Alabama has some of the best fields for agriculture in the country due to ample rainfall, long growing season, and proximity to major urban markets. Considering the long-term drought in California, urban development and high land cost in central and south Florida, vegetable acreage in Alabama is projected to rise significantly in the next decade due to low production costs and long growing season for crops. However, one of the biggest problems with expanding vegetable production in Alabama and the Southeast is limited weed control options and tremendous weed pressure as compared to Midwest and northern U.S. Southern crabgrass, goosegrass, pigweed species, lambs quarter and nutsedges can outcompete plant growth early in the season, and reduce yield and harvest efficiency. Moreover, sensitive vegetable varieties can be easily injured by herbicides, and herbicides registered for vegetable production are generally limited as compared to agronomic crops. Considering limited herbicide options, strong market demands, high weed pressure and long growing season, weed control in vegetable production has been challenging in the Southeast, particularly in organic production.
To suppress weeds, increase soil temperature, retain moisture and prevent nutrient leaching, many vegetable farmers utilize plastic mulch in their production. However, initial installation costs, irrigation equipment and annual material costs are high. In some cases, direct seeding without plastic mulch may be easier to operate and more cost-effective as plastic mulch disposal and recycling are both financially and environmentally costly. To increase sustainability, biodegradable mulches have been developed since the 1980s but adoption rate is low due to high cost, inconsistent breakdown time, and lack of knowledge among farmers about the performance of biodegradable mulches. So far, little research and extension work has been done in the Southeast to evaluate the efficacy and economic viability of newer biodegradable mulches and to promote this option to vegetable farmers.
The proposed solutions to address the problems stated above include evaluating high-residue cover crops and biodegradable mulches for weed control in sustainable vegetable production.
Project objectives from proposal:
- Evaluating high-residue cover crop systems plus reduced tillage for weed suppression and reduction of herbicide usage as compared to bare ground system.
- Assessing the potential of reducing polyethylene mulch usage with adopting high-residue cover crop systems plus biodegradable mulches in organic production.