This paper presents the first three years of a four year study of the effect of potassium rates and placement systems on lint yield of four varieties. The study was conducted on a Buelah and Bosket very fine sandy loam potassium deficient soil with 5.9 pH values or higher.

Three fertilizer rates (80, 120, and 160 lb K₂O/A) and three placement systems (surface, deep banded, and split - 50% surface and 50% deep banded) were applied to four varieties (DES 119, DP 50, St 453, and C-130) to study their effect on lint yield.

All nine potassium fertilizer treatments increased lint yields over the check treatment for all four varieties. The deep 160 lb K₂O/A increased lint yields in DES 119 over all three surface broadcast incorporated treatments. The higher rate, 160 lb K₂O/A, of potassium produced higher lint responses than the 80 lb K₂O rate. Over the 3 years, DES 119 responded better to deep placement than either ST 453 or DP 50. Also, DP 50 and C-130 responded better to split treatments than St 453.