Boron for soybeans grown in Georgia

The need for boron (B) applications on soybeans (Glycine max L. Merr cv. Hutton) grown on soils low in extractable B is debatable. It is often thought that soybeans grown on these soils will not respond to B fertilizers unless environmental conditions are favorable for relatively high production levels. The purpose of this study was to evaluate the effect of soil‐applied B (0.28 to 2.24 kg/ha) on yield and nutrient uptake of soybeans grown on soils with low hot‐water‐soluble B levels (<0.20 ppm) and under several environmental conditions. Four locations and a total of nine crop years were used to evaluate B responses under various environmental conditions. Soil, leaf, and grain B levels increased (quadratic response) with increasing rates of applied B, but responses varied among years and locations. Soil B levels were not necessarily a good indication of the B supplying capability of the soil. The highest grain B levels did not necessarily come from plants which contained the highest leaf B levels. In three of the nine years, positive yield responses to applied B (up to 1.12 kg/ha) were recorded but these responses were low and not always related to years in which environmental conditions favored high yield levels. A negative response occurred one year when compared to the O B rate and in a second year when compared to the 1.12 kg/ha B rate. Based on currently available data, B applications for soybeans may be questionable when grown on soils similar to those reported here.