Characteristics of Soil Nutrients Accumulation and Nitrogen and Phosphorus Loss of Greenhouse Vegetable Field

［Objective］ This study aimed to clarify the characteristics of soil nutrient accumulation and nitrogen and phosphorus loss for the greenhouse vegetable in Jiangxi Province, thereby providing scientific data for the accurate evaluation on pollution risk and promoting the healthy development of vegetable industry in this province. ［Methods］ Multipoint sampling was used for analysis cumulative amount of nutrients within the 0—100 cm depth soil layer in greenhouse vegetable throughout 11 cities and districts of this province, and in situ monitoring was used to analyze the characteristics of nitrogen and phosphorus loss. ［Results］ 1) The soil was severely acidified. The soil layers within 0—20 and 20—40 cm under surface showed pH values of 5.44 and 5.56, respectively. 2) The soil nutrient content in 0—20 cm soil layer was at the medium fertility level, and the soil nutrient increased with the extension of planting time when the planting years were less than 10 years, and began to decline when the planting years were 11—20 years (except for available phosphorus). 3) The runoff from greenhouse vegetable is mainly driven by rainfall and has the characteristics of high volume and low concentration; runoff occurs in the period from February to June accounts for more than 75% of the annual runoff amount and more than 60% of the annual nitrogen and phosphorus loss. ［Conclusion］ The 6—10 years might be a “turning point” for the cumulative contents of nutrients in greenhouse vegetable plots. Excessive use of nutrients after 6—10 years could not increase the storage capacity of the soil, but it might increase the risk of pollution caused by the accumulation of available nutrients. Due to the degenerated function of regulation, storage and purification of ditches and ponds, the generation of short-term, high-flow and low-concentration runoff water from greenhouse vegetable is difficult to be consumed in farmland ecosystem locally in at present. Therefore, the construction of greenhouse vegetable-single season rice composite farming model may be an effective means to solve the non-point source pollution of from greenhouse vegetable in red soil areas in southern China.