Effects of sludge tail product amendments on improvement of soda saline-alkali soil

Aiming at the characteristics of high salinization and exchangeable sodium ion in soda saline-alkali soil, a new type of sludge tail product amendment was selected to improve the saline alkali soil. A pot experiment was conducted to compare the effects of different amounts of new amendments on soil properties and crop growth. The results showed that the alkalinity, exchangeable Na⁺ content, SAR and pH of the soil were significantly reduced, and the physical and chemical properties of the saline alkali soil were improved after amendments applied. At the same time, the contents of available nitrogen, available phosphorus, available potassium and soil organic matter were significantly increased, which provided sufficient nutrients for maize growth. In addition, the amendment treatments promoted crop growth, effectively improved plant height, stem diameter and SPAD, with an increase of 18.8% ~ 41.9% in yield. The treatment with 22.5 t·hm⁻² of amendments had the best comprehensive effect on the physical and chemical properties of saline alkali soil and yield increase. The sludge tail product amendment can improve the maize yield by optimizing the soil environment and promoting crop growth, and is an effective method to improve saline alkali soil. The results provide a theoretical basis for the future resource utilization of sludge and the improvement of soda saline-alkali soil.