Database Research SummariesAgronomic and Irrigation Efficiency Impacts of Conservation Tillage and Cover Crops in Soybean Production: Three-Year Results
The focus of this research is to determine the impacts of implementing cost efficient soil health production systems throughout the Midsouth.
- Determine the effect of conservation tillage (conventional tillage, reduced tillage, zone tillage) and cover crops [cereal rye, tillage radish, no cover crop] with conservation tillage on soybean grain yield, net return above specified costs, irrigation application efficiency, and agrochemical transport.
- Soybean grain yield was not influenced by conservation tillage or a cereal rye cover crop during the year one transition period. When averaged across years two and three, conservation practices did alter soybean grain yield. Conventional tillage/no cover was no different than MT/SS or MT/RC, but was greater than ZT/TR, MT/NC, ZT/NC, and MT/TR. Minimum tillage/sub-soiling was greater than only MT/TR and no other treatments were different from one another. These results agree with similar studies which reported no differences in soybean grain yield following a cereal rye cover crop and reductions in a no-tillage system.
- Net returns above specified costs were not influenced by conservation tillage or a cereal rye cover crop during the year one transition period. However, net returns were affected by treatments when averaged across years two and three. Net returns above specified costs for MT/SS, CT/NC, and ZT/NC were greater than those for MT/RC and MT/TR, but were no different from those for ZT/TR, and MT/NC. Similarly, ZT/TR and MT/NC were not different from one another, but were greater than those for MT/TR, while MT/RC and MT/TR net returns were not different.
- Evaluated production systems that promote soil health improved irrigation application efficiency, extended furrow advance times, and reduced runoff volume. Increasing furrow advance times allows irrigation water to remain in the furrow longer, potentially increasing infiltration and decreasing runoff volumes. Zone tillage/no cover reduced runoff volumes by at least 60% relative to MT and CT; however, cumulative runoff for MT/RC was only different from MT. Irrigation application efficiency for MT/RC and ZT/NC was at least 13% greater than for CT and MT.
- Farmers now know that soil health BMP’s that include CC or conservation tillage can be applied in the Midsouth without affecting soybean grain yield.
For more information about this research project, please visit the National Soybean Checkoff Research Database.
Funded in part by the soybean checkoff.