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Viability of Alley
Cropping Project Team
Rationale/Background Organic farming is an important alternative to farming systems that employ chemicals potentially damaging to health and the environment. Three major problems need to be solved before organic farming can be more widely adopted: 1. Expense: Collecting, preparing, and spreading organic amendments is expensive in terms of both cash and labor; 2. Tilling: Almost all organic farmers till their soil, thereby destroying the very resource (soil organic matter) that is most essential for healthy, vigorous crops; 3. Weeds: Weed control without using herbicides (not permitted in organic farming). The goal of this project is to develop agroforestry techniques that will help solve these problems. Approach We have established a system of agroforestry/organic farming that has the potential to overcome these problems of organic farming. It is based on an irrigated alley cropping system with leguminous hedgerows. In the fall, a winter cover crop of rye and clover is planted in the alleys. In the early spring, the cover crop is knocked over and killed with a "roller-crimper" which flattens and kills the cover crop. Then a crop is planted into the mulch with a no-till seed planter or no-till vegetable transplanter to avoid oxidation of soil organic matter that occurs with conventional cultivation. The mulch suppresses weeds for approximately 6 weeks, at which time the hedgerow species is ready to be pruned. The prunings supply additional nutrients and provide further weed control. Because the hedgerows are in direct proximity to the cropped soil, the expense of collecting and spreading organic matter is greatly reduced. In the fall after harvest, a winter cover crop is again planted with a no-till seed drill. Results Several Ph.D. and M.S. research projects are being carried out on this system: 1). a food chain model of the nitrogen dynamics in the alley cropping system, that should enable us to synchronize addition of prunings to match plant demand; 2). a study of competition between hedgerow species and crop species – results show that there is competition for moisture under non-irrigated conditions, but not for nutrients; 3). a study of the contribution of root sloughing to soil fertility – results suggest that roots are sloughed as a result of above-ground pruning, and that these roots make a significant contribution to soil fertility; 4). a study of the efficacy of various winter cover crops to contribute to soil fertility and suppress weeds – preliminary results suggest a combination of winter rye and clover is most effective; 5). tests have been carried out on various hedge-row species [Albizia julibrissin, (mimosa) Amorpha fruticosa (false indigo) and Alnus serrulata (alder)]. A. julibrissin and A. fructicosa are the most productive and have the highest nitrogen content, but A. serrulata decomposes more slowly and thus is more effective a suppressing weeds. The CSTAF site is seeing increasing use as a center for outreach and extension. Over 1,000 students from the University of Georgia used the site for laboratory exercises during the past year. In 2003, the University of Florida received a grant to establish a distance education and field course in agroforestry. Our research farm is the site of the field courses. The first course is scheduled for three full weeks in May, 2004. Twenty students are enrolled for the course. The course will be taught again in the fall of 2004 as a regular semester course. The grant will support these courses for two additional years. At the May 2002 meeting of the Board of Directors of CSTAF, a suggestion was made that we should begin working toward organic certification. We have hired an experienced organic farmer who is using the alleys between the hedges for organic plots. He is working toward organic certification.
Work planned for the remainder of the CSTAF grant The three students (two Ph.D., one M.S.) working on the above-mentioned research projects will begin to analyze their data and prepare their thesis and dissertations. The long-term scientific objectives of the overall project are: 1. to use economic cost/benefit analyses to determine if alley cropping indeed has the potential to make organic farming more efficient; and 2. to use cost/benefit analyses that include environmental factors to compare organic farming with conventional farming. We now have the system in place to carry out these studies. We are preparing a proposal to The USDA Cooperative State Research, Education and Extension Service Competitive Grants Section, Integrated Organic Program, to continue development of this system, and work toward achieving the long-term scientific objectives. Publications/Outputs Refereed: Castellanet, C. and C.F. Jordan. 2002. Participatory Action Research in Natural Resource Management. Taylor and Francis, London. Jordan, C.F. 2004. Organic farming and agroforestry: Alleycropping for mulch production for organic farms of southeastern Unites States. Agroforestry Systems 61-62: In press. Jordan, C.F. 2002. Genetic engineering, the farm crisis, and world hunger. BioScience 52: 523-529. Moseley, W.G. and C.F. Jordan. 2001. Measuring agricultural sustainability: energy analysis of conventional till and no-till maize in the Georgia Piedmont. The Southeastern Geographer 41 (1) 105-116. Theses/dissertations: Green, E. 2002. Nutrient addition and crop yield of an alley cropping system in the Piedmont of Georgia. M.S. thesis, University of Georgia. Presentations: Faucette, B. and C.F. Jordan 2002. Compost use for erosion and sediment control in construction and development areas. Poster presented at SARE conference "On the Road to Sustainable Agriculture, October 23-26, Raleigh Durham, NC. Jordan, C.F. 2002. Organic farming with no-till cultivation and leguminous hedgerows for mulch. Poster presented at SARE conference "On the Road to Sustainable Agriculture, October 23-26, Raleigh Durham, NC. Jordan, 2001. "A no-till planter for small-scale organic farming" The Second Assembly of the Scientific Congress on Organic Agricultural Research. Nov. 4-5, 2001, Rock Hill, S.C. Jordan 2001. "The problem of no-till planting following a winter cover crop, on small scale organic farms." Georgia Organics Conference Augusta GA, Feb. 9, 10, 2001. |
