Wednesday, November 7, 2007
309-11

Tillage Management and Previous Crop Effects on Soil Physical Properties and Maize Grain Yield.

Walter E. Riedell1, Shannon L. Osborne1, Joseph L. Pikul Jr.1, and Thomas E. Schumacher2. (1) USDA, ARS, North Central Agricultural Research Laboratory, 2923 Medary Avenue, Brookings, SD 57006, (2) Plant Science Department, South Dakota State University, NPB 247A, Brookings, SD 57007

Maize (Zea mays L.) grown in rotation with high residue crops generally has lower grain yield under no-till than under tilled soil management in the northern US maize belt. Hence, the research objectives were to further characterize soil physical properties and maize grain yield under tilled and no-till soil management following soybean (Glycine max L.) or winter wheat (Triticum aestivum L.). The two year field study was conducted on a Barnes sandy clay loam soil (fine-loamy, mixed, superactive, frigid Calcic Hapludoll) in eastern South Dakota USA. Tillage treatments (fall chisel plow prior to winter wheat, fall chisel plow plus spring disk-harrow prior to maize and soybean, or no-till) were started in 2001. Soil temperatures (30 cm depth) in tilled plots after winter wheat were dramatically warmer than no-till plots in June and again in August of the 2004 growing season. In 2003, soil temperatures were very similar across tillage treatments. Soil bulk density (0 to 10 cm depth) and soil penetration resistance (0 to 7 cm depth) were much greater under no-till soil management than under tilled conditions when measured in mid-June (V6 leaf development stage). In the warmer and drier year (2003), maize grain yield under tilled conditions was 8.2 Mg/ha compared with 8.7 Mg/ha under no-till. In the cooler and wetter year (2004), yields were 9.4 Mg/ha under tilled soil management and 7.4 Mg/ha under no-till. The no-till soil management treatment following winter wheat had 27% lower maize grain yield than the tilled treatments and the no-till following soybeans. We conclude that greater bulk density and penetration resistance levels under no-till soil management, along with cool soil conditions that typically occur in the spring in the northern US maize belt, reduced maize yield under no-till soil management in soils with low internal drainage.