Effect of palygorskite coating on various forms of nitrogen urea

Static absorption and soil column leaching methods were used to study and analyze the difference of N form between from applied urea coated with three different thicknesses of palygorskite and uncoated urea. The results show that coating urea with palygorskite decreases ammonia volatilization by 10.38%~26.24% compared with uncoated urea. Coating also reduces N (NO₃^--N+N+NH₄⁺) leaching by 5.88%~27.74%. With 20% palygorskite coating treatment, urea significantly increases the NH₄⁺-N in column soil. The three different palygorskite coatings lead to a significant increase in NO₃^--N in column soil. Urea coated with palygorskite decreases ammonia volatilization and N (NO₃^--N+NH₄⁺-N) leaching, increases NH₄⁺-N and NO₃^--N in the soil. More importantly, palygorskite coating of 20% induces optimal ecological conditions.