Comparison of Organic Farming Systems Using Off-Farm Nitrogen with - without Animals
The objectives of this project are to evaluate the sustainability of organic farming systems that rely on biologically-fixed nitrogen versus those using off-farm nitrogen to maintain cropland, and to compare the production, soil quality, and environmental impacts of crops-only organic farming systems with systems integrating crops and livestock. The project continues one begun in 1999 when the West Virginia University Horticulture Farm underwent the transition to organic practices. Replicated field trials in vegetable (market garden) and field crops were established using a randomized factorial design. Plots receiving compost will be amended with compost to supply 150 pounds nitrogen per acre each year to enhance soil fertility. A four-year crop rotation is being maintained in both market garden and field crop farming systems. In addition, in the field crop system, livestock production (sheep and poultry) and pasture are being integrated into half of the field crop systems. Results are being communicated to growers, extension staff, and the public through field days, internet web pages, and other media outlets.
The overall objective of the project is to compare organic farming systems using biologically-derived nitrogen (legumes) with systems using nitrogen from off-farm composted manure. Soil quality, pest impacts, yields and economic performance are being measured and results are being communicated to growers.
Specific performance targets include:
1. Ten growers identified from our grower advisory committee, attendees at Farm Field Days, or commodity organizations, will base, at least in part, their compost use rates on soil quality and economic performance criteria developed from this phase of the project.
2. The proportion of growers that are transitioning from conventional to organic production that have incorporated research and cost-benefit results in their decision-making in designing a transition system for their operation will increase to 50 %.
3. Nine undergraduate students will be trained in organic farming practices through internships. Farm-related experience will be provided to additional undergraduate and graduate students through work experience, research opportunities, field days, and classroom and non-classroom activities.
4. Five growers per year, identified at field days and through direct contacts, will participate in on-farm evaluations/demonstrations of selected practices in the following year. These selected practices will include: use of barriers (row cover, particle film sprays, etc.) for pest management; rotation practices, diversification through integration of livestock into the farming system, and weed management using mulches.
5. Twelve producers will incorporate practices for management of internal parasites in sheep using either rotational grazing and/or alternating sheep and poultry on pastures.
Data analysis from the first three years of the farming systems evaluations is underway. Poultry production will be integrated with the existing sheep/crops production system in summer 2003. Small plot trials to evaluate pest management practices and compost application rates will be modified to refine treatment comparisons. New weed management alternatives are being evaluated and compost application rates will be modified as high rates begin to saturate nutrient holding capacity of soils.
Three undergraduate student interns are being enrolled for the 2003 field season and will work in soil monitoring, horticultural production and crop/livestock systems integration. The 2003 Field Day for growers is scheduled for August 7 and will feature demonstrations, research tours, and hands-on workshops.
Five growers are being solicited, from a pool of applicants collected at the last field day, to participate in on-farm evaluations of organic management practices. Rotational grazing of sheep with poultry will be evaluated to continue maintaining sheep with low intestinal parasite burdens. (Although rotational grazing is successful in preventing problems with intestinal parasites, the short pasture rotation periods require very strict attention to management, thus alternating poultry with sheep grazing may simplify management needs while more fully utilizing pasture forage production).
Impacts and Contributions/Outcomes
Production performance for organic farming systems will be demonstrated and evaluated for the next three years, allowing complete evaluation of the four-year crop rotation sequence. Grower participation at field days and in on-farm application of management practices has increased and student participation in the project is resulting in an increasing pool of trained practitioners. Scientific papers reporting results from the project were presented at meetings of the International Federation of Organic Agriculture Movements (IFOAM), the American Phytopathological Society, and the Agronomy Society of America (Northeast Branch). Fact sheets are in preparation, with assistance and support from the West Virginia University Cooperative Extension program.