Location: Soil Dynamics Research2010 Annual Report
1a. Objectives (from AD-416)
Develop conservation tillage systems for vegetable production that (1) implement weed management regimes, including cover crops, compost, and mulching; (2) evaluate the biological and economic outcomes of the different systems; and (3) promulgate technology transfer through demonstrations/Field Days and publications for area farmers and agricultural professionals.
1b. Approach (from AD-416)
Specific methods include the following: conservation tillage systems and crop rotations to disrupt weed cycles and enhance competitiveness of crop plant through additions of N-fixing cover crops, such as crimson clover and hairy vetch, planting competitive crop varieties to maintain suppression of weeds, reducing weed seed set through allelopathic effects from crops, such as rye and oats, and improving the advantage of crops over weeds through compost based fertilizer applications. The experimental design includes two main plot treatments (No cover crop and cover crop) and three weed control subplot treatments that include mechanical weeding, herbicide, and mulching. Sweet potato will be tested in rotation with selected high values vegetable crops adapted to the southeastern environmental conditions. A farmer in Macon County has been selected to participate in this research and demonstration project. County extension agents, Tuskegee University researchers, and USDA/ARS scientists will collaborate and provide technical assistance to the farmers and help in disseminating research findings.
3. Progress Report
In May 2009, cover crops were cut and left on the soil surface (conservation tillage) or cut and incorporated into soil by tillage (conventional tillage). A strip tiller was used to break the hard pan and loosen the soil in the seed bed (conservation tillage treatment); sweet corn was planted for 90 days. The cover crop treatments included black oat alone, crimson clover alone, hairy vetch alone, black oat + crimson clover, and black oat + hairy vetch. Sweet corn yields in the first year were consistently higher under conventional tillage (7.36 Mg ha-1) compared to no-till plots (6.86 Mg ha-1). The highest sweet corn yield was obtained when sweet corn was preceded by black oat in the conventional tillage system (10.2 Mg ha-1). Tuskegee University conducted two separate workshops to train extension agents and area farmers interested in sustainable agriculture. The project team, selected Auburn University faculty, and USDA-ARS National Soil Dynamics Laboratory partners participated as resource personnel during training sessions. The workshops focused on cover crop adaptation to southeastern environmental conditions. Farmers and extension agents participating in the workshops visited field experiments at the George Washington Carver Agricultural Experiment Station. Factsheets were published to help area farmers to better understand the role of cover crops in crop rotation.