Sustainable Management of Saline Soils by Using Organic and Inorganic Amendments: Implications for Wheat Growth and Production

Abstract

Soil salinity is a major constraint to agricultural productivity in Pakistan, affecting approximately 6.68 million hectares of irrigated land and significantly limiting wheat production. This study evaluated the integrated effects of compost, gypsum, and bentonite on soil physicochemical properties and wheat performance under saline conditions. A pot experiment was conducted using a completely randomized design with five treatments and three replications, including a control, recommended NPK fertilizer, and different amendment combinations. The combined amendments significantly (P < 0.05) improved soil properties compared with the control and NPK treatment. The treatment comprising 50% compost + 5% gypsum + 5% bentonite reduced soil electrical conductivity by 34% and decreased pH from 8.59 to 8.14, indicating effective salinity mitigation. Treatments with higher compost proportions significantly increased soil organic matter by 87% and enhanced available phosphorus and potassium. Improve soil conditions translated into enhanced crop performance. Integrated treatments increased germination by 26%, chlorophyll content by 42%, grain yield by 39%, and 100-grain weight by 82% relative to the control. Plant nitrogen and potassium uptake were also substantially improved, particularly under the 75% compost + 3% gypsum + 5% bentonite treatment. In contrast, recommended NPK fertilizer alone had minimal effect under saline conditions. Overall, the combined application of compost, gypsum, and bentonite demonstrated synergistic benefits in mitigating salinity stress and improving wheat productivity, highlighting its potential as a sustainable strategy for rehabilitating salt-affected soils.