Agronomic Management Practices to Maximize Yield of Ohio Soybean.

Soybean [Glycine max (L.) Merr] is one of the world’s most important crops, supplying approximately half of the global demand for vegetable oil and protein. In 2013, Ohio had a record high soybean yield of 3.29 Mg ha^-1_. Further yield increases are critical to meet the food and bio-based product demand. The objective of the study was to evaluate the effects of commonly used inputs on soybean grain yield in high-input and traditional (reduced input) production systems. The inputs evaluated include Rhizobia inoculant, gypsum, pyraclostrobin fungicide, lambda-cyhalothrin insecticide, and manganese foliar fertilizer. A trial was performed in nine locations throughout Ohio in 2013 and 2014. Rhizobia inoculant was applied to the seed before planting, gypsum was applied at VC (unrolled unifoliate leaves), and the fungicide, insecticide, and Mn foliar fertilizer were applied at R3 (initial pod development). Measurements collected throughout the season include visual disease ratings, visual insect defoliation damage ratings, Mn tissue concentrations, and leaf greenness with a SPAD meter. Plants were harvested at maturity and yield was adjusted to 13% moisture. Statistical analysis was performed using SAS software, and ANOVA was calculated. Treatment means were separated using single degree of freedom contrasts. Preliminary results from 2013 indicate omission of pyraclostrobin from a high input production system reduced yield in 3 out of 9 locations by 0.21 to 0.79 Mg ha^-1, but addition to a traditional system does not increase yield. During 2013, with established corn/soybean rotations, no sulfur or manganese deficiencies, and limited insect pressure, there was no beneficial effect of inoculant, gypsum, insecticide, and manganese foliar fertilizer on grain yield. Regularly scouting is useful to identify inputs that will increase soybean yield.