Long-Term Effects of Cover Crops on Crop Yields, Soil Organic Carbon Stocks and Sequestration

Abstract

A 12-year cover\rcrops study on the effects on SOC sequestration, storage, retention and loss\rand corn and soybean yields was conducted in southern Illinois. The use of\rcover crops for the maintenance and restoration of soil organic carbon (SOC)\rand soil productivity of previously eroded soils were evaluated. No-till (NT),\rchisel plow (CP), and moldboard plow (MP) treatment plots with and without\rcover crops were established in 2001. The plot area was on sloping with a\rmoderately well drained, eroded soil. The average annual corn and soybean\ryields were statistically the same for NT, CP, and MP systems with and without\rcover crops. By 2012, the cover crop treatments had more SOC stock than that without\rcover crops for the same soil layer and tillage treatment. The NT, CP, and MP\rtreatments all sequestered SOC with cover crops. A pre-treatment SOC stock\rbaseline for rooting zone was used to validate the finding that cover crops\rsequestered SOC in the topsoil, subsoil and root zone of the NT, CP and MP\rtreatments during the 12-year study. Additional sequestered SOC was lost as a\rresult of being transported off of the plots and retained in lower slopes,\rtransported to the stream or released to atmosphere.