Influence of Input-intensive Management on Soft Winter Wheat and Soybean Grain Yield and Profitability

摘要

Increasing grain yields, climatic variability, and commercial marketing has prompted many wheat (Triticum aestivum L.) and soybean [Glycine max (L.) Merr.] producers to adopt input-intensive management systems for maximum yield. Field studies were conducted in Lansing and Richville, MI from 2015 -- 2017 investigating soft winter wheat and soybean grain yield and economic net return in response to commonly marketed agronomic inputs applied to both intensive (i.e., high-input) and traditional (i.e., low-input) management systems. Wheat inputs included greater rates of nitrogen (N) fertilizer, urease inhibitor (UI), nitrification inhibitor (NI), plant growth regulator (PGR), foliar micronutrients, and fungicide. Soybean inputs included poultry litter (PL), potassium thiosulfate (KTS), foliar micronutrients, and fungicide. Wheat yield decreased 0.94 Mg ha-1 when N rate was reduced within the intensive system and increased 0.75 Mg ha-1 when fungicide was added to the traditional system in 2016. Urease inhibitor removal from the 2017 intensive system decreased wheat yield 0.52 Mg ha-1 while UI addition to the traditional system decreased wheat yield 0.51 Mg ha-1. Although wheat yield occasionally increased, no single input increased economic net return. Across all site-years, no single input positively affected soybean grain yield or profitability. In the current study, intensive management systems significantly decreased producer economic net return in 6 of 7 site-years. Results suggest producers should expect few benefits from input-intensive management systems without the presence of yield-limiting factors.