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.

Within the past decade, low cost and convenient soil tests have been developed and marketed to permit better matching of soil nitrogen levels with crop needs. We explore the factors related to farmers' initial adoption and their commitment to continued use of one such kit, marketed in Iowa as N-Trak. Early adopters of the N-Trak had many of the same personal and farm operation characteristics as farmers who have been early adopters of other farming innovations. Further, the principal factors in differentiating between various levels of commitment to continued use of the kit were perceptions of technological attributes of the kit and, to a much lesser extent, farmer attitudinal factors and personal characteristics. These results suggest that perceived attributes of the technology, especially its returns to time, effort, and financial investment, were critical in the decision to adopt and continue to use the N-Trak kit. Early adopters' decisions to continue using it focused primarily on cost, profitability, and technological issues, to the exclusion of water quality concerns measured by attitudinal items. These findings suggest that providing information that shows the kit's ease, compatibility, and advantages, would be more persuasive than marketing it as a tool to enhance water quality.

While crop rotations improve soil quality indicators and crop yields in humid temperate regions, much less information is available under harsher arid tropical and subtropical conditions. A field experiment conducted from 1990 to 1993 compared the effect of continuous pearl millet and pearl millet-fallow systems with six rotations of pearl millet that included one, two, or three years of a legume (cluster bean or mung bean). Data were collected on several soil quality indicators and pearl millet yield. Continuous pearl millet monoculture for three y ears did not affect soil organic C, NaHCO3-soluble P, DTPA extractable Fe, Cu, Mn, or Zn, or several soil organic N fractions, but slightly increased activity of dehydrogenase and acid and alkaline phosphatase enzymes. Similar trends were observed for fallow-based cropping systems, except that enzyme activities were lower. Cropping systems containing mung bean or cluster bean improved availability of soil N and other nutrients and increased enzyme activity. These effects increased with number of years of legume. Improvements from cluster bean generally were greater than from mung bean. The lowest pearl milkt yield was obtained with continuous pearl millet and no N, and yields f or fallow-based cropping systems were 13% greater than with continuous pearl millet. Grain yields of pearl millet with two or three years of mung bean in the cropping system were, respectively, 37 and 65% greater than for continuous pearl millet; with cluster bean the corresponding increases were 68 and 101%. Pearl millet yield increased with N applications up to 40 kg/ha under all cropping systems, and up to 60 kg/ha for some cluster bean-based systems. Yield of pearl millet following cluster bean was nearly double that of continuous pearl millet. These results indicate that in hot, dry climates cropping systems that include a legume, especially cluster bean, are more productive, use the limited water supply and fertilizer N more effectively, and improve several soil quality indicators more than do cropping systems without legumes.

In March 1997 an international conference was held in Boston, Massachusetts, on the ways that the nutritional value and quality of foods are affected by how they are produced. It was organized by the School of Nutrition Science and Policy, Tufts University, and was attended by people from 19 countries.

The conference theme was interpreted broadly, with “quality” encompassing not only biological and chemical characteristics such as nutrient content, but also social and political consequences of different production systems. In all, 46 papers were presented, the abstracts of which are printed here, followed by the closing address. The 20 papers marked with * are included in the proceedings volume.

The long-term health of a community's food system is an important indicator of its vitality and sustainability. A logical and appropriate way to revitalize a community is by the development of a local food economy. People throughout the United States are designing and implementing sustainable, local food systems that are rooted in particular places, aim to be economically viable for farmers and consumers, use ecologically sound production and distribution practices, and enhance social equity and democracy for all members of the community. This paper reviews the existing literature on local food systems, examines a variety of strategies and initiatives that are currently underway, and identifies steps that community kaders and citizens can use to develop their own local food systems. Finally, I suggest what research is needed to support these community efforts.

Turkey is experiencing pressure to increase crop production per unit area to achieve self-reliance in food supply. The main production concern before 1970 was to increase crop yields to meet the national consumption of an ever-increasing population. During this time the country's capability to produce wheat was insufficient to meet the national demand. After the initiation of the National Wheat Research and Extension Project in 1969 the objectives of wheat production methods were changed to achieve not only higher but more economical yields per unit area. As a result the total area sown to wheat increased by only 9% between 1969 and 1990, whereas yields and total production increased 75 and 90%, respectively. This was due to developing or importing high-yielding varieties adapted to dry areas, increasing use of fertilizers and plant protection chemicals, and timely use of proper tillage made possible with modem equipment. Transferring research results to farmers and exchanging information with international scientists led Turkish scientists to establish the new goal of developing ecologically sound farming systems that could achieve higher, more economical yields per unit area. The key to this approach is to maintain or increase soil organic matter.

Eight dairy farms located in western Ontario were surveyed as part of an ongoing comparative economic study. The sampled farms had been using organic methods for an average of 5.5 y ears and, therefore, were beyond the “transition” stage. Diversified cropping systems were characteristic of these farms, with most crop products (grain and straw) being used directly by the farms' livestock enterprises. Crop rotations were complex, and generally involved sequences of forages and small grains into which cover crops such as oilseed radish and red clover were integrated. Weed control, year-round soil cover, and production of feed and bedding all contributed to the design of cropping systems. Both solid and liquid manures were composted before application. No feed additives or growth hormones were used, but homeopathic remedies, probiotics, and antibiotics were commonly used. The high cost of synthetic fertilizer and concern for the environment were the main reasons given by the f armers f or adopting organic methods.

Although I admire the scientific discipline, I frequently find myself wondering whether the traditional approach to science involving testable hypotheses, replication, statistical significance and repeatability is adequate to meet the challenge of understanding such things as the complexity of whole ecological systems without taking apart and destroying the very object of the study.

The threat to sustainability posed byglobal economic integration and the surging interest in local and regional food systems provide an opportunity to unite the diverse constituencies of the sustainable agriculture movement behind a common political and economic agenda. Neither the campaign to influence the Farm Bill nor a romantic vision of bygone agrarian communities are sufficient to broaden the movement's existing political base and deepen its influence. This paper suggests an alternative approach: grassroots organizing guided by the vision of “community-controlled economic development.” Theory linking this new paradigm in local economic development to sustainable agriculture is presented, along with practical examples from innovative networks promoted by the California Alliance for Sustainable Agriculture (CASA). I analyze the experience of CASA organizations, both separately and as an alliance, to illuminate how a strategic vision of community-controlled economic development can enable the movement to meet three difficult political challenges: holding power accountable; unifying environmental and social agendas; and developing strong leadership accountable to the movement's community base.

Soil erosion is occurring at an alarming rate and threatens soil productivity and crop growth. A regional research committee was formed in the North Central region of the US in 1983 to develop a better understanding of soil erosion and productivity relationships on a broad geographic scale. This paper presents the history, project development and implementation and results of the committee, and a perspective on soil erosion-productivity research approaches. The original project included multistate field experiments on soils selected f or their local extent or agricultural importance. Erosion was classified as slight, moderate, or severe. Cropping practices were continuous corn or small grains, with cultural practices appropriate f or the area. The crop yields on moderately and severely eroded soils were consistently lower than on comparable slightly eroded soils. Precipitation and soil available water holding capacity were the factors most often identified as affecting yields. Other specific limitations were soil- or location-dependent. The most frequent soil limitations were depth of the mollic epipedon/topsoil, organic matter and clay content. Evolving objectives of the committee and state-based research emphases have provided additional information germane to soil erosion-productivity research. More than 40 papers have been published on soil properties, crop growth, management, and modeling as a result of this effort. The regional approach has fostered research on complex interactions among management and environmental factors and led to an increased understanding of functional relationships between soil erosion and productivity.

Management recommendations are needed f or low-input (no N fertilizer) Kentucky bluegrass-dominant/white clover swards, particularly to increase or maintain white clover content. We applied treatments involving different amounts of forage present pre- and postgrazing, with and without harrowing and soil aeration, to a well-established, naturally seeded pasture grazed by dairy cows. Pregrazing dry matter was 2350 or 2700 kg/ha (about 10 or 15 cm tall). Postgrazing dry matter was 1100 or 1575 kg/ha (about 2.5 or 5 cm tall). The sward was composed mainly of Kentucky bluegrass, orchardgrass, quackgrass, timothy, white clover, dandelion, and chicory. Soil aeration and harrowing did not affect botanical composition, plant components, or forage yield. Pre- and postgrazing mass (total forage dry matter per unit area) did not affect botanical composition or plant components, but did influence total forage yield. White clover tended to increase under all pasture-mass treatments. During the second year the lowest postgraz- ing mass produced the most forage (mean: 6685 kg DM/ha). Forage quality of all treatments was excellent (seasonal means: 26% crude protein; 1.6 Meal net energy lactation/kg DM).