Performing Department
(N/A)
Non Technical Summary
Increasing organic grain and forage production is crucial to meet the escalating demand for these products for human and animal consumption. However, organic systems typically experience multiple production challenges that lower yields compared to non-organic counterparts, with a larger yield gap for field grain crops. Although acreage under organic field grain crops is increasing, domestic production remains insufficient to meet consumer demand. Sustainable intensification of existing organic production systems is thus needed. Double cropping, harvesting two crops from the same land in one year, can help decrease the gap between market demand and domestic production. The long growing season of the southeastern U.S. provides favorable conditions for double cropping, which is already practiced by conventional producers and many transitioning producers in this region. Stakeholders have expressed interest in implementing this yield-boosting strategy in organic systems. Using a system approach, we will evaluate multi-tactic organic double-crop strategies (growing a winter grain/forage crop before soybean) relative to full-season soybeans in Tennessee and Florida, which have distinct climate and soil types. We will test several rotational options as well as residue and weed management techniques to optimize production (grain and forage yield and quality), weed pressure, nematode occurrence (specifically in Florida), profitability, nutrient cycling, soil carbon accumulation, and soil health. The research outcomes will be shared with stakeholders through comprehensive extension and education programs at both locations.
Animal Health Component
65%
Research Effort Categories
Basic
25%
Applied
65%
Developmental
10%
Goals / Objectives
Objective 11a: Compare the effect of different double-crop systems relative to single-crop systems on grain and forage yield and nutrient uptake, forage nutritive value, and weed pressure.1b: Within each system, compare the effect of different residue and weed management methods on grain and forage yield and nutrient uptake, forage nutritive value, and weed pressure.Objective 22a: Quantify the impact of different double-crop systems relative to single-crop systems on soil physical, chemical, and biological health metrics with a special emphasis on nutrient cycling, soil organic carbon dynamics, and nematode communities.2b: Within each system, quantify the impact of different residue and weed management methods on soil physical, chemical, and biological health metrics with a special emphasis on nutrient cycling, soil organic carbon dynamics, and nematode communities.Objective 33a: Conduct a comparative economic analysis to compare profitability among full-season and DC systems and between grain and forage-based DC systems3b: Assess the production, marketing, and financial risk management tools available to organic crop producers.Objective 4Integrate the knowledge and experience generated from intensified row crop systems into Extension and education programs that aim to improve producers' awareness and adoption of organic double-cropping in row crop systems.
Project Methods
We will conduct a 3-year field experiment on certified organic lands at two locations: Knoxville, TN and Citra, FL. We will test slightly different crop rotation treatments in each location to align with the differences in biophysical conditions (climate and soils), growing period, stakeholder preference, and marketing opportunities. There will be five rotation treatments in each location, which will include two full-season soybean and three DC soybean systems. Each treatment will have a summer crop rotation of single/DC soybean-corn-single/DC soybean. The winter crop choice preceding single/DC soybean includes rye and wheat, and barley as cover crops, wheat and barley for grain, and wheat and barley for forage, depending on the study location and rotational treatments. Each rotational treatment plot will be split into two subplot treatments to test two different residue and weed management goals: Subplot 1 for maximizing production by managing weeds with aggressive tillage and Subplot 2 for enhancing SOC accrual and soil health by reducing physical soil disturbance. Cover crops before corn was also varied to provide more N in Subplot 1 and more C inputs in Subplot 2. We will evaluate changes in grain yield and nutrient uptake between full-season and double crop soybean systems as well as between two residue and weed management strategies within each system. We will also quantify the forage yield and nutritive value, and weed pressure from treatments in which forage production was incorporated. Soil samples will be collected from both sites on a biannual basis for three years from 0-10 and 10-30 cm depths. The samples will be analyzed for nutrient availability, soil organic carbon accumulation, nematode population, and overall soil health. We will collect all the necessary data to conduct an economic evaluation of the tested practices in years 3 and 4. A comprehensive Extension and education program will be implemented to disseminate the research experiences and knowledge to a wide range of audiences.