Cover Crop and Tillage Affects On Soil Organic Carbon.

The primary objective of this research was to determine the effects of cover crops and tillage treatments on soil organic carbon (SOC) content of an eroded soil. No-till (NT), chisel plow (CP) and moldboard plow (MP)) plots were split in 2001 with a cover crops applied to half. By 2007, the tillage zone, subsoil, and rooting zone of all treatments had higher organic C on a volume basis for the cover crop treatments than for the same tillage treatment without a cover crop. However, using the baseline 2000 soil organic C contents only the NT with cover crops maintained the soil organic C levels in the topsoil and subsoil. Any soil organic C gain for the NT from cover crops was off set by an equal loss of soil organic C from planting disturbance, nitrogen injection disturbance in corn years, mineralization and soil loss from water erosion.  With the CP and MP plots with cover crops were compared to the baseline 2000 soil organic C contents the cover crops did not maintain organic C levels in the tillage zone. No soil organic C sequestration (net increase) occurred for any of the tillage treatments with cover crops over time when compared with baseline levels of each tillage treatment prior to application of the cover crops and tillage over time.