Studies Of Changing Trend On The Nutrients Of Mango Orchards Soil In Hainan Province

The study of soil nutrient changes in mango orchards could help to understand the difference of soil nutrient in different mango planting area, so as to carry out some reasonable and efficient fertilization measures. In this experiment, soil samples were collected from mango orchards in Ledong,Dongfang, Lingshui and Sanya of Hainan Province during the period of 2015-2016. There are 14 kinds of soil nutrient indexes such as pH, organic matter,N,P,K,Ca, Mg, S, Fe, Mn, Zn, Cu, B and CEC were measured, and the differences between the experimental groups and control groups in different soil layers were analyzed. The results are as follows:(1): The soils in mango planting areas in Hainan Province are acid,long-term fertilization led to soil acidification.(2): The soil organic matter content in the four planted areas are higher than that in the unplanted areas.(3): The content of alkaline hydrolysis nitrogen, available phosphorus and available potassium are significantly higher than that in the unplanted areas. The content of soil nitrogen is very scarce, but the content of phosphorus and potassium is relatively rich,so pay attention to reasonable increase nitrogen fertilizer, control of phosphorus, potash fertilizer.(4): After long-term planting of mango, the contents of exchangeable calcium and exchangeable magnesium in the four planted areas are higher than that in the unplanted areas, but the increase or decrease rule in content of soil available sulfur is not obviously. So we should be carefully topdressing calcium,magnesium, sulfur fertilizer.(5): After long-term planting of mango, the contents of available iron and available boron in the four planted areas are higher than that in the unplanted areas, the contents of available zinc in the four planted areas are lower than that in the unplanted areas, but the increase or decrease rule in content of soil available manganese and available copper is not obviously. Overall, the contents of trace element in the four areas are more reasonable, so we should be carefully topdressing trace element fertilizer alone so as to avoid the poisoning.(6): The capacity of soil fertility and buffer in Dongfang area is lower than Ledong, Lingshui and Sanya areas; this should be noted in the fertilization time.