Soil conditioner applicable to saline and alkaline dryland sandy soil cotton field

The invention discloses soil conditioner applicable to the saline and alkaline dryland sandy soil cotton field. The soil conditioner is composed of nutrient elements (sulfur coated urea, diammonium phosphate and potassium sulphate), turfy soil, ferrous sulfate, ardealite, polyacrylamide and a drought resistance and salt tolerance agent (2-( acetoxyl group) benzoic acid and sodium nitroprusside). The soil conditioner is targeted to solve the problems that northwest inland areas are deficient in fresh water resource and poor in sandy saline and alkaline soil water and fertilizer retention capacity, the fertility characteristics of 'nitrogen deficiency, phosphorus deficiency, rich potassium' of sandy saline and alkaline soil, requirements for fertilizer of cotton and fertilizer absorption characteristics of cotton in sandy saline and alkaline soil are comprehensively considered, and comprehensive treatment is conducted from multiple angles of water retention, fertilizer retention, lowering of pH value, salt inhi