The University of Nebraska recently published a massive report detailing all of the results of their 2019 on-farm research. Of course, cover crops were included in those research findings. There were several interesting tidbits from that report:
- Cover crops kept the soil warmer than soil without covers. One study on irrigated soybeans planted following a cover crop mix measured soil temperatures in October. The fine sandy and silt loam soil with rye, forage collards, turnips, rapeseed and kale were warmer than soil without covers. Keeping that armor on the soil is critical to retaining heat — and allowing covers to continue growing and providing their benefits to the soil.
- Irrigated soybeans planted after a cereal rye yielded 1.2 bushels per acre more. When it comes to higher yields, every bushel adds up.
- In one study on how the seeding rate of rye as a cover crop affects irrigated corn, the results showed that an increased rye seeding rate increased cover crop total dry biomass. There were no differences in corn grain moisture or test rate, and stand counts varied.
- A study comparing monoculture rye as a cover crop to a multi-species cover crop of rye, red clover, rapeseed and hairy vetch found the monoculture rye yielded higher than the multispecies cover crop mix. The monoculture rye also had a higher net return than the cover crop cocktail.
- One study compared 3 different treatments, including irrigated soybeans/post-harvest interseeded cover crops (cowpeas, soybeans, crimson clover, sunnhemp, hairy vetch, buckwheat, chicory, flax, rapeseed, cereal rye and spring oats) and no covers. In the second year of the study, there were differences detected in soil respiration and soil pores. Soil respiration was reduced and the no cover and interseeded cover crops had lower soil pore scores.
- A 3-year study was done to determine the effects of grazing cover crops on a no-till crop rotation of wheat, corn and soybeans planted cover crops after the wheat, such as winter peas, spring triticale, oats, collards and purple top turnip. Cattle were grazed on the covers. Post-grazing, 2,177 pounds/acre of biomass were still present in the field. The cover crops didn’t result in lower beginning moisture, which could limit yield potential for the field. After the corn rotation, cattle were grazed on the field. Grain moisture was significantly higher for the field with the grazed corn stalks. Grazing the cover crop caused no changes 2-4 inches deep in the soil.