We evaluated the effect of compost enriched with rock phosphate on the yield and phosphate nutrition of rye grass in a calcareous clay loam soil. Enriched compost was prepared by composting either Mussoorie rock phosphate (MP) or Hyper rock phosphate (HP) separately with wheat straw for up to 120 days. A significant amount of insoluble P was solubilized from both kinds of rock phosphates and converted to water soluble, organic, and formic acid soluble P fractions during composting. MP-enriched compost (MPEC) and HP-enriched compost (HPEC) contain 0.30% and 0.34% water soluble P205, 1.94% and 1.42% organic P2O5 2.82% and 3.28% formic acid soluble P2O5, and 1.76% and 1.18% insoluble P2O5, respectively. In a greenhouse study, the yield of ryegrass (three cuttings) with both enriched composts was not significantly different from that of single superphosphate fertilizer (SSP). Phosphorus fractions of soil before sowing and after harvesting the rye grass showed that fixation of P with native soil calcium was much higher with SSP than with enriched composts. No significant differences were observed between MRP and HRP.

We conducted a field study at the Rodale Institute Experimental Farm, Kutztown, Pennsylvania, in a high-P soil to examine the interaction of farming system and tillage on the potential functioning of arbuscular mycorrhizal (AM) fungi. Plots under conventional and low-input systems were either chisel-disked or no-tilled. Winter wheat was planted following the harvest of soybean, and shoots and roots were collected at tillering, jointing, heading, and ripening. Spores of AM fungi were isolated from soil collected at the beginning and end of the growing season. Spore populations and colonization of winter wheat roots by AM fungi were higher under low-input than conventional agriculture. Mycorrhizal fungus colonization occurred at low levels in the tillering stage and increased with plant development. Colonization during the jointing stage was higher in the low-input, no-tilled than in low-input, chisel-disked plots. Spore populations of the Glomus occultum-type group were more numerous in no-tilled than in tilled soil. The nutrient-use efficiency (g of plant biomass per g of plant N or P) of winter wheat depended on plant developmental stage, with a tendency for higher efficiency of the low-input plants at early growth stages, and of conventionally managed plants at more mature stages. Overall, plants grown in chisel-disked plots had higher N and P utilization efficiencies than plants grown in no-tilled plots. Final yield of grain was significantly greater in conventional than low-input plots, especially for no-till, despite the larger population of AM fungi.

Control of agricultural policymaking by the “agricultural establishment” has been challenged by a wide range of interests concerned with the externalities of modern industrialized agriculture. An “externalities/alternatives” or “ex/al” coalition appears to be an emerging force in agricultural policy debates. We surveyed three alternative agriculture groups, three conventional agriculture groups, and a statewide sample of farmers to learn whether each category forms a distinct, unified interest group whose perspectives on agricultural policy diverge substantially from the others'. There is considerable similarity among the alternative agriculture groups and among the conventional agriculture groups, the differences between them being much greater than the differences within each category. The statewide farmer sample is generally intermediate between the two sets of interest groups, but is closer to the conventional perspective on most issues.

U.S. agriculture, which has developed in a mixed environment of private initiative and government support, is very successful by many measures. American farmers produce record levels of food and fiber per farm worker at very low budgetary cost to consumers. Recently, however, concern about resource depletion and agrichemical pollution has caused critics to question the environmental sustainability of the agricultural production system. Furthermore, pressures to trim the growing contribution of agricultural subsidies to the national budget deficit have led legislators and others to question the sustainability of the federal farm programs. Low agrichemical input or sustainable agricultural practices, such as nitrogen-fixing legumes in rotation with cereals, could reduce environmental damage. The selectivity and structure of historical farm programs, however, have economically favored conventional systems. Farm programs subsidize only about half the total value of agricultural products. Feed and food grains, cotton, and dairy products receive the lion's share of payments. Soil-building crops like forage legumes, most edible legumes, hay, and pasture are excluded. Secondly, the structure of commodity programs favors intensive production of program crops supported by high fertilizer and pesticide applications. This incentive emanates from the policy of computing the farm-wide deficiency payment for a program crop proportionately to the farm's historical “base” acreage and “established” yield for the crop. The leading farm program crops of corn, wheat, cotton, and soybeans occupied slightly over 60 percent of cropped acres and received at least 65 percent of all U.S. agricultural pesticides and fertilizer in the mid 19809s. Despite budget pressures and environmental concerns, near term termination of farm programs or decoupling them from production of particular commodities is unlikely. Fears about aggravating financial stress, reducing land values, and harming agrichemical supply businesses in program crop-growing regions will promote cautious incremental change. Recent promising signs of “creeping decoupling” include the 1986 freeze on established yields, the gradual reduction in target prices, the permitting of multi-year grass or legume plantings as set aside acreage, and the loosening of base acreage restrictions within the 1988 Drought Relief Bill.

I reexamined five previously published studies that compared the economics of high input conventional crop production systems in various regions to the economics of lower input alternatives that use green manures, cover crops, and more diversified rotations, but no inorganic fertilizers and little or no synthetic pesticides. The original analyses were extended to include estimates of each production system's contribution to the local economy, both directly through farmers' payments for labor and interest, and indirectly through the payrolls and profits of enterprises serving farmers. A similar comparison was also made for high input irrigated and lower input nonirrigated corn production. On a per acre basis, the high input systems' local economic benefits were equal to or greater than those of the lower input systems. However, they were lower as a fraction of total value of production in all but one case, since production was always higher for the higher input systems. Correspondingly, with all but one of the higher input systems, a greater portion of the value of production left the local economy to pay for purchased inputs. This becomes significant if the production system is not sustainable, so that the total productive potential of the area's agricultural resources is finite when integrated over their entire economic life. In such circumstances, the results imply that under the conventional system the local economy will capture a smaller share of the total productive value of those resources.

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.

The nutrient composition of swine excreta can be altered by manipulating the composition of the pig's diet Several approaches are reviewed: feeding according to the pig's growth phase, formulation according to the feed's digestible amino acids, use of crystalline amino acids, the ideal protein approach, formulation according to available phosphorus, and the addition ofphytase enzymes. Each has the potential to lower nitrogen or phosphorus excretion levels. Together they can dramatically reduce the nitrogen and phosphorus concentration of swine manure, which could be a major advantage in regions with a high density of swine or for swine operations with limited access to arable land. However, the value of the swine manure would be much less as a fertilizer because these two elements are important plant nutrients.

Farm programs influence the profitability of a crop rotation through five effects: (1) a deficiency payment (DP) effect, (2) an acreage reduction (ARP) effect, (3) a base effect, (4) a crop price effect, and (5) a risk reduction effect. This study initially examines ARP and DP effects of the 1985 Farm Bill on the relative profitability of a low-input rotation and a grain-intensive conventional rotation in Washington state over 1986–1990. In years of low deficiency payments or high foregone returns from ARP land, the low-input green manure rotation was competitive with the conventional rotation but lost its advantage in years of low ARP costs or high deficiency payments. Long-runincentives to maintain wheat base introduced a consistent bias against the low-input green manure rotation. Planting flexibility options proposed during the 1990 Farm Bill debate could reduce farm program barriers to green manure and other low-input rotations. The Bush Administration's Normal Crop Acreage (NCA) proposal, which was not accepted in the 1990 legislation, would have largely eliminated base erosion for the green manure rotation in this study. More importantly, non-ARP green manure acreage would have qualified for deficiency payments under the NCA, thereby sharply increasing the low-input rotation's relative profitability. Proposals like the NCA might receive further attention in the future due to environmental concerns, fiscal pressures, or possible trade agreements requiring multilateral phaseout of agricultural subsidies coupled to commodities.

Sustainable production systems are needed to maintain soil resources and reduce environmental contamination on erodible lands that are incompatible with tillage-intensive operations. A long-term cropping systems comparison was established at Beltsville, Maryland, on a site with 2 to 15% slope to evaluate the efficacy of sustainable strategies compatible with reduced-tillage systems. All systems followed a 2-year rotation of corn the first year and winter wheat followed by soybean the second year. Treatments included (1) no-tillage system with recommended fertilizer and herbicide inputs, (2) crownvetch living mulch system with similar inputs to the no-tillage system, (3) cover crop system including a hairy vetch cover crop before corn and a wheat cover crop before soybean with reduced fertilizer and herbicide inputs, and (4) manure system including crimson clover green manure plus cow manure for nutrient sources, chisel plow/disk for incorporating manure, and rotary hoe plus cultivation for weed control. Results from the initial 4 years demonstrated the relative productivity of these systems. Corn yields were similar in the no-tillage and cover crop systems in each year; both systems averaged 7.8 Mg ha-1 compared to 5.7 Mg ha-1 in both the crownvetch and manure systems. Wheat yields were highest in the manure system in the first 2 years and in the crownvetch system in the last 2 years. Soybean yields were highest in the cover crop system in all years. The manure system usually had lower yields than the highest yielding systems, partly because of competition from uncontrolled weeds. Several measures of the efficiency of grain production were evaluated. The no-tillage system produced the most grain per total vegetative biomass throughout the rotation. The cover crop system produced the most grain per unit of external nitrogen input and, along with the no-tillage system, had the highest corn water-use efficiency. The cover crop system also recycled the most vegetative residues and nutrients of all systems. No single system performed best according to all measures of comparison, suggesting that trade-offs will be required when choosing production systems.

Interest in the cultivation of goldenseal is increasing and this may have benefits for agriculture, human health, and conservation. To enable a better understanding of growing conditions, cultivation methods reported in the literature were reviewed, 21 natural goldenseal populations in the northern portion of its natural range in North America were described and analyzed in terms of population size and health, and 15 successful growers were interviewed on requirements for optimal cultivation. Growing conditions in the wild were compared to those reported in the cultivation literature. Summary of data from natural populations suggests goldenseal grows best in mixed hardwood forests, under 60–65% shade, in moist sandy loam soils high in organic matter, with pH 5.7 to 6.3. Similarly, review of the literature suggests that goldenseal grows best in moist, well-drained loams high in organic matter, with pH 5.5 to 6.5. Reported shade requirements vary but 47–80% shade is considered optimal. Growing conditions reported by growers were also consistent with the cultivation literature and similar to conditions of wild populations. Although optimal growing conditions are similar to those for many crops, goldenseal is relatively robust and can grow well in a variety of conditions including wet, predominantly sandy or clay soils with pH as low as 4.8 and as high as 7.8. Cultivation can utilize a ginseng crop infrastructure and goldenseal has been recommended as a rotation crop for ginseng. Commercial production of goldenseal is potentially advantageous because (1) it is an environmentally friendly crop; (2) it has been grown successfully far outside its natural range, is easy to grow, and is considered potentially profitable; and (3) it is relatively inexpensive, having low energy, land area, and fertilization requirements. Development of a sustainable crop may contribute to the protection of native wild germplasm, which can provide valuable material for crop improvement.

Farming systems are often complex elaborations of the human societies to which they belong, with many traditional and social implications. Untangling the main social and structural constraints may improve productivity without an increase in environmental costs. Integration of cereal and sheep farming throughout the Mediterranean basin has been traditional. Mutually beneficial relationships between the sheep industry and cereal farming, and the vital role of forage legumes in meeting the modest needs of sheep for nitrogen, are stressed. This agropastoral system, however, is endangered in central Spain mainly because the pastoralist (sheep owner) is land-less, while the cultivator (land owner) has little interest in enforcing the law; fees for grazing rights are very low. Farmers, particularly young farmers, reject the current sheep operation because of the harsh working conditions. Restructuring of the grazing system would require a new policy scenario that would link European Union farm subsidies to structural reforms and would stress cooperative behavior.

The red sunflower seed weevil, Smicronyx fulvus LeConte, is a major pest of sunflower in North and South Dakota and Minnesota. Typically, insecticides are used to reduce oviposition and prevent economically damaging larval populations from developing. In a test of a reduced-pesticide alternative, we planted early maturing sunflower in the margins around commercial fields of oilseed sunflower. The margins flowered earlier than the field interiors and acted as a trap for the red sunflower seed weevil. They were treated with an insecticide while the trap rows were blooming and before the field interior began to flower. Conventional fields entirely treated with insecticide served as checks. We compared the trap and check fields with regard to yield, the fraction of larval-damaged seeds, and economic costs (insect damage and the cost of insecticide materials and application). Yield and larval damage of seeds were comparable between check and trap fields. However, the economic costs of weevil control in the check fields was greater than in the trap fields. Trap cropping is a recommended strategy for the red sunflower seed weevil, especially where economically damaging populations of the weevil are expected.

Alternative agriculture can be viewed as an alternative belief system to that underlying conventional agriculture. However, alternative agriculture can also be viewed from a technological perspective—that is, as a set of substitute technologies to conventional agriculture from which a farmer can selectively choose. Definitional distinctions between low-input, organic, sustainable, and conventional agriculture become important with this second perspective. Different policy and research implications are generated from these competing perspectives.

The conversion from high to low input agricultural systems has been studied at the field and farm scale but analysis of the effects of conversion at the landscape or regional scale has not previously been attempted. In this paper, we apply existing historical data bases on changing inputs and changing land uses to project possible effects of conversion on productivity and environmental quality on the landscape scale. We chose two areas for the analysis of changing input effects on landscape structure and function. One area is a region defined as the southern half of the lower peninsula of Michigan (Southern Lower Michigan or SLM). The second area is a small watershed, Watershed K of the Little River Watershed, in the Gulf-Atlantic Coastal Plain of Georgia. In SLM, land use data suggest that lower input use will lower per hectare productivity, and that regional production can only be maintained by bringing marginal lands into production. The prime lands not already in crop production in SLM are mostly poorly drained or sandy soils which will require either drainage modifications or supplemental irrigation for crop production. Intensification of input use in SLM during the last 20 years has led to increases in aggregate production, but may have contributed to declining water quality in the Grand River, the major drainage of that region. On Watershed K, corn grain yield was linearly related to N fertilizer application. A hypothetical yield response curve with a yield of 1500 kg/ha of corn grain without nitrogen fertilizer was selected for use in the analysis of changing inputs. Land use data on Watershed K showed that even with no nitrogen input to corn, the aggregate production of corn could be maintained without encroachment on riparian areas which are critical to maintenance of water quality. Our analyses, which are limited to historical data on the relationships among input, yield, and environmental quality, raise many questions about the landscape scale effects of conversion from high to low input systems. Relationships between inputs and yields are poorly understood at the field scale and relationships among inputs, productivity, and environmental quality have not been established at the landscape scale. Our analyses also raise questions about the need to maintain aggregate landscape production in the light of crop surpluses and declining environmental quality.

Five thoughts about the role and future of weed science in agriculture are analyzed. Much about the tools, techniques, and achievements of weed science should be lauded. Its achievements in basic science and its worldwide contributions to agricultural production and productivity are incontestable. The discipline has been based primarily on chemical technology, and the weed science community has been shaped by the available technology and by the purposes of its members. New, sustainable weed management systems will rely on knowledge derived from answers to new questions about weed-crop relationships and management techniques. As weed scientists develop better management systems, they will need to find better words to describe what they do and why it is important.

Nitrate contamination of surface water resulting from inputs of agricultural drainage water is a widespread problem. To learn whether alternative agricultural practices might ameliorate this problem, we measured NO-3 in water draining from three neighboring fields from 1970 to 1992. Drainage water from two fields fertilized with N exclusively as composted and liquid manure had NO-3 concentrations less than 2 ppm (20% of the Public Health Service recommended limit for drinking water). When these fields were converted to a corn/soybean rotation fertilized with anhydrous ammonia, NO-3 concentration increased about 7- to 10-fold. On a third field, corn was always fertilized with anhydrous ammonia. Changing this field from a rotation of corn, oats and hay to corn/soybean and increasing the rate of N fertilization by about 18% almost doubled the NO-3 concentration in the drainage water. The corn/soybean rotation most prevalent in the Corn Belt today resulted in high NO-3 concentrations in the drainage water, while the alternative system prevented NO-3 problems.