Soil Potassium Effects on Cotton Growth, Yield, and Quality in the Texas High Plains.

Cotton yield potential has increased, which should increase the plant’s potassium (K) requirement. Soil K levels in west Texas are often reported to be greater than the critical level of soil K (125 ppm). Research has demonstrated a positive response to liquid K fertilizer on cotton yield, however these results are not consistently observed. In this experiment lint yield, reproductive development, and fiber quality was investigated at Lamesa and New Deal, TX. The main objectives were to: 1) evaluate application methods and rates of K fertilizer that may affect cotton yield, quality, and growth, 2) determine the interactive effect of specific node zones and K fertilization on plant development; and, 3) re-evaluate soil K concentrations in order to improve soil recommendations to maximize yield in the Texas High Plains. In 2016 K was applied using two different application methods, broadcast (0-0-60) and knife injected (0-0-15) at five rates (0, 45, 90, 135, and 180 kg K ha^-1). Two irrigation levels of low (11.4cm) and high (17cm) were applied throughout the growing season. Box mapping was conducted on 3m per row plots for specific node zone determination of K. Results indicate that high irrigation increased boll count, lint yield, and leaf tissue K. Potassium application rate had no significant effect on lint yield. Additional research is needed to determine which nodes zones were affected by K fertilizer and if the node zones had a significant impact on cotton growth, yield, and quality.