Effective strategies for reclaiming soda-saline soils: Field experimentation and practical applications in Southeast Kazakhstan

Soda-saline soils pose significant challenges to agricultural productivity, particularly in regions like the foothill plain of the Ili Alatau in southeast Kazakhstan. In this study, we examined the effectiveness of different ameliorants, including phosphogypsum, elemental sulfur, and sulfuric acid, in reclaiming soda-saline soils and enhancing crop yields. The study was conducted under real climatic and production conditions at the "Amiran" LLP farm. Using a randomized complete block design, we assessed the impact of these ameliorants on soil composition and alfalfa yield over two cutting cycles. The experiment involved the application of phosphogypsum, elemental sulfur, and sulfuric acid to designated plots within the farm, each covering an area of 15m2. Soil samples were collected before and after treatment to assess changes in soil composition and salinity. Alfalfa, a resilient perennial crop, was selected for cultivation due to its tolerance to adverse soil conditions. Our findings reveal that all tested ameliorants successfully neutralized the toxic environment of soda-saline soils, resulting in improved soil conditions and increased crop productivity. Phosphogypsum treatment led to a reduction in bicarbonate and carbonate ions, an increase in sulfate ion concentration, and improved soil structure. Elemental sulfur incubation decreased bicarbonate and carbonate ions, further reducing absorbed sodium levels and enhancing soil fertility. Sulfuric acid treatment provided rapid results in reducing alkalinity and increasing sulfate ion concentration, leading to significant improvements in soil quality and crop yield. However, the reclamation of soda-saline solonetzes presented challenges related to soil heterogeneity and poor water permeability. To address these challenges, we recommend the implementation of mechanical destruction of the solonetz soil horizon and deep soil loosening, accompanied by the addition of ameliorants. In conclusion, our study demonstrates the potential of phosphogypsum, elemental sulfur, and sulfuric acid as effective ameliorants for reclaiming soda-saline soils and improving agricultural productivity in challenging environments. By adopting recommended reclamation strategies, farmers can overcome soil limitations and achieve sustainable crop production in regions affected by soda-saline soil degradation.