Agronomic Practices for Reducing Wheat Yield Gaps: A Quantitative Appraisal of Progressive Producers

Abstract

There is limited information on agronomic practices affecting wheat ( Triticum aestivum L.) yield in intensively managed dryland systems despite the opportunity to narrow the existing yield gap ( Y G ). We used a unique database of 100 intensively managed field‐years entered in the Kansas Wheat Yield Contest during the 2010 to 2017 harvest seasons to (i) quantify the Y G , (ii) describe wheat management, and (iii) identify management opportunities and weather patterns associated with yield. We simulated wheat water‐limited yield ( Y w ) using Simple Simulation Modeling–Wheat (SSM‐Wheat) model for each field‐year to estimate Y G as the difference between Y w and actual yield ( Y a ) and used 11 statistical approaches to test the association of management practices and weather variables with Y a . Wheat Y a averaged 5.5 Mg ha −1 , and simulated Y w averaged 6.4 Mg ha −1 , resulting in a Y G of 0.9 Mg ha −1 (15% of Y w ). High‐yielding fields had lower maximum and minimum temperatures and greater cumulative solar radiation and precipitation during grain fill. Varieties susceptible to fungal diseases responded to foliar fungicide (0.8–1.4 Mg ha −1 ), whereas resistant varieties did not. Seeding rate was negatively associated with Y a , as yield quantile 0.99 was 7.5 Mg ha −1 and decreased by 2.7 Mg ha −1 for every 100‐seed m −2 increase in seeding rate above 305 seeds m −2 . In‐furrow P fertilizer, previous crop, tillage practice, and N timing were also associated with Y a . We conclude that fields entered in yield contests have closed the exploitable Y G , and there are opportunities to improve Y a through improved management in regions with stagnant wheat yield.