Integrated Organic and Inorganic Amendments for Improving Productivity of Okra (Abelmoschus esculentus L.) in Alkaline Soil.

SALINITY and alkaline stress pose major constraints for crop production. The use of soil amendments can help alleviate salinity and alkaline stress and improve productivity in salt-affected soils. A field experiment was conducted in 2021 and 2022 in Damietta, Egypt, to evaluate the effect of different organic and inorganic amendments on the growth, yield, quality, and nutrient uptake of okra (Abelmoschus esculentus L. cv. Balady) grown in alkaline soil. Treatments included gypsum (GP), organic matter (poultry manure; OM), fulvic acid (FA), humic acid (HA), and their combinations. The application of humic acid + organic matter + gypsum resulted in the tallest plants, the highest number of leaves, the greatest leaf area, the maximum pod yield, and increased nutrient uptake over control. It also gave the highest marketable yield, which was over 100% greater than control. The organic and inorganic amendments caused an appreciable improvement in soil properties like pH, EC, CEC and ESP. The results demonstrated that the integrated application of humic acid, organic matter, and gypsum could effectively reclaim the alkaline soil and improve the growth, yield, and nutritional quality of okra. The synergistic effects of the amendments in enhancing soil physical, chemical, and biological properties led to better plant growth and productivity under salinity stress conditions. The use of organic residues also helped sustain soil health. Despite greater amendment costs, HA+OM+GP had higher incremental yields (108-112%) over the farmer's practice of applying only organic matter and attractive returns on investment. The study showed that a holistic approach combining organic and inorganic amendments was most effective for okra cultivation in problematic soils. [ABSTRACT FROM AUTHOR]