Soybean Yield Response to Maximum Yield Management.

Mr. Kip Cullers reported the highest recorded soybean [Glycine max (L.) Merr.] yield of 10,791 kg ha^-1 for the 2010 Missouri Soybean Association yield contest. A maximum yield environment was created in small plot research at Fayetteville, AR using many of the same management practices as Mr. Cullers. These practices included soil testing and amending nutrients to high levels, application of 17.1 (2011) to 21.8 (2012) Mg ha^-1 poultry litter, deep tillage, early planting (9 May in 2011 and 11 Apr. in 2012), overhead irrigation at a 25 mm deficient, N, K and S fertilization via the irrigation system, preventative fungicide applications, and strict pest management. Twelve or fourteen indeterminate cultivars of relative maturity (RM) 4.4 to 5.5 were evaluated for crop and seed-growth characteristics and yield. In addition, two 4.9 RM cultivars were selected to evaluate the yield response to even intra-row spacing or plant height at emergence, herbicide burn at the V4 growth stage, inoculant and plant health seed treatments, and prevented lodging. In 2011, yield among the 14 cultivars ranged from 5464 to 3901 kg ha^-1 and yield for the management treatments with two cultivars ranged from 6082 to 4916 kg ha^-1. Abnormally high temperatures from June to August likely suppressed yield. Antagonism may exist among seed treatments as Bio-Forge^® alone and the untreated treatments had 15 and 7% greater yield, respectively, than the control with all combined seed treatments. Minor herbicide burn increased yield 4% compared with the control, while severe herbicide burn increased yield 21%, possibly due to compensatory growth. These results highlight a few unconventional practices which may increase yield in other production environments. This research also confirms that Mr. Cullers’ management practices are capable of producing high soybean yields.