Managing Global Resources for a Secure Future

No-till management is one of our management tools with the most potential to preserve topsoil and its organic matter, securing future food production. Cover crops are another tool with substantial potential to protect topsoil. Our objective was to evaluate the effect of tillage and cover crop management on soil organic C. Two experiments (corn-corn and corn-soybean rotations) were initiated in 2011 and terminated in 2015. Treatments were factorial combinations of tillage (no-tillage vs chisel-disk) and cover crop (no cover vs rye). Soil C was measured to 60-cm depth in 32 plots in spring 2011 and in 128 plots in fall 2015. After 5 years, tillage had reduced soil C by 0.03% C to 60 cm relative to no-till in the corn-soybean rotation. This is likely due to erosion that occurred in tilled plots in a 13-cm rainfall in early April 2014, resulting in deep gullies down the chisel plow tracks. Soil C was not affected by cover crop, or by tillage in the continuous corn rotation. A rye cover crop did not affect soil organic C, but did help to maintain soil organic N in both rotations relative to no cover crop.