Six papers in this issue were presented by Middle Eastern authors at the U.S.-Middle East Conference and Workshop on "Dryland Farming Systems and Technologies for a More Sustainable Agriculture," held at Moscow, Idaho on October 18–23, 1993.

A farming systems trial has been conducted at the Rodale Institute Research Center in Kutztown, Pennsylvania since 1981. Over time, the organic rotation has changed to reflect improved knowledge and experience. The current, three-year rotation (hairy vetch/corn, rye/soybeans, and wheat) focuses on mechanical tillage for weed control and year-round live plant cover for pest control and nutrient supply. We constructed long-term enterprise budgets for the organic and conventional cash grain rotations and compared returns earned during the first years of the study, which for the organic rotation involved investment in soil capital, with returns during two later 5-year periods. The organic rotations during these two later periods produced com and soybean yields comparable with the conventional rotation, but grew higher-value crops less frequently and required more family labor and management. The differences in the profitability of the conventional and organic farming systems depend on whether the analysis includes the initial investment in building up the soil and the value of family labor.

A traditional flooding practice showed promise for reducing pesticide use in Massachusetts cranberry beds. The 4-week long spring flood, termed “late water,” checked pressure of two of the most prevalent and severe management problems, cranberry fruitworm (CFW) and fungal finit rots (CFR). Fruit rot generally was equal or lower and infestation of fruitworm was consistently lower at the late water beds compared with unflooded beds, even though no fungicides were used for CFR control (standard practice is two or three applications per season) and insecticide applications for CFW were cut by almost 70%. Although there were no significant reductions in yield in two of the years studied, a significant decline (about 25%) occurred on late water beds in one year for unknown reasons.

We monitored emergence of morning-glory, pigweed, and prickly sida from seeded populations in no-till plots with no debris (reference plots) or with crimson clover, subterranean clover, rye, or wheat debris. Cover crops were either desiccated by glyphosate or mowed and tilled into the soil. Debris levels, soil temperature, moisture, pH, nitrate, total phenolic acid and compaction were monitored during May to August in both 1992 and 1993. Seedling emergence for all three weed species ranged from <1 to 16% of seeds sown. Surface debris treatments delayed weed seedling emergence compared with the reference plots. Rye and wheat debris consistently suppressed weed emergence; in contrast, the effects of clover debris on weed emergence ranged from suppression to stimulation. Gfyphosate application resulted in a longer delay and greater suppression of seedling emergence in May than in April. In 1993, plots in which living biomass was tilled into the soil were also included and monitored. Weed seedling emergence was stimulated when living biomass was incorporated into the soil. Covariate, correlation and principle component analyses did not identify significant relationships between weed seedling emergence and soil physical and chemical characteristics (e.g., total phenolic acid, nitrate, moisture, temperature). We hypothesize that the observed initial delay of the weed seedling emergence for all three species was likely due to low initial soil moisture. The subsequent rapid recovery of seedling emergence of morning-glory and pigweed but notprickfy sida in the clover compared with the small grain debris plots was likely due to variation in soil allelopathic agents or nitrate-N levels. The stimulation of weed seedling emergence when living biomass was incorporated into the soil was likely caused by an increase in “safe” germination sites coupled with the absence of a zone of inhibition resulting from tillage.

In a 400-day laboratory experiment, soil was amended with rape, sunflower and soybean residues to monitor the quantitative changes in the main inorganic nutrients. Total N, available P, exchangeable K+, Ca2+, and Mg2+ in all the amended samples increased significantly. Generally, the increase in the amounts of these nutrients was maintained until the end of the incubation period, suggesting that the mineralization of the three crop residues enhanced soil fertility. In amended soil samples, disappeared within 14 days, while available N was released as after 60 days in soybean-treated and after 120 days in rape- and sunflower-treated soil, respectively. Water-soluble P was completely lacking in each treatment because of microbial immobilization and adsorption or precipitation processes in soil.

Resources available for dryland farming in Jordan are limited since 91% of the country has an arid climate. Moreover, the available resources are subject to a wide range of natural and human constraints. The farming systems consist of two main types: annual crops such as wheat and barley, and fruit trees such as olives, grapes, and stone fruits. Socioeconomic factors coupled with a fluctuating rainfall pattern cause some shifting in land use and variation in land under cultivation. Alternative land use strategies and preservation and more efficient use of resources are the means to achieve higher production. Substantial addition of land suitable for cultivation is unlikely since it would require additional water resources, which are diminishing in Jordan. Environmental degradation such as desertification is a major concern to land use planners. Several issues must be addressed if agricultural productivity is to be sustained: preservation of resources; overcoming various pressures imposed on agricultural lands; adoption of new practical and economical practices; introduction of modern technologies such as water harvesting, supplemental irrigation, use of treated waste water, and proper soil conservation measures; and adaptive research.

The soil erodibility factor (K) of the Revised Universal Soil Loss Equation is currently considered a constant for all soils in the same type, regardless of production practice. To examine the effect of alternative production systems on the K-factor we compared pairs of alternatively and conventionally farmed fields on a Judson silt loam (Fine-silty, mixed, mesic Cumulic Hapludolls), a Yutan silty clay loam (Fine-silty, mixed, mesic Mollic Hapludalf), and a Wann fine sandy loam (Coarse-loamy, mixed, mesic Fluvaquentic Haplustolls). Soil cores were taken from the surface 10 cm and analyzed for organic matter, permeability, structure, and texture. These data were used to estimate K-factors from a nomograph. All soils in the study had a fine granular structure. Organic matter content and permeability were significantly higher for the alternatively managed field at every location, except for no difference in permeability on the Judson soil. However, the K-factor was significantly lower for the alternative system on the Judson soil. Of all the parameters, texture has the greatest influence in determining K-factors within the nomograph, with soils higher in silt being more erodible than soils higher in sand or clay. Thus, the influences of alternative production systems affected the Judson soil to a greater degree than other textures because of its higher inherent susceptibility to erosion. This study shows that alternative production systems affect the K-factor of some soil types and can reduce soil erodibility, and therefore should be considered when developing conservation plans.

The semiarid regions (SARs) are characterized by extreme temperature changes, low and unevenly distributed precipitation, hazardous torrential rains, and frequent early spring droughts. Barley is the most highly adapted cereal in SARs, but durum wheat is the most widely cultivated. The area in cereals varies considerably from year to year, and yields are low. Tillage practices are used to conserve both soil and moisture and to prepare the seed bed. However, improved fertilizer use and weed control practices are not being used. Without development of needed cultural and tillage practice systems, the genetic potential of today's varieties cannot be realized. Planting depth and rate, row spacing, fertilizer application, and weed control were investigated under conventional tillage and reduced tillage systems. In on-farm trials, reduced tillage did not significantly affect durum wheat yield but slightly increased barley yield compared with traditional practices. Optimum planting depth for both wheat and barley was 7 cm. Higher seeding rates increased the yield of both crops. Highest yields were obtained at planting rates of 140 kg/ha for wheat and 100 kg/ha for barley. At these rates, maximum yields were achieved at row spacings of 30 cm for barley and 20 cm for durum wheat. Use of fertilizer and weed control increased yields substantially. Sustained and increased production in SARs can be achieved with a “package of practices” approach that incorporates these cultural and tillage practices.

We compared conventional and alternative systems for the establishment of apple trees on a replicated, whole-orchard scale. The alternative system consisted of a K-31 fescue sod rotation followed by planting of trees directly into sod that had been kitted with herbicide. The conventional system consisted of a standard corn rotation, accompanied by application of fertilizer and nematicide. Orchard floor management in the three years following tree planting was based on the use of both pre-and post-emergence herbicides in the conventional system and only contact herbicide in the alternative system. The study documented tree growth, pest incidence, and nitrate mobility in the two systems. The alternative system compared favorably with the conventional system for the growth and establishment of four apple cultivars. Many advantages accompanied the killed sod system, including less subsurface leaching ofnitrate-N and lower costs (largely from decreased herbicide use). The alternative system provided an economical alternative to the problem of soil organic matter depletion in conventional orchard soils without requiring increased use of commercial fertilizers. Grower concerns regarding increased potential for vole damage and poor initial tree growth were unsubstantiated.

This paper explores issues of agricultural sustainability in relation to arguments to sustain the family labor farm and the theoretical justification for the recent increase in smallerscale milk processors and differentiated dairy product markets. Using a population of New York State dairy farm households, we identified farm structural variables that influence farmers' use of chemical pesticides and fertilizers and their consideration of intensive rotational grazing. Milk sales, division of hired labor on the farm, and ownership arrangements are found to be interrelated and predict relative use of chemical pesticides and fertilizers within a “conventional” confinement feeding system. Marketing strategies predict production practices within a confinement feeding system less reliably but do predict whether the farm has considered adopting an intensive grazing system. Farms that have higher saks, that use hired labor more extensively, and that are not single family operations are more likely to use chemical pesticides and fertilizers. Farms that sell to differentiated markets are more likely to look favorably on an eventual switch to an intensive rotational grazing system.

Changes in soil physical and chemical properties following conversion from conventional to low-input farming systems could alter root growth in com and hence aboveground growth and yield. The main hypothesis we tested is that low-input and conventional farming systems produce different amounts of corn roots. We compared low-input and conventional farming systems, row position (row and interrow), and soil depth for effects on root length density in a Comly silt loam (Typic Fragiudalf) at the Rodale Institute Research Center in Kutztown, Pennsylvania. On all sampling dates studied (two each in 1989 and 1990) root length density under low-input farming systems was significantly greater than under conventional farming systems. We used analysis of covariance to correct for soil factors that could not be directly controlled. Soil water and bulk density had no clear effect on root length density. In contrast, there was significant covariance of soil organic matter with root length density on two of the four sample dates. Root networks were more dense in soil pockets rich in organic matter for every farming system, row position, and depth. These findings indicate that low-input farmers may be manipulating root production of corn to allow com to absorb more nutrients and water when water in the topsail is limited.

The long-term effects of cropping practices on plant-available micronutrient concentrations in soils of the northern Great Plains of North America have not been adequately determined. We measured micronutrient uptake by wheat in a crop rotation experiment established at Lethbridge, Alberta in 1911. Phosphorus application at low rates (20 kg P ha-1 yr-1) since 1972 suppressed uptake of Zn, Cu, and Ca in the two years in which they were measured, 1991 and 1993. Vesicular-arbuscular mycorrhizal (VAM) fungi are plant symbiotic fungi that are known to increase the uptake of relatively immobile micronutrients such as Cu, P, and Zn. The functioning of these fungi is known to be affected by high-levels of P fertilization. Assessment of wheat roots showed that low-level P fertilization had significantly reduced the length of root colonized and the percentage of roots colonized by VAM fungi. The results show the importance of considering microbial ecology when assessing the effects of agricultural practices, including low-input practices, on soil productivity and crop nutrient value.

The most important source of increased crop yield in the Middle East has probably been the increase in irrigated area although it has been accompanied by other inputs such as chemical fertilizers, improved varieties, mechanization, and pesticides. Palestine, which in this paper encompasses West Bank and Gaza, has had a similar emphasis on irrigation although only 5% of West Bank agricultural land is irrigated. However, the possibility of further expanding or even maintaining present water use for fostering agricultural growth in this dry region is diminishing. There now is a growing understanding that future sustainable agriculture in the Middle East may depend on shifting emphasis to rainfed farming; in the past, this was not considered possible because of its perceived low productive potential. Recent research, however, has evaluated the status of rainfed farming in Palestine and targeted areas that need improvement. Experiments and demonstrations have shown the potential to vastly improve rainfed farming's production, economic return and status. Following up on these initial steps should be an important priority in maintaining food production in this region.

The Illinois Soil Quality Initiative (ISQI) is a multidisciplinary effort to develop accurate, practical, and meaningful measures of soil characteristics that farmers can incorporate in strategies to sustain soil resources over the long term. We discuss how the project integrates soils and social research and involves farmers and others in guiding its research activities. A board of farmers, farm managers and conservation agency personnel and a panel of soil scientists, agronomists, and social scientists established ISQI's goals and monitors its progress. ISQI technical staff gather data at 35 participating farms to assess the accuracy and practicality of several measures of physical, chemical, and biological characteristics of soils under varying tillage and environmental conditions. They communicate findings to farmers and the ISQI board through regional farmer meetings, a project newsletter, and statewide conferences. Participating farmers assess the measures' meaningfulness and practicality, suggest strategies for communicating soil quality information, and recommend new directions for research. These observations have been made at the end of ISQI's first year: definitions of and beliefs about soil quality vary widely, making it inadvisable to think of “soil quality” as a single, inclusive concept; farmers and other land managers want to understand better the relationships among soil qualities, productivity, and sustainability, and to ham how to enhance their soils' structural and biological characteristics; soil quality measures must be accompanied by research and education on how soil qualities are affected by management practices or systems and how they affect yields and the environment; many farmers are only mildly interested in self-administered soil quality measures, preferring instead to purchase such data from commercial sources.

Agriculture in Israel is practiced throughout the country from the Arava Valley in the South, where average annual rainfall is less than 40 mm, to the Upper Galilee in the North, where annual rainfall exceeds 700 mm. Less than half the cultivated area used for field crops is irrigated. Much of the output is exponed, primarily to Europe, but some to the United States and Japan. In nonirrigated dry-farming areas, the main crops grown are wheat for grain and silage and several secondary crops, including sunflower, watermelons and hay legumes. Animal production is predominantly intensive dairying (mainly cows, but also sheep and goats), poultry production, and aquaculture, all of which use large quantities of imported feed grains. Beef production is largely from dairy bullocks, but includes an important rangeland beef sector. Problems that face Israeli agriculture in general and dryland agriculture in particular are primarily economic, including low prices for many traditional dryland crops, a small local market, and increasing input costs. The changing socioeconomic scene, reflected by decreasing employment in agriculture, has added to the problems of proper land use. There is an urgent need for more appropriate production systems and associated innovative research and development. This includes management for higher output/input ratios, conservation and enhancement of genetic resources, crop diversification, integration of crop and livestock production, and alternative land use options such as agroforestry, recreation, ecological refuges, and landscape enhancement. These challenges are common to most countries in the Middle East, and offer opportunities for regional and international collaboration to improve the sustainability of agriculture in the region.