RUNOFF AND SOIL EROSION DURING SPRING THAW IN THE NORTHERN US CORN BELT

Authors: Sharratt, Brenton; BENOIT, GEORGE - RETIRED; YOUNG, ROBERT - RETIRED; Wilts, Alan

Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary: Fall tillage is utilized by farmers to speed warming and expedite planting of soils in the northern US Corn Belt. Runoff and erosion, however, frequently occur from these soils during spring thaw. Fall soil management strategies are therefore sought that stabilize the soil and minimize runoff and soil loss in the spring. Runoff and erosion were assessed during spring thaw on soils subject to removal or retention of surface corn residue prior to moldboard plow or chisel plow in the fall. Runoff during a simulated spring rain was smaller from plots with deeper soil thaw, subject to moldboard plow, or greater residue cover. Soil loss was minimized on plots with greater residue cover. In cold regions where fall tillage is utilized to expedite spring planting, farmers can minimize runoff and soil loss by retaining residue on the soil surface prior to fall tillage.

Technical Abstract: Runoff and erosion can be accentuated by partially frozen soil and thereby result in off-site pollution and loss in soil productivity. Runoff and erosion were assessed during spring thaw on a Hattie clay (Udertic Haploboroll) in 1986 and 1990, Barnes loam (Udic Haploboroll) in 1987 and 1988, and a Sverdrup sandy loam (Udic Haploboroll) in 1989 in west central Minnesota. Simulated rain was applied at 0.064 m h-1 to field plots subjec to removal or retention of corn (Zea mays L.) residue prior to moldboard plow or chisel plow in the fall. Soil physical properties were assessed prior to applying rain to each set of tillage and residue treatments on four dates during spring thaw. Total runoff and soil loss was greater from Sverdrup sandy loam than from Hattie clay. Runoff was greatest at the time of initial soil thaw and from plots subject to fall chisel plow and removal of corn residue. Soil loss was minimized on plots with greater residue cover. Runoff was accentuated by a wetter, denser, and smoother soil. Soil loss was accelerated on plots with greater runoff, less residue cover, and smaller random roughness. In cold regions, fall moldboard plow and retention of residue on the soil surface may be desirable for roughing the surface and thereby minimizing runoff and soil loss during spring rains.