Leaching Pattern of Phosphorus in Litchi Orchard Soil in Hainan
In order to understand the phosphorus leaching characteristics of different litchi orchards,and provide reference for fertilization management and agricultural non-point source pollution prevention and control of litchi orchards.Four kinds of litchi orchards with different soil parent materials in northeastern Hainan were selected.Through sampling investigation and indoor analysis,the soil nutrient status,soil phosphorus leaching and dissolution,surface runoff phosphorus content,etc.of litchi orchards were compared and studied.The results showed that soil available phosphorus in litchi orchard accumulated differently,and the sequence of soil available phosphorus accumulation in litchi orchard of different parent materials was:shallow sea sediment>coastal sediment>granite>basalt.The amount of leaching phosphorus,dissolved phosphorus and the concentration of phosphorus in runoff from different parent materials were consistent with the content of soil available phosphorus.The total phosphorus concentration in the runoff of the four litchi orchards exceeded 0.02 mg/L,which led to the risk of water bodies,especially the soils originated from shallow sea sediments and coastal sediments.The risk of phosphorus leaching in the soil of litchi orchards with high available phosphorus content and large sand content was extremely high.