Combinations of N rates with previous crops were used to obtain a range of N fertility levels at Brewton and Prattville Experiment Fields in Alabama. The soils were Benndale sandy loam at Brewton and Lucedale sandy loam at Prattville. Pix was applied at 0 and 1.5 pt/acre (I pt at bloom and 112 pt 14 days later). Nitrogen rates ranged from 0 to 120 lb/acre. The test was conducted for 2 years. In both years and at both locations, plant heights increased with increasing N rates. Pix reduced plant heights as much as 16 inches but there was no interaction between Pix and N rates. Cotton following soybeans was taller than cotton following cotton, and Pix reduced plant heights more when cotton followed soybeans. At Prattville in 1984, there was no difference in yields between previous crops; yields averaged 306 lb/acre higher with than without Pix; optimum N rate was 120 lb/acre without Pix (4370 lb/acre) and 90 lb/acre with Pix (4550 lb/acre). At Prattville in 1985, yields were 488 lb/acre higher for cotton following soybeans than for continuous cotton and 340 lb/acre higher with than without Pix; best N rate was 120 lb/acre for continuous cotton and 90 lb/acre for cotton following soybeans. At Brewton, yield response to treatments was similar each year; Pix reduced yield of continuous cotton as much as 400 lb/acre but had no effect on cotton following soybeans; best N rate was 90 lb/acre regardless of previous crop.