bluuebunny/crossref_metadata_2025_split huggingface dataset:
Weed seed destruction by arthropods and rodents in low-input soybean agroecosystems
Authors: Brust Gerald E. , House Garfield J. 
Published: October 2009

AbstractWeed seed consumption experiments involving comparison of rates of seed loss by seed feeders were conducted over a five-week period in low-input (no insecticide, low herbicide usage) conventional- and no-tillage soybean agroecosystems. Seeds of four broadleaf weed species (ragweed[Ambrosia artemisiifoliaL.], pigweed[Amaranthus retroflexusL.], sicklepod[Cassia obtusifoliaL.], and jimsonweed[Datura stramoniumL.]) and one grain crop species (wheat[Triticum aestivumL.]) were provided in a free choice design at densities of 10, 25, and 50 seeds/24 cm3. Approximately 2.3 times more seeds overall, and 1.4 times more large seeds as a group were consumed in notillage systems than in conventional-tillage systems. In our experimental low-input, notillage treatments, large ground beetles (Carabidae: Coleoptera) (15–25 mm) and mice preferentially fed on the larger seed species, while small carabids (< 15 mm), ants and crickets, fed almost exclusively on the smaller seed species. Carabid beetles were responsible for more than half of all seeds consumed. Laboratory and field studies indicated that ground beetles selectively consumed specific seed species. In conventional-tillage, ants were one of the dominant consumers of seeds, suggesting different patterns of resource partitioning in each tillage system. We suggest that selective feeding by arthropod seed feeders, in combination with their high number, could affect the species composition and possibly the abundance of weeds in low-input, no-tillage agroecosystems.
Biological control and holistic plant-health care in agriculture
Authors: Cook R. James 
Published: October 2009

AbstractBiological control is defined broadly as the “use of natural or modified organisms, genes, or gene products” to reduce the effects of pests and diseases. Physical control is the use of tillage, open-field burning, heat-treatment (pasteurization), and other physical methods, usually to eliminate pests or separate them from the crop. Chemical control is the use of synthetic chemical pesticides to eliminate pests or reduce their effects. The many approaches to biological control can be categorized conceptionally into 1) regulation of the pest population (the classical approach), 2) exclusionary systems of protection (a living barrier of microorganisms on the plant or animal that deters infection or pest attack), and 3) systems of self-defense (resistance and immunization). The agents of biological control include the pest- or disease-agent itself (sterile males or avirulent strains of pathogens), antagonists or natural enemies, or the plant or animal managed or manipulated (immunized) to defend itself. The methods range from 1) conserving and making maximum use of indigenous (resident) biological control through cultural practices, 2) making one-time or occasional introductions of genes or natural enemies that are more or less self-sustaining and 3) making repeated introductions of a biocontrol agent (e.g. a microbial pesticide). Biological, physical, and chemical treatments and pest controls can be integrated into holistic plant-health care also known as integrated crop and pest management. Eight principles of plant health care are offered: 1) know the production limits of the agroecosystem; 2) rotate the crops; 3) maintain soil organic matter; 4) use clean planting material; 5) plant well-adapted, pest-resistant cultivars; 6) minimize environmental and nutritional stresses; 7) maximize the effects of beneficial organisms; and 8) protect with pesticides as necessary.
Use of organic amendments to increase the productivity of sand and gravel spoils: Effect on yield and composition of sweet corn
Authors: Hornick Sharon B. 
Published: October 2009

AbstractCrops grown on sand and gravel spoil areas are subject to temperature, moisture, and nutrient stresses due to the infertile, acidic, and coarse-textured properties of the spoil material. Additions of organic materials such as feedlot manure and sewage sludge compost applied at rates of 40, 80, and 160 Mg/ha were found to improve these spoil areas by providing (1) a more favorable pH for seedling germination and root development, (2) essential crop nutrients, and (3) a greatly increased water content of the spoils in the treated plots compared to fertilized controls. The manure-treated spoil plots had a higher water content than either the compost-treated spoils or the limed and fertilized control plots. In a drought year when the wastes were reapplied, both grain and stalk yields of sweet corn were highest for the manure-treated plots. The low heavy metal content makes these organic materials safe for use as soil conditioners. In addition, uptake and accumulation of toxic metals by sweet corn is generally less than other crops. The interaction between the kind and rate of organic amendment applied, the amount of rainfall in any given growing period, and the water content of the treated spoils determined the final nutrient composition of the stalks, leaves, and grain, as well as the grain and stalk yield.
Using crop diversity to manage pest problems: Some California examples
Authors: Flint Mary Louise , Roberts Philip A. 
Published: October 2009

AbstractModerate to large scale California growers (as well as small scale ones) manipulate cropping patterns in a number of ways to reduce pest problems. Crop rotation, which can be defined as diversifying crops over time, is used to manage selected pests, primarily weeds, pathogens, and nematodes. As a substitute for pesticides, crop rotation has been most rewarding in the control of nematodes; sugarbeet cyst and root knot nematode examples are detailed. Some pests that invade fields from nearby areas can be managed by modifying adjacent cropping patterns or practices; Pierce's disease of grapes, sugarbeet yellows and border harvesting of alfalfa are given as examples. Finally, multiple crops can be grown within a single field or orchard. Although this approach is not widely practiced by many California growers, two examples of systems where intercropping has been shown to limit pest numbers without the use of pesticides are described: intercropping of cotton with alfalfa and companion planting oats when seeding alfalfa. These examples show that using crop diversification to manage pests is feasible, but growers must be strongly motivated to make the necessary changes in cropping patterns. Most of the systems that have been widely adopted are those for which few other economically feasible methods were available.
An analysis of the California market for organically grown produce
Authors: Franco Jacques 
Published: October 2009

AbstractThe market value for organically grown produce in California was estimated to be at least 54 to 68 million dollars at wholesale prices in 1987. This market is rapidly growing. A 41 percent increase in the value of organically grown produce was observed in 1987. When this analysis was completed in early 1988, it was estimated that the wholesale value of the market could exceed $300 million by 1992. A sample analysis of 1986–1987 price and volume for organically grown broccoli showed relatively steady prices and a volume increase of over 50 percent, indicating a similar growth in market demand. Prices for organically grown produce are significantly higher than for conventional produce; however, in spite of high weekly volume volatility, organic prices appear to be less volatile than prices for conventional produce. This paper proposes that the collection, reporting, and analysis of organic produce market data be continued and improved and that new sources of data be integrated to ensure continued availability of timely market information. Availability of more market information should increase efficiency and aid the development of the organic produce industry. The paper also proposes that overall trends in the organic produce industry be systematically monitored by Federal-State Market News and that the increased use of market information by organic growers, growers considering the transition, and other interested parties in the industry be promoted.
Converting stewardship values into policy: The mission of the 1990 Farm Bill
Authors: Kroese Ron 
Published: October 2009

AbstractFarmers committed to the overall goal of sustainability in agriculture have banded together to support legislative action favorable to that goal. Specific objectives relate to addition of organic amendments to soils to improve fertility, avoidance of excessive use of pesticides and synthetic fertilizers, crop rotation, species diversity among crops, protection of wildlife habitats, and support of family-operated farms. Currently applicable legislation is believed to be unfavorable to some of these objectives and needs modification.
Trees and Sustainable Agriculture
Authors: Schaefer Peter R. 
Published: October 2009

AbstractIn the United States, trees constitute an element in agriculture whose importance has been inadequately appreciated. In actuality, they are highly important in several ways. From the time of the earliest settlements, they have served as a source of building materials and energy. They protect the soil against erosion by wind and water. When used as windbreaks adjacent to crop fields, they protect crops against the damaging effects of wind on crop yields. As windbreaks for livestock, they increase feed conversion efficiency, improve weight gains, and increase the survival rate ofnewborns. They provide habitat for wildlife and contribute aesthetically to the appearance of the countryside. They protect water resources. Trees need to have the story of their great benefits more widely and emphatically told.
Mechanical and cultural weed control in corn and soybeans
Authors: Gunsolus Jeffrey L. 
Published: October 2009

AbstractMany farmers and consumers are reevaluating chemical weed control because of the environmental risks of herbicides and their influence on farm size and diversity. This paper reviews research of the last 35 years on mechanical and cultural weed control in corn(Zea maysL.)and soybeans(Glycine maxL.).Soybeans can better use the weed control advantages of late planting and narrow row spacing and are less affected by early stand losses from mechanical weed control. In Minnesota, delaying planting to early June allows early germinating weeds to be controlled by preplant tillage but reduces the maximum yield potential of corn by approximately 25 percent and soybeans by approximately 10 percent. Narrow rows allow the crop canopy to close earlier, preventing emerging weeds from developing. However, in a nonchemical weed control system, the row spacing should allow for inter-row cultivation to control weeds that emerge with the crop. Up to a 10 percent reduction in crop stand may be expected in fields that have been rotary hoed. In Minnesota, a 10 percent stand loss results in a 2 percent loss of corn yield potential and no loss of soybean yield potential. Successful mechanical weed control is directly related to the timeliness of the operation. Rotary hoeing is effective on weeds that have germinated but not yet emerged but not on weeds that germinate from deeper than 5 cm, on no-till fields, or on fields with more than 20 to 30 percent crop residue. Inter-row cultivation is most effective on weeds up to 10 to 15 cm tall. Successful nonchemical weed control requires highly refined management skills and is as much an art as a science.
The potential for Swedish farms to eliminate the use of artificial fertilizers
Authors: Granstedt Artur 
Published: October 2009

AbstractThis paper discusses data on plant-nutrient conservation in Sweden between 1950 and 1980 and on plant-nutrient balances in conventional and alternative farming. The amounts of plant nutrients supplied in the form of artificial fertilizer in Sweden increased severalfold between 1950 and 1980. The amounts of N and P applied were four times higher than those recovered in agricultural products. This difference not only represents a loss to farmers but also a burden on the environment. This problem is a consequence of the increased separation of crop management from animal husbandry in Sweden. The flow of plant nutrients through the agroecosystem can be represented as follows: Artificial Fertilizers- > Crop Production-> Animal Husbandry- > Losses (air, water, or immobilization).This paper suggests that all farms in Sweden can operate effectively without relying on applications of highly soluble plant nutrients. By recirculating plant nutrients in manure and cultivating nitrogen-fixing species, the need for artificial fertilizers can be eliminated while minimizing nutrient losses and their associated adverse effects on the environment. Successful alternative farms provide practical examples of how a farming system can eliminate its dependence on applications of highly soluble plant nutrients by stressing effective nutrient economy and biological activity. The strategies they use include: matching animal management practices to the farm's own production of feed, thereby reducing net removal of plant nutrients per unit area (in Sweden 0.6–0.8 animal units per ha); minimizing nutrient losses through careful manure management and by using cover crops; and supplying N by nitrogen-fixing ley species, and P and K by soil weathering and by applying supplementary soil improvement materials.
Factors affecting the nutritional quality of crops
Authors: Hornick Sharon B. 
Published: October 2009

AbstractSeveral factors can directly or indirectly affect the nutritional quality of crops. Among these are soil factors, such as pH, available nutrients, texture, organic matter content and soil-water relationships; weather and climatic factors, including temperature, rainfall and light intensity; the crop and cultivar; postharvest handling and storage; and fertilizer applications and cultural practices. This paper deals primarily with fertilizer and cultural management practices, and on certain environmental factors that affect the nutritional quality of field crops and of fruits and vegetables. Earlier research that has investigated the nutritional status of crops grown with either chemical fertilizers or organic fertilizers is discussed. These studies often have given contradictory results on crop yields and on crops' mineral and vitamin contents. Other factors, such as maturity at harvest, postharvest handling and storage, anti-nutritive components, and residues of chemical fertilizers and pesticides are reviewed with respect to food safety and quality, and their implications for human and animal health. Future research needs are identified so that comparable results and valid comparisons can be obtained to identify the best management practices to ensure that food is safe and nutritious for the consumer.
A perspective on the economic impacts of reducing agricultural chemical use
Authors: Lee Linda K. 
Published: October 2009

AbstractAdoption of agricultural practices that reduce or eliminate chemical use creates tradeoffs among yields and output, production costs and net income at the farm level. If widespread adoption is to occur, potential improvements in human health and the environment from reduced chemical use must be weighed against effects on aggregate farm income and consumer food prices. At present, these tradeoffs are subject to considerable debate.I review available farm level and aggregate economic studies of reductions in total agricultural chemical use. At the farm level, available studies suggest that organic and low-input farming systems result in declines in per acre yields and in lower net returns than most conventional farming systems, although the studies do indicate that net returns for the two systems can be comparable under some conditions. Several studies suggest that low-input systems perform well with respect to risk criteria. I also discuss the potential influence of government programs on the profitability of some low-input farming systems.All aggregate economic models conclude that widespread adoption of organic farming would result in decreased yields, decreased aggregate output, increased farm income, and large increases in consumer prices. These models have limitations, however. Recommendations are made for further economic research of the impacts of reducing agricultural chemical use at both the farm and aggregate levels.
Research and agriculture: Challenging the public system
Authors: Danbom David B. 
Published: October 2009

AbstractThe publicly sponsored agricultural research system in the United States has always had to deal with the tension between public expectations and scientific practices and standards. The equilibrium it established between those two contradictory demands has been unraveling since the 1960s. The contemporary challenge to the system is to redefine its public and scientific roles in an environment of rapid scientific change and of public debate and disunity.
Biomass as an energy source for the midwestern U.S.
Authors: Keeney D. R. , DeLuca T. H. 
Published: October 2009

AbstractRecognition of the environmental costs of fossil fuels coupled with concern over their depletion within the next few decades has broadened the search for alternative energy resources, including biomass energy. Ethanol produced from corn (Zea mays L.) grain currently is the primary form of biomass energy produced in the Midwest, but its net energy balance commonly is negative when corn grain is produced under conventional practices. Reducing fossil fuel inputs, particularly for nitrogen fertilizer, will improve the energy balance, but more substantial improvements involve increased efficiency of ethanol production. An alternate source involves fermentation of crops such as sweet sorghum (Sorghum bicolor [L.]Moench).Other potential biomass energy resources for the Midwest include oils extracted from seed crops, methane from waste digestion, and combustion, gasification or fermentation of woody and herbaceous crops and crop residues. These resources may serve as an energy supplement or a useful energy source for individual farms, households or rural communities. Biomass energy systems in Midwest agriculture must be evaluated regarding their long term environmental impacts and their sustainability. Externalities that must be considered include surface and ground water pollution, soil erosion, and economic and social benefits to the rural community.
Economic and environmental considerations for nitrogen management in the mid-Atlantic coastal plain
Authors: Norris Patricia E. , Shabman Leonard A. 
Published: October 2009

AbstractA case study in eastern Virginia provides evidence that both environmental and farm profit goals may be satisfied by alternative nitrogen (N) management strategies for grain production. We used a linear programming framework with an N mass balance model to calculate returns from several options for providing N to crops. Replacing single applications of inorganic N fertilizer with split applications or with additions of organic N were found to reduce the potential for N loss from cropland and to increase net returns. For some N management strategiesy however, adoption may require financial and educational assistance. As a result, water quality policies may benefit by including such incentives.
Agricultural use of organic amendments: A historical perspective
Authors: Parr James F. , Hornick Sharon B. 
Published: October 2009

AbstractAgricultural research conducted in the United States since establishment of the U.S. Dept. of Agriculture and Land-Grant University System in 1862 has shown that regular and proper additions of organic materials are very important for maintaining the tilth, fertility, and productivity of agricultural soils, protecting them from wind and water erosion, and preventing nutrient losses by runoff and leaching. Several millennia earlier, Roman agriculturists were advocating crop rotations, green manuring, composts, legumes, farmyard manures, crop residues, wood ashes, seaweed, and sewage wastes for supplying humus and nutrients to restore or enhance soil productivity. Even earlier, Asian farmers also used these practices to maintain healthy and productive soils. Today the most serious problem in U.S. agriculture and agriculture worldwide is the widespread degradation of agricultural soils through erosion and the consequential decline in productivity. In view of how much information is available on the benefits of organic recycling on agricultural lands, one wonders why we aren't doing a better job of protecting and conserving our land resource base. We discuss strategies for using organic resources more effectively to achieve a more sustainable agriculture for the future.
Land use options on a semi-arid Alfisol
Authors: Das S.K. , Sharma Shriniwas , Sharma K.L. , Saharan Neelam , Nimbole N.N. , Reddy Y.V.R. 
Published: October 2009

AbstractFour land use options—annual cropping, agroforestry, agrihorticulture, and agrosilviculture—were tried on a Land Capability Class IVs Alfisol under rainfed conditions to find a farming system that would be profitable and sustainable. The agrihorticultural system required more cash input but gave a value/cost ratio of 2.16 compared with 1.95 with annual cropping, 1.69 with agroforestry and 1.52 with agrosilviculture. Runoff was 4.9% in the agrihorticultural system, and 10.6% with agroforesty. Economic and soil health considerations led to the conclusion that the agrihorticultural system would be a sustainable land use option for the semi-arid Alfisol However, other options also are profitable, with value/cost ratios of more than 1.50. Therefore, land users can choose among several systems, depending on their desired production level and their investment capacity.
Support in New England for certification and labelling of produce grown using integrated pest management
Authors: Hollingsworth Craig S. , Paschall M. J. , Cohen Nancy L. , Coli William M. 
Published: October 2009

AbstractWe surveyed a total of 549 Cooperative Extension clientele (consumers), farmstand owners, and food industry representatives in New England to assess the potential for certification and labelling of produce grown using integrated pest management (IPM). The survey elicited self-reported knowledge of IPM, perceptions of current pesticide use and IPM, and attitudes toward certification and labelling of produce as “IPMGrown.” The respondents expressed widespread support for certification and labelling of produce grown using IPM. Potential barriers to the marketing of IPM-labelled produce were also revealed. The survey showed the need for education to inform the public about pest management in agriculture and to build confidence in the safety of our food supply.
Barriers to low-input agriculture adoption: A case study of Richmond County, Virginia
Authors: Diebel Penelope L. , Taylor Daniel B. , Batie Sandra S. 
Published: October 2009

AbstractWe coupled a nonlinear mathematical programming model with sensitivity analysis and evaluated some economic barriers to adoption of low-input agriculture by farmers in Richmond County, Virginia. Collection of primary data made the model more realistic. We analyzed potential barriers to adoption, including poultry litter price, yields, labor requirements, and variable input costs. We found the adoption of low-input practices to be sensitive to the price of poultry litter and relatively insensitive to yields, labor requirements, and variable costs. However, when several of these barriers are combined, the model predicts that farmers would use conventional practices. Therefore analysis of the farm as a system rather than practice by practice is important when identifying the effects of economic barriers.