Effect of soil and foliar application of humic acid on cotton yield and soil fertility in Vertisols

Abstract

The present study was conducted during the year 2024-25 at Research Farm, Department of Soil Science, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola, to evaluate the effect of soil and foliar application of humic acid on yield of cotton and available nutrients in soil. The experimental soil was characterized as Montmorillonitic, hyperthermic, with high clay content and typical swell-shrink behaviour. The experiment comprised seven treatments arranged in randomized block design with three replications. The highest seed cotton yield was recorded with application of 100% RDF through soil + foliar spray of EnHA @ 0.5%, which was statistically at par with treatment receiving 75% RDF through drip + EnHA @ 0.2% through drip. The highest stalk yield of cotton was obtained with application of 100% RDF through drip, which was statistically at par with the treatments receiving 75% RDF through drip + EnHA @ 0.2% through drip and 75% RDF through drip + HA @ 0.2% through drip. The lowest seed cotton yield and stalk yield were in control. A significant improvement in soil organic carbon (SOC) was recorded with the application of 75% RDF through drip + HA @ 0.2% through drip followed by 75% RDF through drip +EnHA @ 0.2% through drip. In terms of available nutrient status, the significantly highest available nitrogen and available phosphorus were found with 75% RDF through drip + EnHA @ 0.2% through drip, followed by 75% RDF through drip + HA @ 0.2% through drip. Similarly, the highest available potassium and available sulphur were also observed with 75% RDF through drip + EnHA @ 0.2% through drip.