IMPACT OF BANDED POTASSIUM FOR CORN AND SOYBEAN PRODUCTION IN A RIDGE-TILL PLANTING SYSTEM

Potassium (K) deficiency symptoms in corn (Zea mays L.) grown in the r idge-till planting system were a major concern for producers who used this planting system. The purpose of this study was to develop managem ent practices for use of K fertilizer in the ridge-till planting syste m. The study was conducted on a farm in southwestern Minnesota where t he ridge-till planting system had been used for several years. The fir st year was devoted to an evaluation of rate of K (0, 37, 74, and 148 kg K/ha) applied in a band in the center of the ridge on growth and yi eld of three corn hybrids. Frequency of K application was evaluated fo r soybean [Glycine max L. (Merril)] production in the second year and corn in the third year of the study. The response tb K use and the K r ate x hybrid interaction were significant. Residual effects of banded K were evident with both corn and soybeans if rates of 74 kg K/ha or h igher were used. The data collected show that use of banded K is impor tant for corn and soybean production for the ridge-till planting syste m. This is true even though K soil test values may be in a range that is considered to be high or very high.