The production of compound fertilizers often uses soil testing formulas to measure the nutrient status of the soil. Soil testing formula fertilization is based on soil testing and fertilizer field experiments, and proposes the application quantity, fertilization period, and application method of nit

According to fertilizer scienceA considerable portion of compound fertilizers sold in the market do not meet the national DB15063-94 standard. According to national standards, the effective nutrient content of compound fertilizer (compound fertilizer) should be ≥ 40% for high concentration nitrogen,