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Our primary objective is to integrate the advances that we have made on sod-based rotation and strip tillage into organic systems for vegetable production in the Southern Coastal Plain. Our methodologies are based on the long term enrichment of soil characteristics, which is also a requirement for any successful, sustainable organic system. Experiments will be designed so that these technologies can be compared directly to alternative techniques currently being used for organic production in the Southern Coastal Plain. We will assess each of these techniques from a production, as well as an environmental standpoint. Adoption of these systems will promote land stewardship practices designed to rejuvenate depauperate soils.<p> Objective 1. Experimental Design. To develop and implement a system of organic vegetable production based on: 1) sod-rotation (2 year rotations of bahiagrass), and; 2) strip-tillage for vegetable crops in the Southern Coastal Plain. A 2 x 2 split plot design will be used so that each technique (sod-rotation and tillage) can be compared. <p>Objective 2. Production and Profitability. To evaluate each component (sod-based rotation and tillage) of the system in terms of productivity (plant biomass, yield, fruit quality, plant physiology), and pest impacts (arthropods, pathogens, nematodes and weeds). Enterprise budget will be constructed. <p>Objective 3. Ecological Impacts. To evaluate each component (sod-based rotation and tillage) of the system in terms of ecological impact with emphasis on soil conditioning (soil carbon sequestration, soil organic matter, and soil moisture retention), and water quality. Chemical analyses of plant material and ground water will also be conducted and budgets can be constructed to fully examine the effects of treatments on carbon, nitrogen, and water budgets in these systems.<p> Objective 4. Outreach. We will establish an effective outreach program to disseminate knowledge about these techniques to those interested in organic production. <p>The proposed project activities are intended to have the following anticipated outcomes: 1) Conventional and limited resource farmers will gain knowledge and skills to incorporate organic production and marketing as viable alternatives to farm operations; 2) Development of an effective outreach and education model for introducing organic production and marketing to limited-resource audiences; 3) Use of Farmers' markets by all targeted sectors will increase; 4) Acreages of organic production will increase; 5) Local availability of organic produce will increase; 6) New markets for limited resource farmers will be developed; 7) New organizations of organic growers of all types will be implemented, and; 8) Publicity of the accomplishments and the application of the results will be presented, and extramural funding leveraged by the strategic rotations will increase dramatically.
Non-Technical Summary: Soil conditioning is a core tenet of successful organic production. Rotational systems for this purpose have been successfully implemented nation-wide contributing to the 15% annual increase in organic production for the last decade. However, comparatively few systems have been utilized within the Southern Coastal Plain of Florida, Georgia and Alabama which provides the majority of fall/winter vegetables for much of the US. These states have less than 0.3% of the national acreage for organic production. Poor soils, high temperatures and humidity pose unique regional problems. Over the last decade we have developed and tested rotational and tillage systems that are highly amenable to incorporation into organic production. Sod rotations including 2-year plantings of bahiagrass have repeatedly been shown to increase soil carbon and water retention, reduce fertilizer and irrigation inputs, and produce higher yields for a variety of crops. We have also shown that strip tillage coupled with cover crops further enhances soil carbon sequestration, organic matter and moisture retention. Our long growing seasons allow year-round conditioning of the soil, and potentially expedite transition from conventional to organic systems. Moreover, the high ability of bahiagrass to sequester both carbon and water are in concert with responsible land stewardship. We will test the effects of these rotational and tillage systems for organic vegetable production in the Southern Coastal Plain. Crop rotations and tillage will be evaluated on an ecological level (carbon sequestration, plant biomass, and carbon, nitrogen and nutrient partitioning, water usage), plant (yield, fruit quality, etc.) and economic level. <P> Approach: The following systems will be compared: 1) Winter cover crops (oat/rye mix) followed by conventional tillage prior to planting and as needed on a spring green bean crop followed by soybeans in the summer as a green manure crop followed by a fall broccoli crop; 2) A field that has had bahiagrass for two year will be turned and planted to winter cover crops (oat/rye mix) followed by conventional tillage prior to planting and as needed on a spring green bean crop followed by soybeans in the summer as a green manure crop followed by a fall broccoli crop; 3) Winter cover crops (oat/rye mix) followed by strip tillage into rolled down cover crops in the spring prior to planting green beans which will be harvested. Soybeans will be no tilled drilled into the greenbean stubble as a nitrogen producing crop for the strip tilled fall broccoli crop; 4) A field that has had bahiagrass for two year will be turned and planted to winter cover crops (oat/rye mix) followed by rolling the cover crop and strip tilling green beans into them for harvest. Soybeans will be notilled drilled into the greenbean stubble as a nitrogen producing crop for the strip tilled fall broccoli crop. Systems 1 and 3 and systems 2 and 4 can be compared for tillage effects and systems 1 and 2 and systems 3 and 4 can be compared to the impacts of rotating perennial grass through vegetable land. These plots will will be monitored for ecosystem function and farm economics. All treatments will have green beans (spring) and broccoli (fall) as cash crops. The four rotation treatments will be set up on organically-certified land at the NFREC-Quincy. After initial plot layout, we will collect baseline data on the plots. The weeds species and densities will be assessed. Plant mesurements include stand density, fruit quality, yield, net photosynthesis, stomatal conductance, and leaf nutrient analyses. Pest management will include OMRI-approved organic pesticides such as Matran, BT and Entrust. The population of athropods,nematodes, soil microbes and plant pathogens will be examined every two weeks. The physical (bulk density, particle size distribution, soil water status, wet aggregate stability), chemical (Kjeldahl N, extractable soil nutients) and biological (organic matter) properties will be examined. Plant and soil data will be used to construct carbon, nitrogen and water budgets for the four rotation treatments. We will perform a complete economic budget using enetrprise budgets. Community level analyses on arthropods (herbivores and predators), pathogens, nematodes, soil microbes and weed species will consist of diversity indices and principle component analyses to determine significant factors and relationships of plot factors to fauna populations. We will track the individual treatment plot variables over the course of the rotations and expenditures such as fuel, etc. will be recorded by plot. Outreach will comprise extension venues of field days, presentation at grower meetings, county agent in service trainings, web site postings, and presentations at professional and grower meetings.