Soil Applied Potassium Combined with Foliar Application of Macro and Micronutrients Improved Yield and Economic Returns of Cotton (Gossypium hirsutum L.)

Abstract Improper or inadequate mineral nutrition is a major issue in cotton ( Gossypium hirsutum L.) production globally. Therefore, the development of balanced fertilization strategies is essential for sustainable cotton production. This study assessed the impacts of soil-applied potassium (K) doses (K 0 = 0, K 70 = 70, K 140 = 140, and K 210 = 210 kg ha − 1 ) combined with water (F 0 = control) foliar-applied humic acid (F 1 = 150 g humic acid in 100 L water), micronutrients (F 2 = (250 g of micronutrient mixture containing 7% iron (Fe), 7% zinc (Zn), 1% boron (B), 5% manganese ( Mn), 0.05% molybdenum (Mo) and 1% copper (Cu) in 100 L water), and macro + micronutrients (F 3 = 500 g urea + 500 g potassium sulfate + 100 g zinc sulfate + 100 g F 2 in 100 L water) on yield-related and fiber quality traits, and ginning outturn of cotton during 2020 and 20201. Frequently cultivated genotype ‘Fiona’ was used in the study. The K was applied at the time of sowing, whereas foliar treatments were applied at square initiation, flowering initiation, and peak flowering. The individual and interactive effects of soil-applied K and foliar applied nutrients significantly altered yield and related traits, whereas fiber quality traits remained unaffected during both years. Overall K 210 × F 3 interaction resulted in the highest values of yield-related traits and seed cotton yield. The highest seed cotton yield (6428 and 6185 kg ha − 1 during 2020 and 2021, respectively) was recorded for K 210 × F 3 interaction. Similarly, K 210 × F 3 interaction resulted in the highest net returns (709 and 496 US$ ha − 1 during 2020 and 2021, respectively) and benefit: cost ratio (1.90 and 1.50 during 2020 and 2021, respectively). Overall, the highest seed cotton yield and economic returns were recorded for K 210 × F 3 interaction. Therefore, it is recommended to apply 210 kg ha − 1 K followed by foliar application of macro + micronutrients for higher yield and economic returns.