Weeds are considered the most important pest group for farmers interested in lowering external inputs and avoiding synthetic chemical use. Corn gluten meal (CGM) is a natural preemergence weed control used in turfgrass, which reduces germination of many broadleaf and grass weeds. The objective of this study was to investigate weed cover and vegetable seedling survival in field plots when CGM is incorporated before planting. Three studies were conducted, with three replications for each study. Five rates of powdered CGM (0,100, 200, 300, and 400 g m–2) were weighed and incorporated into the top 5–8 cm of soil in recently disked 1.5-m by 2.7-m plots. Seeds of eight vegetables were each planted in rows 1.4 m long and 0.3 m apart. Seedling survival and percentage of weed cover were recorded for each plot. Corn gluten meal at rates of 100, 200, 300, and 400 g m–2 reduced mean weed cover by 50, 74, 84, and 82%, respectively, compared with the control. Seedling survival at 100 g CGM per m2 was reduced by 67% for ‘Comanche’ onion, 35% for ‘Ruby Queen’ beet, 41% for ‘Red Baron’ radish, 71% for ‘Provider’ bean, 73% for ‘Scarlet Nantes’ carrot, 59% for ‘Maestro’ pea, and 68% for ‘Black Seeded Simpson’ lettuce, compared with the control. Seedling survival for ‘Daybreak’ sweet corn was not reduced by rates of 100 or 200 g CGM per m2, but was reduced by 26% at a rate of 300 g CGM per m2 compared with the control. Because of the reduction in seedling survival at even the lowest rate of CGM (100 g m–2), direct seeding of these vegetables into soil into which CGM has been incorporated is not advisable. Using transplants may be an alternative that takes advantage of the herbicidal effects of CGM and the nitrogen it provides.

Alley cropping is a form of hedgerow intercropping where fast-growing leguminous trees are planted at dense within-row spacing, with agricultural crops planted between the hedgerows. This agroforestry technology, with the hedgerows planted on the contour across the slope, appears promising for small farmers on the hittslopes of Haiti An agroforestry outreach project operating in Haiti since 1981 has helped thousands of farmers plant hedgerows on their farms. The farmers are increasingly accepting the technology: the length of hedgerows planted by the farmers in the project area increased from 11 lineal km in 1987 to 140 lineal km in 1988. An evaluation of 50 farms where hedgerows had been installed shows that this technology results in soil conservation and microsite enrichment between hedgerows; the hedgerows also provide fodder and fuelwood. However, refinements are needed in technical aspects of hedgerow management, such as planting configurations, pruning regime, and choice of species. Moreover, soil and plant parameters as well as socioeconomic characteristics must be monitored in a systematic way in order to assess the impact of hedgerow intercropping on the sustainability of Haitian farming systems.

Agroecology is the development and application of ecological theory to the management of agricultural systems, according to the specific land and other resources available. Beyond the biological and climatic dimensions of agriculture and ecology, there is growing appreciation of the influence of social, economic, and political factors on the structure and success of farming systems. This broader field is becoming known as “agroecology and sustainable development.” Expansion of the conventional curriculum to include integrative themes is essential because of the need for students to appreciate a whole farm focus for analysis, to understand the impact of socio-economic factors, and to further develop their abilities to link people and environment. Two courses are proposed and described in detail “Biology of Agroecosystems” includes study of system structure and function, cycles and interactions among components, system development and performance, and the importance of resource conservation and use. “Agroecology and Sustainable Agricultural Development” includes a survey of systems around the world, an evaluation of resources and their use, the environmental impact of agriculture, the relationships between society and agriculture, the applications of agroecology to rural development, and some projections of alternative future strategies for food production. Future agricultural professionals need to understand how improvement of agroecosystems is closely linked to economic, cultural, and political systems, and how they are both enhanced and constrained by factors beyond biology and climate.

A mailed survey was sent to 174 Midwestern organic farmers originally studied in 1977. We obtained information on 133 of this group, 96 of whom are still farming at the same location, although 12 no longer use organic methods. Fifty-eight currently active farmers returned a detailed questionnaire that covered their perceptions of the advantages and disadvantages of organic farming, some of their practices, and their financial status. Most farmers who employed organic farming methods stated they did so out of concern for the health of themselves, their families, and their livestock. Compared to ten years ago, philosophical or religious considerations were less frequently mentioned as an advantage of organic farming. In contrast, some agronomic and management disadvantages of organic f arming were mentioned more often. The farmers now are more tolerant, in principle, of some chemicals not generally accepted in organic farming, but regular use of soluble fertilizers and synthetic pesticides has not increased appreciably. The farmers reported little change in the institutional and social environment for organic agriculture, including available markets, information sources, and the attitudes of their neighbors.

The combination of several measures (organic matter accumulated, soil porosity, field soil respiration, CO2 evolved during incubation, and mineral N released) shows clearly that soil biological activity was enhanced in the systems that minimized tillage. Surprisingly, the abundance of earthworms, which are considered very sensitive to damage by tillage, did not always follow the same pattern. We do not know the reason for the response of earthworms, but in part it may have been an artifact of the interaction of the collection technique with soil properties such as infiltration rate and temperature. The most dramatic improvement in porosity, organic matter accumulation and N mineralization ability came from five years' continuous growth of grass sod, underscoring the potential role of grass in sustainable cropping systems and the value of grass for soil conservation and improvement.

The positive role of biological diversity in enhancing agricultural sustainability is presented in the context of crop rotation. Once common in virtually all farming systems, crop rotations have been simplified or eliminated during the past two decades from farming systems in most industrialized countries. Specialization, production intensification, government commodity programs, and the resulting short-term economic decisions have all had an influence in reducing crop rotation and diversity. Economic and environmental concerns have raised the question of agricultural sustainability in the public arena. We discuss here the role of diversity and crop rotation in relation to the sustainability issue, including matters of agronomic, economic, and environmental benefits, as well as increased efficiency in the use of fossil fuels. Constraints and future directions in the use of crop rotation in modern agriculture are described.

Systems that reduce the use of fertilizers and pesticides are commonly said to do so by greater use of information and ecological understanding. However, this plausible proposition has not received much empirical examination. Different possible roles of information have not been clearly differentiated: in the development of new methods, in the farmer's decision whether to adopt them, and in their continued use. Also, the additional work that might be needed to handle information in reducedchemical systems often is not distinguished from the need for greater management ability. Typical procedures for evaluating the performance of alternative systems do not give enough attention to farmers' management ability and use of information. This is also true for research on conventional systems, even though in such systems information and management are not usually considered to have such a critical role.

The development of production systems that provide the benefits of reduced tillage and also reduce or eliminate herbicide inputs presents a challenge to practitioners of sustainable agriculture. This research was conducted to evaluate management approaches for minimum-tillage corn production in a hairy vetch cover crop, specifically, mechanical versus herbicidal methods for pre-plant cover-crop kill and for post-emergence control of emerged weeds. Pre-plant treatments included 2,4-D [(2,4-dichlorophenoxy)acetic acid] plus residual herbicides, 2,4-D alone, flail mower, corn stalk chopper, light disk and heavy disk. The pre-plant herbicide treatments were followed by a post-emergence treatment of dicamba, whereas the pre-plant mechanical treatments were followed by post-emergence cultivation, as needed, for weed control. The mechanical treatments that kept residue on the soil surface (mower, stalk chopper and light disk) killed hairy vetch when it was flowering, but not when vegetative. The herbicide treatment with pre-plant 2,4-D alone, followed by dicamba post-emergence, controlled annual broadleaf weeds (the dominant species in these experiments) similarly to treatment with 2,4-D plus residual herbicides, suggesting that residual herbicides may be eliminated in cover-crop-based no-tillage systems. The pre-plant mechanical treatments followed by cultivation did not control annual broadleaf weeds as well as herbicide treatments, but did maintain final populations below threshold levels in two of four experiments. The stalk chopper and light disk left high levels of vetch residue on the soil surface, and reduced initial broadleaf weed populations compared with the heavy disk that incorporated residue. However, broadleaf weed populations were reduced with less efficiency by cultivation of unfilled soil following the stalk chopper or light disk (38–69%) than by cultivation of tilled soil following the heavy disk (87–95%). Thus, although maintaining surface cover-crop residue without tillage initially reduced weed emergence, it also reduced the efficiency of cultivation, leading to similar final weed populations in all mechanical-based, pre-plant treatments.

We tested the usefulness of mulching with polypropylene landscape fabric and compost as alternatives to bare soil for growing red cabbage and watermelon. Polypropylene landscape fabric has features similar to the polyethylene film that is popular for commercial vegetable production, but its durability permits multi-year use, which would reduce excessive waste produced from the typical single-season use of polyethylene film. On the other hand, compost used as mulch enhances soil development while providing weed suppression and water retention, among other benefits. Yields of red cabbage and watermelon were measured for 3 years in plots receiving either 10 cm compost, landscape fabric, or no mulch. Labor associated with crop production and weed suppression was measured as time spent on each task. Cabbage yields over 3 years followed the treatment order of compost > no mulch > fabric, while for melon yields it was compost > fabric > no mulch. Total labor required over 3 years for both crops, according to treatments, was fabric > compost > no mulch. However, labor for the fabric-treated plots dropped sharply after the first year, because fabric was left in place after initial placement. Labor for unmulched cabbage plots increased over time due to weeding and transplanting; labor for unmulched and compost-mulched melon plots increased for the same reasons. Compost provided the highest crop yields with a moderate labor investment. Surface-applied compost substantially increased underlying soil nutrient levels. The study indicates that polypropylene landscape fabric may be a potential alternative to the more traditional polyethylene film for permanent beds in vegetable production.

Quantitative data are needed to understand how alternative farming practices affect surface infiltration of water and associated surface soil properties. We used a rainfall simulator, double ring infiltrometer, small single ring infiltrometers, and tension infiltrometers to measure water infiltration for Clarion loam (fine-loamy, mixed, mesic Typic Hapludoll) and for Webster silty clay loam (fine-loamy, mixed, mesic Typic Haplaquoll) soils located on a conventionally-managed and an alternatively-managed farm in central Iowa. Steady-state measurements suggested that infiltration rates were somewhat higher for the alternative farming system. Bulk densities were sometimes lower, and volume of large pores was a little higher for the alternative farming system. Small single rings were more reproducible than rainfall simulators or double ring infiltrometers, and data trends were the same as for rainfall simulators.

Farmers' markets promote alternative agriculture by allowing farmers to meet the demand for specialized agricultural products and establish new businesses. Farmers sell at farmers' markets for social and personal, as well as economic, reasons. Successful farmers' marketing involves interactions with customers, but little is known about these interactions. This study aimed to determine what happens when a family shops at farmers' markets, specifically how parents and children interact in the market in relation to each other and to the farmers. Systematic observation was used to follow 22 families with young children. A coding sheet was used to categorize sensory, perfunctory, informational interactions, attempts to influence purchases and additional interactions. Results showed information was more likely to be exchanged between farmers and parents or parents and children. Children were more likely to be involved in sensory interactions. Farmers interact with families through perfunctory interactions or informational interactions, rather than encouraging them to buy specific items. Since some important societal benefits of farmers' markets can only be achieved if information is exchanged during interactions, market managers and outreach professionals should encourage and assist farmers with providing information to customers. Further research is needed to understand why farmers favor social over explicitly sales-focused interactions, which interactive strategies may be optimal to achieve the fullest economic and non-economic benefits for both farmers and customers, and what is the economic and non-economic impact of providing information in the farmers' market.

Educators in ecological agriculture are developing learning environments that differ in three fundamental ways from conventional teaching in agricultural universities and colleges. First, increased emphasis on food and production systems will expand and complement the current focus on specific disciplines and technologies. Second, introduction of research methods and learning objectives from social sciences will broaden the potentials for students to understand the complexities of food systems and the people who make them work. Third, action research and education will move learning activities into the agroecosystems environment and the human landscape, where students will learn from a broad array of people and experiences. This design of a new learning environment will enhance the education of students to serve agricultural and food systems well into a future that is changing at an accelerating rate.

A 2-year study compared milk production and profitability for confinement feeding versus rotational grazing. Guernsey and Guernsey x Holstein cows grazed perennial grass pastures from mid-May to October or were fed in confinement. Averaged over both years, confined cows produced 7% more milk; their milk was similar in fat concentration to that of grazing cows. Body weight changes and health of the two groups were similar. Net return per cow averaged $64 higher for rotational grazing than for confinement because of lower costs for feeding, facilities, equipment, and labor. Intensive rotational grazing of pastures is a competitive alternative for dairy cow feeding. However, farmers in the northern U.S. will still require stored feeds from late fall through early spring.

Winter legume cover crops are receiving increasing attention from agronomists and farmers as a source of nitrogen for summer crops. While agronomists are continually providing new technical information on using legumes as a nitrogen source, little is known on the economics of their use. Previous economic research on legume cover crops has focused mainly on budgeting analysis. In the present work, a twofactorial experiment was designed to test the use of legumes as a nitrogen source for corn (Zea mays L.) in north Georgia. The first factor was winter cover crop with treatments being crimson clover (Trifolium incarnatum L.), hairy vetch (Vicia villosa Roth), wheat (Triticum aestivum L.), and no cover crop or winter fallow. The second factor was nitrogen (N) fertilizer applied at five different rates: 0, 25, 50, 100, or 200 pounds per acre. For each combination of the two factors, mean yield and yield variance were determined. Results indicated that legume cover crops increased both average corn yield and yield variance. The greater yield variance from the use of legume cover crops increases economic risk. Risk-averse farmers must be compensated for increased profit variance by higher average profits. A safety first method was used to evaluate the tradeoff between average profit and profit variance for the risk-averse individual The results showed that hairy vetch with 50 pounds of N per acre was the best combination of cover crop and fertilizer rate for risk-neutral farmers. For risk-averse farmers, hairy vetch without any nitrogen fertilizer is preferred.

Conventional agriculture is increasingly criticized as being too concentrated in ownership; too reliant on technology, petroleum-based inputs, and credit; too specialized and ecologically unsound; and too dependent on government subsidies. Alternative agriculture is offered by many as an alternative, and we discuss the possible impacts of its widespread adoption on farm income, yields, regions, labor, trade, environmental quality, and farm structure. The profitability of alternative agriculture is also examined - in so doing, a distinction is made between the adoption of low-input practices and a more holistic alternative agricultural system.

Strip intercropping seeks to capture the biological efficiency of intercropping in traditional agricultural systems and is compatible with agricultural equipment used in the U.S. This efficiency stems from complementary use of resources by constituent crops and is a function of crop selection, strip width and orientation, weed control, and other factors. Strip intercropping requires a high level of management; further, some reports suggest the gains and losses more-or-less balance in actual production situations. These questions are best addressed by the performance of strip intercropping as implemented by farmers in production situations.

Practical Farmers of Iowa (PFI) members have worked with Iowa State University agronomists to evaluate strip intercropping. For three years six farmers compared strip intercropping to field blocks of individual crops. The strip intercrop systems employed three crops: corn, soybeans, and small grains with a forage legume underseeding. The comparison systems, crops grown in sole-crop blocks, consisted of the same three crops on four farms (planting pattern comparison) or, on two farms, just corn and soybeans in rotation (systems comparison). Yields and field operations were recorded and entered in the Iowa State University Crop Enterprise Record System (CER) to derive gross profit, total production cost, and net profit for each crop component and for each cropping system on every farm. Strip intercropping net profit was generally greater than that in field blocks, and intercropping compared favorably with CER results obtained from corn-soybean rotations on other farms around Iowa. Land equivalent ratios (LER) were usually greater than 1.0, indicating satisfactory biological efficiency. Despite occasional problems, in this set of 18 site-years strip intercropping was associated with greater stability of net profit.

The problem of land degradation is not new, but never before has it been so widespread or affected the lives of so many people. The need for a global assessment of land degradation was highlighted by the United Nations Conference on the Human Environment in 1972. Since then, several attempts have been made to develop methodologies that will allow for systematic assessment and monitoring of global land degradation. Systematic work started in 1975, when FAO and United Nations Environment Programme (UNEP) collaborated in a study to develop a provisional method for soil degradation. This method was tested, and maps on a scale of 1:5,000,000 were produced for North Africa and the Near East. However, the method proved difficult to apply accurately, so this project was followed by another where the method was revised and refined in an effort to assess and map desertification. Again, problems were encountered because of the complexity of the subject and the lack of usable reliable data. More recently, ISRIC, using a simplified methodology and the assistance of some 250 scientists from around the world, has produced a world map of human induced soil degradation at a scale of approximately 1:10,000,000. Meanwhile, interest has been growing in the problem of nutrient depletion in developing countries and a study has been completed of N, P and K balances in the soils of 38 African countries. Although we still do not have an accurate assessment of global land degradation and no systematic monitoring is yet in place, these innovative studies have provided us with a sound basis for future work and have identified many of the practical problems of measuring land degradation, data collection and analysis that will have to be overcome before more accurate assessment and monitoring can be achieved.

Intercropping is an agricultural system widely practiced in the tropics and becoming more widespread in temperate regions. The vast majority of varieties currently grown in intercrop have been developed in and for monoculture, although some breeding programs specifically focused on intercrop systems have been initiated. It is not clear if selection in monoculture is adequate to identify varieties adapted to intercrop, nor is it clear if varieties selected for intercrop performance with one companion will be adapted to another crop combination. The aims of this study were to determine the extent to which selection of corn in monoculture would identify types adapted to growth in corn—bean or corn—clover intercrop, and to determine how selection in one of the intercrops (corn—bean or corn—clover) would compare with selection in the other. The corn used consisted of two groups that had been selected in monoculture, and two that had been selected in corn—bean intercrop. All groups were evaluated in monoculture, corn-bean intercrop, and corn—clover intercrop. Analysis of variance showed that the ranking of the four selection groups was not significantly different when the two intercrops were compared, but was significantly different (P < 0.05 for comparison of clover intercrop and monoculture, and P = 0.07 for comparison of bean intercrop and monoculture) when either of the two intercrops was compared with monoculture. Correlation analysis of corn traits and corn yield in the three cropping systems revealed more similarities between the intercrops than between either intercrop and monoculture. Plant height and leaf area index were more strongly negatively correlated with days to flower in both intercrops than in monoculture. Correlation analysis also revealed some differences between the intercrops, particularly with bean and clover yields. Clover yields were not adversely affected by early growth and maturity of corn, but bean yields were. We conclude that selection of corn in monoculture is not ideal when lines adapted to cornclover intercrop or corn—bean intercrop are desired. Furthermore, selection in either intercrop will identify corn types adapted to the other, as early vigor and maturity allow best corn performance in both crop combinations. Thus, individualized breeding programs may not be required to adapt a crop to growth in association with relatively different companions.

Despite efforts to develop intensive poultry production, family poultry (FP) is still very important in low-income, food-deficit countries (LIFDCs). In LIFDCs, the keeping of poultry by local communities has been practiced for many generations. FP is an appropriate system for supplying the fast-growing human population with high-quality protein. It can also provide additional income to the generally resource-poor small farmers, especially women. Although requiring low levels of inputs, FP contributes significantly to food security, poverty alleviation and ecologically sound management of natural resources. FP is also a source of employment for underprivileged groups and less-favored areas in LIFDCs. Developing schemes that aim to promote and improve the FP sub-sector in a way that is sustainable must not underestimate the roles and contributions of women. However, getting new information to the front line of production requires more gender-disaggregated data. This paper stresses the need to design, implement, monitor and evaluate FP development programs by taking into account socio-cultural, especially gender, issues.