Cuba's agriculture after the 1959 revolution had been based on large-scale, capital intensive monoculture, which made Cuba heavily dependent on the socialist bloc for subsidized agrichemical inputs and for set prices of agricultural exports. However, with the collapse of the Soviet Union and its Eastern European allies in 1989–90, Cuba's inputs of fertilizer, pesticides, and petroleum dropped by more than half Cuba responded with a dramatic shift in its agricultural development model that featured appropriate technology, alternative organization of labor, alternative planning, and environmental preservation. Cuban pest control efforts now focus on biological control and on enhanced monitoring and diagnostic techniques. Soil management emphasizes biofertilizers and vermiculture. Minimum tillage and crop rotation are frequent practices among Cuba's independent farmers, agricultural cooperatives, and state farms. The transition to low-input agriculture has decreased the exodus of people from rural areas to cities, and has lead to establishment of lab or camps with volunteer labor and long-term programs for rebuilding rural communities. To address the loss of important food imports while ensuring environmental conservation, agricultural planning now gives priority to crop rotations, city gardens, and introduction of food crops in sugar cane areas.

Over the past half century, American agricultural productivity has increased while the number of full time farmers and rural populations have decreased. Although most people believe we have a safe, nutritious, and affordable food supply, the high level of productivity has had negative impacts on the environment and rural communities and has increased farmers' dependence on purchased inputs. As Americans become more concerned about food safety and the environment, a new paradigm for American agriculture is emerging. This new alternative agriculture takes an ecological approach to food production. The challenge facing the land-grant university system is how to answer questions about sustainable agricultural systems, maintain productivity and respond to the needs and concerns of their broadened clientele. Whole farm case studies, focus groups, farm improvement clubs, on-farm research, field-size research trials, and whole farm comparisons are new qualitative and quantitative methods for interdisciplinary research and education. These methods integrate biological and social strategies and bring community members into the research and education process. When these groups work together, questions critical to maintaining the long-term sustainability and productivity of agricultural systems can be answered.

As historical background helpful to understanding current concepts and practices of apple pest management, we review the origin and rise of key pests of apple in North America and the evolution of approaches to their management, culminating with the concept of integrated pest management (IPM). We propose four levels of integration of orchard pest management practices. First-level IPM integrates chemically based and biologically based management tactics for a single class of pests, such as arthropods, diseases, weeds or vertebrates. Second-level IPM, the focus of our effort here, integrates multiple management tactics across all classes of pests. We describe components of second-level IPM for Massachusetts apple orchards, which are threatened each year by an exceptionally broad range of injurious pests. We illustrate the tentative advantages and shortcomings of second-level IPM using 1993 data from six commercial orchard test blocks. Our predominant approach was to use chemically based tactics for controlling arthropods, diseases and weeds early in the growing season, and afterwards to rely exclusively (for insects) or largely (for other pests) on biologically based tactics, such as cultural, behavioral, and biological controls. Compared with nearby first-level IPM blocks, insecticide use in 1993 was reduced substantially (about 30%), with only slightly more insect injury to fruit and little difference in populations of foliar insect pests. The results for mite pests and diseases were less encouraging although summer pruning significantly reduced disease injury caused by flyspeck. We discuss how second-level IPM poses special biological or operational challenges to apple pest management practitioners. The concept has merit, but refinements are necessary before it can be recommended broadly to commercial apple growers in Massachusetts as an economical and reliable alternative to first-level IPM.

What scientists include among the essential attributes of sustainable agricultural systems can influence the development of agricultural research agendas and how research is done. Current perspectives on sustainability place varying emphasis on environmental and agrarian values and propose different amounts and kinds of change in agricultural production, agricultural science, and rural social institutions. In a delphi study, agricultural scientists at North Central region land-grant universities considered environmental management and development of new farming technologies as essential to a definition of sustainable agriculture, but gave little importance to social or scientific restructuring. With some qualifications, we characterize their view of sustainability as a stewardship perspective that does not include social considerations and explicitly rejects radical social change.

One widely held view of the future of American agriculture is that it will continue the current trend toward fewer but larger farms, greater centralization and vertical integration, and declining rural populations. If so, the research, teaching and extension institutions created to serve agriculture will not survive unless they can adapt to changing political and demographic conditions, especially the domination of the suburbs. This will require these institutions to set new goals for themselves. Their historic pursuit of increased technical efficiency already has been so successful that it has sharply reduced the farm population, which has been their main base of public support. Suburban America, in contrast, will demand an agriculture that is more in harmony with nature. Alternative notions of the Common Good can provide the philosophical basis for this shift Historically, the economic system, including agriculture, has regarded nature as something to be used to advance human well-being. In this view (which could be called “Liberal” in the 19th century sense of the term), the reason to protect nature is to insure that it can continue to serve human needs. In contrast, the “Ecocentric” view of the Common Good emphasizes that humans are part of an ecological community, and that we must optimize the balance between human needs and the health of the ecosystem.

Amaranth is an alternative grain crop that shows significant promise in the U.S. A geographic information system (GIS) was used to analyze the most suitable regions for growing amaranth in Missouri. GIS software provides tools to manipulate and display geographically based information, in this case the factors affecting amaranth's suitability. Of several such factors considered, the ones used were soils, rainfall, sorghum production, disease potential, and labor availability. Soil, rainfall, and disease information were assumed to be direct factors in yield potential. Current sorghum production areas were considered likely areas for amaranth production, given the similarities between the crops. Labor availability also was assumed to affect adoption, since amaranth requires more labor than traditional grain crops. The analysis showed that central and southeastern Missouri would be the most favorable areas for amaranth production. Other suitable areas are along the Mississippi and Missouri river valleys and in western Missouri. This GIS approach can be modified to include additional factors and refinements, and could be used with other alternative crops or for other regions of the country.

Vesicular-arbuscular mycorrhizal (VAM) fungi colonize plant roots and the surrounding bulk soil. They transport mineral nutrients from the soil to the plant and carbon compounds from the plant to the soil, and have pervasive effects on plant form and function and on the composition of the soil microbiota. This experiment evaluated VAM effects on plants and soil to determine if VAM fungi mediate a relationship between changes in seed yield and soil aggregation. In a pot experiment with peas, an isolate of the VAM fungus Glomus mosseae (Nicol & Gerd.) Gerd. and Trappe did not significantly affect seed yield (8%), but improved soil aggregation by 400% in one soil, a gray silt-loam high in organic matter (OM) and phosphorus. In another soil, a yellow clay-loam low in OM and phosphorus, seed yield was enhanced significantly (57%), but there was only a small change (50%) in aggregation. The results suggest that carbon allocation between the plant (measured as seed yield) and the soil (measured as the formation of water-stable aggregates) is influenced by this VAM fungus. The soil appeared to gain carbon at the expense of carbon lost by the plant Mycorrhizal fungi thus seem to affect two biologically controlled aspects of sustainable agriculture: plant production and soil quality.

Unlike other creatures, humans have the unique ability to delay their own extinction. We can store, analyze and transmit information to the next generations, and education helps us adapt to varied ecological situations. Looking beyond the 21st century to a post-industrial society where biological systems will emerge as the most renewable and sustainable activities on the planet, we need educational systems to prepare creative problem solvers who can confront and adapt to change and be willing to move toward lifelong growth and learning. Students need to understand the complexity of biological systems and the importance of connectedness. We need to educate them about watersheds and ecosystems, about the roles of a wide range of species and how they interact, and about long-term sustainability. Some programs already involve interactive student activities, case studies, and real world examples, and have empowered students to formulate their own approaches to challenges. A new initiative in the North Central region includes a structured experiential program in practical agroecosystem studies that taps into the technical and financial resources in the region's 12 land-grant universities and other organizations. In the future, we will need to forge more linkages between education and research, understand the impacts of alternative strategies for food production and other human needs, and search for ways to empower people to pursue their own educational agendas. This approach should include a mosaic of educational opportunities that will promote the survival of our species beyond the 22nd century.

In a previous study of reduced chemical cropping systems (N from legumes; chisel plow and disk tillage; cultivation for weed control) in the southeastern U.S., corn and wheat yields were less than half those obtained with recommended practices. The following practices were studied as possible ways to improve yields in the reduced chemical systems: 1) conventional tillage (chisel plowing and disking), inorganic Nat 70 or 140 kg/ha, and either cultivation or herbicides; 2) early versus late plow-down of clover green manures; 3) supplemental inorganic N fertilizer on corn and wheat in rotations relying on clover green manures for N; and 4) nicosulfuron herbicide banded on corn.

Yield of soybean in the rotations was not affected by any of these practices. With herbicides and fertilizer N at 140 kg/ha, continuous corn yields with no-till and conventional tillage were equal in 1990 and 1992, but no-till yield was 30% higher in 1991. When cultivation was used for weed control in the conventional tillage treatment, corn yield was similar to that of no-till with herbicide in the one year when rain was plentiful (yield 6000 kg/ha). However, in 2 of 4 dry years, yields (<2600 kg/ha) were higher with no-till. Clover biomass consistently increased by between 700 and 3500 kg/ha when plow-down was delayed from mid-April to early or mid-May (13 to 26 days). However, biomass N content increased significantly (by between 35 and 90 kg/ha) in only 2 of 5 years. Corn yields were affected in only 2 of 12 possible comparisons. In these cases, delayed clover plow-down reduced yield by about 50%. Supplementing corn with 45 kg N/ha and banding nicosulfuron increased yields, but only to between 62 and 84% of yields with recommended practices. Supplementing wheat with 45 kg N/ha increased yields by half, but only to between 40 and 60% of the yields with 90 kg N/ha.

Sustainable agricultural research and education have gained acceptability within the land-grant system, but they still must be fully integrated into its fabric. Challenges remain in three key areas: knowledge generation, research and education, and funding. New biological and ecological knowledge is needed on plant-animal-human-environment interactions from the microbial level on upward so that we can move beyond anecdotal evidence of biological integration efficiencies to scientific understanding of the underlying processes and opportunities for human intervention. Socioeconomic research must address human motivations to change farming methods and the likely impacts of these changes on farmers, consumers, other species, and the quality of the environment.

Generating this knowledge will affect the integration of research and education. Having farmers set the research and outreach agenda dissolves the old distinction between research and extension. This situation is complicated by budgetary stress and uncertainty about the dividing line between public and private responsibilities. The funding of sustainableagriculture creates a dilemma. Earmarked funding has helped legitimize sustainable agriculture in the land-grant university, but if it fails to become integrated into the routine land-grant research and education agenda, it will lose its newly gained momentum in the event those funds disappear.

Research on agricultural production has been largely the domain of an institutional system established especially for the purpose. However, the complexities and diverse character of agriculture require diversified modes of research. Such a strategy might be better pursued by a more diversified set of research institutions. Non-land-grant institutions, although lacking the land-grant system's strong experience in agriculture and its close ties with farmers, potentially represent a large pool of scientific expertise in a broad range of fields relevant to agriculture. Also, they are under different institutional constraints, and may be in a better position to do more speculative, long-range research that does not promise immediate practical benefits. Although such research has been criticized by people in the sustainable agriculture movement who believe that research should be more directed at farmers' current problems, a truly sustainable agriculture will require a deeper grasp of how agricultural systems work. Achieving this will demand a breadth of understanding that extends beyond the production-oriented studies that dominate current sustainable agriculture research programs.

We evaluated selected cool-season annual and perennial legumes as potential ground covers to supply nitrogen and to increase beneficial arthropod populations in a pecan orchard. Densities of aphids (Homoptera: Aphididae), lady beetles (Coleoptera: Coccinellidae), damsel bug (Hemiptera: Nabidae), green lacewings (Neuroptera: Chrysopidae), brown lacewings (Neuroptera: Hemerobiidae), hover flies (Diptera: Syrphidae), spined soldier bug and other stink bugs (Hemiptera: Pentatomidae), and spiders (Araneida) were monitored at 7–14 day intervals during the growing season for three years. Aboveground biomass production and nitrogen content of the legumes was measured for two years. Aphids peaked during early spring each year, with the highest density usually on ‘Dixie’ crimson clover and ‘Kenland’ red clover. Density of lady beetles was positively correlated with that of aphids, but spider densities were not. Other arthropods usually were not abundant. Nitrogen in the tops of the annual legumes ranged from 20 kg/ha to 89 kg/ha when assessed after a single harvest at anthesis; for the perennial legumes it was from 108 kg/ha to 179 kg/ha following two harvests in June and September. We chose two annual legumes (‘Dixie’ crimson clover and hairy vetch) and two perennial legumes (‘Louisiana S-1’ white clover and ‘Kenland’ red clover) for further evaluation.

Conventional Midwestern U.S. row crop agriculture has created significant environmental problems and made the farm economy reliant on government subsidies. Environmentally friendly and economically profitable alternatives are badly needed. This study addresses production characteristics of strip intercropping, a system that may meet both requirements. Two experiments were conducted in 1989 and 1990: one on a cooperating farmer's field with ridge tillage and the second at a university research farm with conventional tillage. The objective was to evaluate grain yields of different rows in adjoining strips (3.8 or 4.6 m wide) of three crops. Corn, soybean, and oat strips were either inter seeded with nondormant alfalfa or seeded with hairy vetch as a cover crop after oat grain harvest. Outside corn rows had significantly higher yields than center rows in 1990, when plant water stress was low, but under dry conditions in 1989, early season competition for water caused corn to yield less in the row bordering oat than in the row bordering soybean. Comparative soybean yields in border and center rows also depended on rainfall; with adequate water, soybean yield next to the oat strip was greater than or equal to yield in the center of the strip. Oat border rows yielded higher than those in the oat strip center. Timing differences in crop life cycles and water availability seem to influence how these crop species interact, particularly at the border positions. Overall, the strip intercropping system seems a suitable alternative to current practices.

Practical Farmers of Iowa was founded in 1985 to help farmers generate and share information on environmentally sound farming methods. Its on-farm research trials allow farmers to do statistically valid comparisons of competing techniques, such as different weed control methods. However, sustainable agriculture means more than providing farmers with adequate information about appropriate techniques. It also requires policies that reward farmers for adopting sustainable methods and that support rural community well-being.