Humus is the stable form of added crop and animal residues. The organic matter after a long-term decomposition process converts into humic substances. The naturally occurring humus is present in less amount in soils of the arid and semi-arid regions. The addition of commercially available humic acid can, therefore, contribute to improving soil health and crop yields. The present study was conducted to evaluate the effect of potassium humate, applied through soil seed dressing, on cotton productivity and fiber quality attributes. Seed dressing with potassium humate was done at the rate of 0, 100, 150 and 200 mL kg-1 seed while in soil potassium humate was applied at the rate of 0, 10, 20 and 30 L ha-1. Results showed that the combined application of potassium humate by seed dressing and through soil application improved the soil properties, productivity and fiber quality traits of cotton. All levels of soil applied potassium humate (10, 20 and 30 L ha-1) performed better over seed dressing in terms of cotton productivity and fiber quality attributes. Among the soil application rates, 20 L ha-1 potassium humate proved better as compared to other rates (0, 10 and 30 L ha-1). Higher soil application of potassium humate (30 L ha-1) showed depressing effects on all the traits studied like the reduction of 12.4% and 6.6% in Ginning out turn and fiber length, respectively, at a seeding dressing of 200 mL kg-1. In conclusion, potassium humate seed dressing and soil application at the rate of 200 mL kg-1 and 20 L ha-1, respectively, is a better approach to improve cotton productivity. Soil potassium humate should not exceed a rate of 20 L ha-1 when the seed dressing of potassium is also practiced.
Keywords: application method; biological yield; grain yield; nitrogen; phosphorus; potassium.