ABSTRACT

Three field studies were conducted to evaluate the effect of soil applied K and foliar applied K and N on Cotton yield and fiber quality when grown on heavy clay soils of the Central Blackland Prairie of Texas. Soil test K levels were rated moderate, high and very high and very high at the three locations.

Treatments included a check, soil applied KCl, soil KCl+foliar KNO₃, soil KCl+foliar N as urea and foliar N as urea without soil applied KCI. Soil KCl was applied at 60 lbs. K₂O/A. Treatments 3 and 4 consisted of soil applied KCl+10 lbs. KNO₃ (1.3 lbs. N, 4.4 lbs. K₂O) or 2.8 lbs. urea (1.3 lbs. N) per acre, respectively. Treatment 5 consisted of foliar urea alone at 13 lbs. per acre (6 lbs. N). All foliars were applied at two-week intervals on July 1 (7-10 days after first flower), July 15 and July 29.

None of the treatments resulted in yields or fiber quality parameters (grade, micronaire, length, stength) which were significantly different from the untreated check.