[Characteristics of phosphorus losses from slope field in red soil area under different cultivated ways]

A study on the properties of phosphorus loss under different cultivated ways was conducted in Lanxi Water and Soil Supervision Conservation Station of Zhejiang Province in 2000. The results showed that the phosphorus lost mainly through bed load and runoff. Phosphorus lost through runoff accounted for 55.26% of total lost phosphorus in straight farming field, but in other farming field, phosphorus lost with runoff accounted for 67.59%-88.11%. Particle phosphorus was the major form of the lost phosphorus, which contributed to 57.79%-77.59% of total lost phosphorus. The runoff most phosphorus was available phosphorus. Comparing with the traditional cultivated ways in the local area(treatment 5, stright farming field), the alternative different cultivated ways reduced soil phosphorus loss by 40.73%-84.70%, the contour, contour dam and fallow had better effect on controlling loss of phosphorus than the contour ditch and contour grass strip. In a year of 2000 most of the lost phosphorus was occurred during May to August accounting for 89.15%-100% of total lost.