Crop and Soil Responses to On-Farm Conservation Tillage Practices in the Upper Midwest

In the US upper Midwest, the narrow growing season causes many farmers to presume yield losses when reducing tillage. The purpose of this study was to determine how four production-scale tillage systems affected residue cover, stand populations, crop yields, and soil chemical, biological, and physical properties. Tillage systems (chisel plow, fall strip-till with shanks, spring strip-till with coulters, and shallow vertical till) were continued for 4 yr. Tillage effects within a site were few and mixed (0.17-0.36 Mg ha(-1) difference), whereas site effects were common (0.50-3.00 Mg ha(-1) difference). Among 19 soil properties, only fungal/bacteria ratios differed among strip-till with shanks (0.078) and strip-till with coulters (0.066) at one site. Our results suggest that many farmers' concerns about using conservation tillage practices do not necessarily translate into yield losses when compared to standard chisel plow practices. Economics and the level of erosion control among the tillage practices compared here, rather than yield alone, should guide farmer preferences.