Effects of nutrient management strategies on dry matter and grain yield of soybean and dry bean cropping systems

Increases in soybean (Glycine max L. Merr.) grain yield can be partially attributed to greater total dry matter (TDM) accumulation, but the relationship between dry matter (DM) accumulation and nutrient uptake across irrigated and non-irrigated conditions remains uncertain. Two multi-year trials investigated soybean dry matter and nutrient accumulation and partitioning, grain yield, and net economic return across multiple seeding rates and fertilizer strategies. The 148,000 seeds ha-1 rate significantly decreased yield in two of four site-years but no differences occurred at the remaining two site-years. Fertilizer strategies did not interact with seeding rate to influence grain yield across all site-years. When contemplating fertilizer application strategies, soil test values should still be the first factor considered. Greater grain yield potential from improved dry bean (Phaseolus vulgaris L.) varieties coupled with potential decreases in soil sulfur (S) supply may have affected the likelihood of a grain yield response to nitrogen (N) and sulfur application. Three multi-year trials were established in Michigan to evaluate nitrogen rate, sulfur rate, and sulfur source on dry bean growth and grain yield. Nitrogen and S application including S source did not improve grain yield or interact with variety to affect grain yield across site-years. Other factors including plant nodulation, biomass, and residual nitrate after harvest were affected by N or S treatments. Nutrient application, especially N, may still be required but in nominal quantities to account for the variable June planting conditions of this shorter-season cropping system. Sulfur applications may be better suited for more N-responsive crops within the dry bean cropping rotation.