Potassium Fertilization of Irrigated Cotton on Sandy Soils

Jessica G. Davis-Carter, Shelby H. Baker, and Steven C. Hodges


 
ABSTRACT

The objectives of this study were 1) to determine whether Georgia fertilizer recommendations for K in cotton need to be changed, 2) to measure the extent to which soil K levels can be built up in sandy, kaolinitic soils, and 3) to correlate petiole K concentrations with cotton yields on sandy soils. Research was conducted in 1990 and 1991 on two soils (Lucy loamy sand and Lakeland sand), using three varieties (DPL90, KC31, and McNair220), and five soil K application rates (0, 50, 100. 200. and 400 lb K/A). Results showed that the current recommendations are suitable for some cultivars, but DPL90 may require a higher K fertilization rate. The 200 and 400 lb K/A application rates significantly increased soil K concentration in the top 6 inches of both soils. However, the application of 400 lb K/A increased soil K (0-6 inches) by 26.1 ppm on the Lucy loamy sand, but only increased soil K by 8.7 ppm on the Lakeland sand On the Lucy loamy sand (medium K. low Mg) petiole K was not significantly correlated with seed cotton yield, but on the Lakeland sand (low K, medium Mg), McNair220 and DPL90 had positive yield correlations with petiole K. Positive correlation of yield with petiole Mg on the Lucy loamy sand was related to Mg deficiency. Excessive K application can induce Mg deficiency and reduce yield; therefore, fertilizer recommendations should be carefully followed.



Reprinted from 1992 Proceedings Beltwide Cotton Conferences pp. 1147 - 1150
©National Cotton Council, Memphis TN

[Main TOC] | [TOC] | [TOC by Section] | [Search] | [Help]
Previous Page [Previous] [Next] Next Page
 
Document last modified Sunday, Dec 6 1998