Legacy Effects of Three Management Practices on Corn, Soybean, and Wheat Yield

Core Ideas Effect of management on subsequent crop yield variability is an important concern. There was no evidence of legacy fungicide effect on corn, soybean, and wheat yield. Corn silage and wheat after soybean exhibited a quadratic response to residual N. The effect of management on subsequent crop yield and quality variability is an important concern. However, there are a lack of studies that examine legacy effects of important management practices on corn ( Zea mays L.), soybean [ Glycine max (L.) Merr.], and wheat grain yield ( Triticum aestivum L.). The objective of this study was to examine the legacy effect of N fertilizer and foliar fungicide, on corn, soybean, and wheat grown in rotation in no‐till (NT) and the use of nematicide seed treatment under conventional and NT systems on corn, and soybean grown in rotation. Data were collected in 2016 in Wisconsin from two long‐term crop rotation experiments conducted during 2013 to 2015, that had continuous management treatments applied (N, foliar fungicide, tillage, and nematicide seed treatment). The results showed no evidence of residual fungicide effect on yield of any of the three crops or on wheat test weight. Within the 14 crop rotations, corn harvested for silage (LCWS) and wheat after soybean (CSW) exhibited a significant quadratic response to residual N. For corn‐LCWS, 3 yr of N under‐ and overfertilization reduced subsequent yield, whereas above‐optimum N rates resulted in wheat‐CSW yield reductions in the following year. A nematicide seed treatment legacy effect was observed on corn grown under NT where yields were similar or lower than the untreated control. Overall data suggest that legacy effects after 3 yr of uniform practices are management specific. Nevertheless, examination of such effects in long‐term experiments is imperative.