1a.Objectives (from AD-416):
Our overall long-term goal for this project is to develop regionally specific information and empower farmers with a new tool that enables adoption of winter cover crops. We will accomplish our goal through the following four objectives: 1. Establish multi-year winter cover crop interseeding demonstration plots at experiment stations and 12 EQIP-eligible farms in the Chesapeake Bay Watershed; 2. Quantify conservation benefits of interseeded cover crops and compare the crop performance and energy use of a 3-way interseeder to standard establishment methods; 3. Create case studies of farmers who have increased whole-farm nutrient use efficiency by using Adapt-N and integrating winter cover crops into their crop rotations; and 4. Develop region-wide cover crops interseeding recommendations and outreach information to producers through on-farm demonstration and innovative content delivery.
1b.Approach (from AD-416):
We will use a series of multi-year, multi-site demonstration trials as one of our primary methods of directly outreaching this technology to farmers. We will focus on interseeding winter cover crops into no-till corn and secondarily soybean and will evaluate the performance of the host corn or soybean crop, the cover crop, and the subsequent corn or soybean crop. At each of the at least 12 farms in three states, we will establish large-scale demonstrations of different cover crop species and mixtures of species interseeded into corn and soybean in years 1 and 2 of the project. Interseeding catch crops such as cereal rye or ryegrass will be compared to legume crops such as crimson clover and hairy vetch and mixtures of grass and legume species. The beneficial effect of growing interseeded grass cover crops prior to soybean and legume cover crops prior to corn will be demonstrated in years 2 and 3 of the project. Demonstrations will also be conducted at research stations where additional monitoring and comparisons will be used to refine management recommendations. We will compare the interseeder to different seeding methods such as post-harvest drill seeding and aerial interseeding. We will also evaluate and demonstrate the effect of different cover crop establishment timings, seeding rates, and mixtures.
While there is overwhelming evidence on the benefits of cover crops to agroecosystems, adoption has been hindered by cover crop establishment methods. Cash crop harvest of most summer annual grain crops occurs late in the fall and can prohibit timely planting of cover crops. Furthermore, aerial seeding of cover crops while the cash crop is growing has been met with limited success due to poor seed-to-soil contact of the cover crop seed. We have custom fabricated cover crop interseeders that sow cover crop seed between cash crop rows using grain drill techniques. The first year of on-station field trials have been installed and we are currently installing on-farm experiments testing this technology. Furthermore, on-station experiments have been initiated to compare aerial seeding and direct drill seeding post-harvest to interseeded approaches.