Optimizing Cotton Yield through Macronutrient Mixtures

An incubation study, followed by a two-year field trial, was conducted at Tamil Nadu Agricultural University (TNAU), Coimbatore, to comprehensively assess the nutrient release and the effect of macronutrient fertilizer mixtures on nutrient uptake, nutrient use efficiency, cotton quality parameters, and crop yield during 2020 to 2021. The study aimed to identify the best fertilizer combinations of nitrogen (N), phosphorus (P), and potassium (K) sources to enhance cotton growth and productivity. The treatments, all involving 100% Recommended Dose of Fertilizers (RDF), comprised the following macronutrient mixtures: T1 (Urea + DAP + MOP), T2 (Urea + SSP + MOP), T3 (Urea + DAP + SOP), T4 (Urea + MAP + SOP), T5 (CN + DAP + MOP), T6 (CN + DAP + SOP), T7 (Urea + CN + SSP + MOP), T8 (CN + ASP + MOP), and T9 (Absolute Control). The incubation study provided insights into the nutrient release pattern from the different fertilizer mixtures over time. The two-year field trial confirmed that the application of a fertilizer mixture containing CN, DAP, and MOP (T5) significantly increased nutrient uptake T5 and agronomic use efficiency in cotton. The yield increase due to this particular treatment was 66.7% and 67.9% higher than the control during 2020 and 2021, respectively. Incorporation of sulfur-containing fertilizer mixtures, such as CN with DAP and SOP (T6 ), and urea with DAP and SOP (T3), markedly increased protein and oil content in cotton seed. Different fertilizer sources had no significant effect on lint quality parameters. Application of tailored macronutrient combinations to cotton plants improved nutrient uptake and yields, highlighting the practical benefits of strategic fertilizer application.