Potential of Interseeding Cover Crops in Corn While Sidedressing and Applying Postemergent Herbicides.

Interseeding cover crops in no-till corn and soybean fields can be challenging.  Broadcasting the seed late in the season is one option, but the results are inconsistent.  Cultivating early in the season and broadcasting seed has been another option, but is difficult in no-till, high residue fields.  Both of these approaches involve a separate trip across the field, increasing the cost of cover crop establishment. To address this issue we have developed a machine to interseed a cover crop at the V6-V8 growth stage of corn in no-till fields that can apply N fertilizer and a postemergent directed herbicide at the same time.  This approach has several advantages: multiple trips across the field can be combined, reducing the cost of cover crop seeding, good seed to soil contact achieved with the potential of reducing cover crop seeding rates, and the N and herbicide applications can be directed to maximize efficiency. The system is particularly well adapted where the season is too short to establish cover crops following harvest, where grazing a cover crop in the corn field is desired, or where the corn stover may be removed and a fall cover crop with good growth is desirable.  The system has been tested for two years and has resulted in successful cover crop establishment in approximatley 80% of our trials.  Cooperating producers have used the cover crops for forage and the system has potential to provide significant economic returns and soil conservation and soil qulaity improvement in corn based cropping systems.  We anticipate that improved corn yields in succeeding years with less nitrogen inputs can contribute to large economic benefits in the years following the initial interseeding.