Investigating avenues of increasing nutrient use efficiency in soybeans and winter wheat in Oklahoma

Abstract

A large part of the land-grant mission is to increase production and sustainability in growing crops to feed and clothe our world. One aspect that allows us to get closer to obtaining our goal is to increase our nutrient use efficiency (NUE). Increasing our NUE allows producers to reduce waste and increase profits. This has led to the development of a strategy to increase NUE, known as the 4R's of Nutrient Stewardship Concept (Johnston & Bruulsema, 2014). The 4R's stand for applying the right source of nutrients, at the right rate, at the right time, in the right place. Many research studies in the past two decades have utilized that concept to influence nutrient recommendations. This dissertation aims to assess Oklahoma State University's (OSU) nutrient recommendations for optimizing yield, as well as utilizing two of the 4R's (right rate, right time) to refine nutrient recommendations. We conclude that while on average, OSU's nutrient recommendations perform well optimizing yields, there are avenues for refinement to increase NUE in soybeans and winter wheat in Oklahoma.