Effect of long-term applying inorganic fertilizers with SO42- or Cl- on nutrients and adsorb-desorption in paddy soils

The influences of pH, nutrient situation and absorb-desorption of paddy soil after 22 years long-term experiment of applied inorganic fertilizers with SO42- or Cl- were studied. The results showed that when applied inorganic fertilizers containing SO42-, there were higher contents of organic matter and available N and K, but the contents of total N, P, K were all relative lower. While long-term application of inorganic fertilizers containing Cl-, the contents of total N, P, K and available P were higher, but the pH value was lower. It was advantage to increased the largest adsorption capacity of H2PO4- by applying inorganic fertilizers with SO42- or Cl- for long-term in paddy soil. There was a greater K value of adsorbed H2PO4- by paddy soil when application of inorganic fertilizers containing Cl-, but the desorption amount of H2PO4- was larger in equal absorption capacity range by paddy soil when applied inorganic fertilizers containing SO42-. Long-term application of inorganic fertilizers containing SO42- was useful to increasing the buffering and supplying power to K+, while the effects were just opposite for applying Cl- fertilizers.