Biomass accumulation and nitrogen fertilization in cotton under salinity stress

This investigation is part of an integrated research program on cotton responses to nitrogen fertilization in saline environments, alongside complementary studies on plant morphology, physiology, and yield components. This study investigates the effect of nitrogen fertilizer rates on the dry matter accumulation of cotton (Gossypium hirsutum L.) grown in soils with different salinity levels. In precision agriculture, soil salinity is a major abiotic stress factor reducing agricultural productivity, especially in arid and semi-arid regions. Under saline conditions, nutrient uptake, particularly nitrogen, is often impaired, negatively affecting plant growth. Optimizing nitrogen fertilization can improve plant tolerance to salinity and increase biomass production. The experiment was conducted under four salinity conditions ranging from non saline to highly saline. Cotton plants received a base application of 175 kg/ha phosphorus and 125 kg/ha potassium (P175K125), with varying nitrogen rates from 0 to 350 kg/ha. Control variants received no fertilizer. Results showed that dry matter accumulation in all plant parts, including stems, leaves, buds, and bolls, was positively affected by increasing nitrogen application. The N250 kg/ha treatment was the most efficient, providing substantial dry biomass across all salinity conditions while maintaining cost effectiveness. The results indicate that tailored nitrogen management can enhance cotton productivity, optimize resource use, and improve plant resilience under saline conditions, directly contributing to the development of predictive tools for sustainable crop management.