Influence of smart irrigation techniques and soil amendments on growth dynamics and yield performance of cotton in western zone of Tamil Nadu
Cotton (Gossypium hirsutum L.) is an important commercial crop and its productivity is highly influenced by efficient water and nutrient management, especially under changing climatic conditions. A field experiment was conducted during the summer and winter seasons of 2025–26 at the experimental fields of Tamil Nadu Agricultural University, Coimbatore, Tamil Nadu, to evaluate the effect of smart irrigation techniques and soil amendments on the growth and yield performance of cotton. The experiment was laid out in a strip-plot design with 3 replications. The main-plot treatments consisted of different smart irrigation techniques, viz., drip irrigation, soil moisture sensor-based drip irrigation and evapotranspiration (ET)-based drip irrigation. The sub-plot treatments comprised combinations of liquid biofertilisers (nitrogen-fixing bacteria (NFB), phosphorus-solubilising bacteria (PSB) and phosphorus-mobilising bacteria (PMB), each at 5 L ha-1), zeba at 12.5 kg ha-1 and enriched farmyard manure (EFYM) at 7.5 t ha-1. The results revealed that soil moisture sensor-based drip irrigation combined with liquid biofertilisers, zeba and EFYM significantly improved growth parameters, dry matter production and seed cotton yield during both seasons. The integrated treatment also enhanced soil moisture availability, nutrient uptake efficiency and overall crop productivity. The highest plant height (124.26 and 127.88 cm), number of sympodial branches per plant (32.11 and 30.40), dry matter production (12574 and 11745 kg ha-1), number of bolls per plant (14.0 and 13.5) and seed cotton yield (3728 and 3571 kg ha-1) were recorded under soil moisture sensor-based drip irrigation combined with liquid biofertilisers, zeba and EFYM during the summer and winter seasons, respectively. Therefore, the combined can be recommended for enhancing cotton productivity and resource-use efficiency.