Cover Crop Options for Prevented Plant Acres
June 14, 2019
Conversations with farmers, crop consultants and crop insurance providers lead us to the conclusion that prevented plant will be claimed on significant acreage in 2019, especially since the full coverage crop insurance deadline for corn has passed. While this situation is difficult, especially in the current farm economy, it’s important to plan ahead and use the situation to maintain/ improve soil health by planting cover crops on this acreage.
In addition to protecting soil, covers can help to manage problematic weeds, add to soil carbon, enhance soil health through the interaction of their growing roots with the soil biological community and possibly provide supplemental livestock feed. They also prevent yield reduction in crops the following year due to “fallow syndrome”.
In response to widespread prevented plant acreage in 2013, the Natural Resources Conservation Service published a bulletin entitled “Cover Crops to Improve Soil in Prevented Planting Fields” available at https://www.nrcs.usda.gov/Internet/FSE_DOCUMENTS/stelprdb1142714.pdf This publication offers many helpful recommendations for dealing with the current situation. Given the time of year, reported shortages of seed, especially oats and lack of experience planting winter rye this time of year we offer the following recommendation: plant warm-season species.
Sorghum-sudan, alone or in a mix will provide rapid soil cover, greatest dry matter yields, will be competitive with problematic weeds and properly managed, provide cover throughout the season. It will also maximize nitrogen retention in situations where fertilizer N was applied. Unlike cool season species, it will grow rapidly under warm conditions and it’s also tolerant of dry conditions. In our multi-year trials which included dry summers, a July 1 planting date averaged 7.62 tons of dry matter per acre by the first frost. While more expensive, using a mix offers additional potential benefits including N fixation and differing root architectures to improve soil physical properties. In our 2018 on-farm trials, a mix containing approximately one-third sorghum-sudan produced 84% ground cover by 30 days after planting.
The other reason to consider sorghum-sudan is to replace carbon which is ordinarily provided by corn stover. At this point most prevented planting claims are likely on corn acres.
Sorghum-sudan planted before July 15th has the potential to produce viable seed so will require clipping. Our experience is that stalk choppers work well for this purpose. It can also be harvested for forage if you take the partial prevented plant indemnity. The combination of forage income and partial payment may exceed the full payment.
Choice of cover crop will change as the season progresses. Consult the NRCS publication for options. Additional information will be available soon on the UW Nutrient and Pest Management Program website: https://ipcm.wisc.edu/downloads/