Effect of Paraplowing on Crop Yields with No-Till Planting

Abstract

No-till acreage has expanded rapidly in the past 5 yr in the U.S. Corn Belt. Yield potential often improves with no-till planting on well drained and low organic matter (OM) soils, but no-till yields are sometimes at a disadvantage on dark, poorly drained soils. Restricted plant rooting due to increased soil density is sometimes reported with no-till planting. Deep tillage with a Paraplow 1 (Tye Co., PO Box 218, Lockney, TX 79241), leaving most surface residue undisturbed, was evaluated on three soils in Indiana for continuous corn (Zea mays L.). Annual paraplowing and biennial paraplowing were used with no-till and moldboard plow systems. On dark, poorly drained silty clay loam, annual paraplowing improved stand, growth, and yield, compared with traditional no-till planting. On a silt loam soil with 2% OM, response to paraplowing for no-till was variable and on a 1% OM soil, paraplowing did not improve no-till yield. Carryover effect from biennial paraplowing for no-till planting was not consistent, even on silty clay loam. Paraplowing did not improve plowed yields on any of the three soils. Paratilling was also used on four rows of each 12-row plot in the 15th year of a long-term tillage study on silty clay loam soiL Plow, chisel, ridge, and no-till systems were used in continuous corn, corn after soybean [Glycine max (L.) Merr.], soybean after corn, and continuous soybean. In no-till continuous corn, there was a positive response to paratilling, but yield for no-till plus paratilling was significantly lower than plowed yield. With conditions similar to conditions in these studies, deep soil loosening is likely to improve no-till continuous corn yield on dark poorly drained soil, but is not likely to improve yield on well drained or low OM soils where traditional no-till is well adapted.