Soft red and white winter wheat response to input-intensive management

Abstract

Record grain yields and increased awareness of climate variability have more producers considering intensive (i.e., high-input) wheat (Triticum aestivum L.) management. This study investigated soft winter wheat response to several agronomic inputs across intensive and traditional (i.e., low-input) management systems. A four site-year trial was established at Richville and Lansing, MI during 2015 and 2016 to evaluate the following inputs: increased rates of nitrogen (N) fertilizer, urease inhibitor (UI), nitrification inhibitor (NI), fungicide, plant growth regulator (PGR), and foliar micronutrients. Across four site-years, intensive management did not increase yield compared to traditional management. In addition, traditional management increased average economic net return by $221 ha –1 . At the reduced N rate, Richville 2016 yield decreased 0.94 Mg ha –1 within the intensive system suggesting greater N demand with intensive management. Due to significant stripe rust (Puccinia striiformis f. sp. tritici) occurrence, at 2016 Lansing, yield increased 0.75 Mg ha –1 when fungicide was added to the traditional system. Lansing 2017 yield decreased 0.52 Mg ha –1 when UI was removed from the intensive system, yet decreased 0.51 Mg ha –1 when UI was added to the traditional system. Heavy rainfall, lack of urea hydrolysis, and N rate likely contributed to the inconsistent UI response. The 2016 and 2017 growing seasons produced an overall absence of adverse environmental conditions which influenced negligible input responses. Although yield increases were observed, no single input increased net return. Results suggest intensive management benefits are unlikely at current wheat prices and without the presence of yield-limiting factors.