Submitted to: Management of Landscapes Disturbed by Channel Incision Stabilization Rehabi
Publication Type: Proceedings
Publication Acceptance Date: March 7, 1997
Publication Date: N/A
Interpretive Summary: Research was conducted from 1988 to 1996 in north Mississippi to see if crops could be successfully grown on sloping fields without causing excessive erosion. The land studied is considered "highly erodible," meaning it is susceptible to high soil erosion rates when farmed with conventional tillage. This work was done as part of a larger research within the Yazoo River Basin effort called the Demonstration Erosion Control project (DEC). Runoff and soil erosion were monitored on three soybean fields ranging from 5 to 8 acres in size and with slopes averaging 4%. For the first two years, the field were treated equally. After that, two of the fields were planted þno-tillþ (without any tillage) and the third was farmed with conventional tillage. Grassed strips were used to help control erosion where runoff concentrated in low areas of each field. Results showed that no-till management reduced erosion from 90 to 98%, reduced runoff water amounts about 10%, and produced crop yields equal to or greater than those of conventional tillage. Even with grass strips, erosion rates were unacceptably high with conventional tillage. These studies found that no-till crop management can control erosion on typical DEC fields without sacrificing crop productivity. When used with grassed waterways and grass hedges to control concentrated flow erosion, no-till can enable sustainable crop production on these fields.
Technical Abstract: Research was conducted at the A. E. Nelson Farm to determine the conservation and economic impacts of alternative soybean cropping systems on field-sized areas within DEC watersheds. Runoff and sediment yield were monitored on three watersheds (WS), ranging from 5 to 8 acres in size with slopes averaging 4% and ranging from 1 to 8%, that were planted with soybean. No-tillage management greatly reduced sediment yield compared to conventional tillage and reduced runoff about 10%. Annual sediment yield never exceeded 1 t/a with no-tillage, but varied from 1.3 to 14.5 t/a/yr during the same period with conventional tillage. Buffer strips and waterways provided inadequate erosion control in a conventional tillage watershed and deteriorated in areas with heavy sediment loading. No-tillage alone was not adequate to control growth of concentrated flow headcuts once they were initiated. Sediment yields were highest (up to 34 t/a/yr) after concentrated flow areas were disturbed by earthwork to fill and stabilize gully headcuts and establish waterways. These studies demonstrated that no-till crop management is effective in controlling sediment yield from sheet and rill erosion on typical DEC fields and that crop yields can be equal to or greater than with conventional tillage management. When used together, waterways, grass hedges, and no-till can provide comprehensive protection and sustainable crop production on field areas of the size and type studied.