Agronomic Maximization of Soybean Yield and Quality: Row Spacing x Management Interaction.

Yield-enhancing products in soybeans have become increasingly popular in recent years in response to higher commodity prices.  However, little research has been done looking at the combinations of these products with different production practices.  Narrow row spacing along with these yield-enhancing products may be an effective way of maximizing soybean yield. The objective of this study was to evaluate the interaction of aggressive and standard soybean management practices with different row spacings.  Three row spacings: 25-cm, 51-cm, and 76-cm and four management practices: untreated, fungicide and insecticide seed treatment plus foliar fungicide, “SOYA Complete” (combination of several seed treatments, nitrogen, and numerous foliar products), and “SOYA Complete” minus foliar fungicide were evaluated at five locations (three in Kansas and two in Minnesota) in 2012 and 2013.  In Kansas, no significant differences in yield were found between the three row spacings across all locations.  The fungicide and insecticide seed treatment plus foliar fungicide yielded significantly more at one location.  Stand counts taken at V2/V3 and R8 improved with increasing row spacing at one location.  The untreated and fungicide and insecticide seed treatments plus foliar fungicide managements had consistently higher stand counts at two locations. With 2012 precipitation being 34.9cm below the 30-year average and above normal average high temperatures during the growing season, some main effects may have been hidden.  Response to aggressive soybean management practices did not depend on row spacing.