Physiological Plant Response Differences among High‐ and Average‐Yield Soybean Areas in Arkansas

Abstract

Core Ideas Crop yield contests provide a unique research opportunity. Planting date is highly related to yield across yield contest sites. An early soybean production system is advantageous for high yields. Increasing soybean [Glycine max (L.) Merr.] yields requires a multi‐pronged approach. Annual state soybean yield contest fields can provide information about yield potentials and plant response differences between high and average‐yield producing areas. The objectives of this study were to i) assess plant physiological property and elemental seed concentration differences between high‐ (HY) and average‐yield (AY) areas and across soybean growth stages and ii) evaluate relationships among plant properties and yield across the seven regions of the “Grow for the Green” soybean yield contest in Arkansas. Seed yields in AY and HY areas averaged 74.4 and 88.3 bu/ac, respectively, in 2015. Harvest index, average seed weight, and seed K concentration differed (p < 0.05) by at least 10% across growth stages and between yield areas. Averaged across growth stage, aboveground dry matter and seed B and C concentrations differed (p < 0.05) by at least 0.7% between yield areas across regions. Averaged across yield area, seed N, P, Ca, Fe, Mn, Zn, Cu, and B concentrations differed (p < 0.05) by at least 2.5% across growth stages. Planting date was most strongly correlated with yield (p < 0.001; r = –0.62), confirming previous research. Encompassing a wide variety of landscapes and management systems, results of this study validate the importance of planting date to soybean yield. Additional factors need to be evaluated to discover stronger relationships with yield to continue closing the soybean yield gap.