient and economical N sources. The maximum rice growth, yield and N-uptake occurred with USG and with GM (Sesbania rostrata) plus PU. Incorporation of GM saved 60 kg N/ha. On the following wheat crop, GM (S. aculeata) plus PU and FYM plus PU had the highest residual effect on the number of tillers per m2, and straw and grain yield. An increase in N recovery efficiency occurred with combined use of PUand organic Igreen manures compared with PU alone. In areas where USG is costly or unavailable and FYM is scarce, green manures can be a cheap N source that allows small-scale farmers to get sustainable yields in a rice-wheat rotation.

Developing and implementing water management strategies is imperative for achieving food self reliance in Egypt. Key elements of the strategy for increasing total value added from agriculture must be directed at enhancing efficiency of water use for crop production. This should be complemented by measures to ensure the efficient use and improvement of developed and undeveloped land resources. We examine the need to shift from supply management policies to demand management policies to optimize water use by fanners. Key features for sustainable development of agricultural water management include: greater investment; infusion of modern, appropriate technologies; building an adequate physical and institutional infrastructure; development of human resources and expertise; intensified cooperation and linkages; and technology development. Communities should be involved in reversing the trend from supply-driven to demand-oriented policies. This should be compatible with consideration of social dimensions.

Research and extension personnel are beginning to look for new strategies to involve more farmers and the non-farm public in their programs. Two approaches we have used are wholefarm case studies (WFCS) and focus groups. WFCS in Oregon and Washington led to several research and educational programming ideas that are currently being pursued in both states. A focus group to study water quality, nitrate leaching and farming practices in Skagit County, Washington is one outcome of the WFCS process. It is made up of 16 people, including farmers, university personnel, members of environmental groups, and government representatives.

We review these two complementary participatory strategies for systems-oriented sustainable agriculture research and education programs. Both have been very useful for building problem-solving partnerships between the land-grant universities and agricultural and environmental constituents in our area. Noteworthy outcomes include: complementary applied on-farm and experiment station research; farming systems analysis; public education; new linkages with environmental and agricultural interest groups; additional grant funds to address identified priority issues; and interdisciplinary teams that cut across the biological and social sciences and include diverse citizen representation.

Research serves different purposes for scientists and for farmers, and the two groups evaluate research results differently. Scientists are mainly concerned about the chance that they have reached an incorrect conclusion, while farmers are mainly concerned about the chunce they will make an incorrect decision based on the results. Research conducted by farmers on their own farms can be more directly applicable to other farmers' conditions than experiment station research, and therefore can reduce the risk of an incorrect decision.