Submitted to: Journal of Soil and Water Conservation
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/15/2004
Publication Date: 12/1/2004
Citation: Buman, R.A., Alessi, B.A., Hatfield, J.L., Karlen, D.L. 2004. Profit, yield, and soil quality effects of tillage in corn / soybean rotations. Journal of Soil and Water Conservation. 59:260-270. Interpretive Summary: Farmers seek information on improved management practices for corn and soybean production; however, they are often concerned because the available information is collected at limited number of sites and not representative of their soils or climates. A study was undertaken to compare tillage systems on corn and soybean production across the central United States. These experiments were conducted on soils typical of the region and included a number of different tillage practices that ranged from intensive tillage to no-tillage production systems. There was no difference in the crop yields among the different tillage systems; however, the profit was consistently greater in the reduced tillage systems. This information will help producers gain confidence in the adoption of reduced tillage systems that decrease erosion, improve environmental quality, and increase profitability of corn and soybean production.
Technical Abstract: Adoption of conservation tillage for corn (Zea mays L.) and soybean (Glycine max L.) rotations, adoption of no-tillage and strip tillage has stagnated over the past several years despite the evidence of the benefits from erosion control, soil health, and associated natural resources derived from conservation tillage. The Monsanto Centers of Excellence (COEs) were established to evaluate the potential benefits of conservation tillage across a range of soils and climates. Our objective is to summarize the results from field-scale studies conducted at 13 COE sites in nine states from 1998 through 2002. Strip-tillage, no-tillage, and conventional corn production, as well as narrow- and wide-row, no-tillage and conventional tillage soybean production were evaluated in this study. Nine of the 13 sites also included a "fast start" corn treatment that included conventional fall tillage followed by only a spring herbicide burndown if needed. Neither soil bulk density nor crop emergence showed any significant differences for either crop throughout the 5-year study. Earthworm populations were higher with no-tillage than conventional tillage. Soil temperature at the 5-cm depth was similar for strip- and conventional-tillage, with both being higher than no-tillage. Yield differences within years were not significant for either crop, but profit for no-tillage and strip-tillage corn was the highest in 4 of 5 years. The 5-year average profit for soybean was also highest for the no-tillage, narrow-row system. Rotating between those tillage/crop systems resulted in $130 to $140 ha-1 more profit than the other practices. We conclude that farmers, crop consultants, and others should carefully consider overall profit rather than just crop yield when evaluating alternative tillage practices.