Effect of Strip-Till Timing, Fertilizer Placement, and Row Spacing on Soybean Seed Yield

Abstract

Core Ideas A reduction in penetration resistance was observed in the rooting zone of fall and spring strip-till rows compared with no-till rows. Spring strip-till reduced penetration resistance at more depths than fall strip-till. There was no yield response of strip-till compared with no-till in the small-plot study. There was no difference in plant population or yield between strip-till or no-till in the on-farm study. The perceived yield deficit normally associated with 30-in row spacing was reduced with the use of strip-till. Alleviation of cold, wet, compacted soil is a major concern for Wisconsin soybean [Glycine max (L.) Merr.] growers because of the narrow harvest and planting windows in spring and fall. Strip-till, which combines benefits of intensive tillage in crop rows and no-till between crop rows, has emerged as a viable conservation tillage option to alleviate these issues while maintaining soil structure and health. Though strip-till's yield response in corn (Zea mays L.) is well documented, soybean's yield response has been studied less. This study aims to: (i) quantify the effect of no-till and strip-till timing, crop row spacing, and fertilizer placement on soybean plant population, canopy coverage, and seed yield; (ii) evaluate no-till and strip-till timing and/or crop row spacing on soil temperature and penetration resistance; and (iii) determine the best management recommendations for strip-till use in Wisconsin soybean production systems. A small-plot experiment was conducted in Arlington, WI, during the 2016, 2017, and 2018 growing seasons and an on-farm experiment was conducted in Sharon, WI, during the 2016 and 2017 growing seasons. In the small-plot trial, 15-inch spring strip-till (66.5 bu acre-1) yielded 6.7% more than 15-inch fall strip-till (62.0 bu acre-1). There was no difference in yield between the 15-inch and 30-inch row spacings across all tillage treatments. Plant population in the small-plot trial was 17,000 plants acre-1 (15.5%) greater at the 30-inch row spacing than at the 15-inch row spacing. In the on-farm trial, no differences were observed among treatment combinations. Overall, results suggested that there were no differences in yield when comparing strip-till and no-till for soybean production.