Soil phosphorus loss is one of the sources of agricultural non-point source pollution. In the study

the characteristics of total phosphorus loss and the effects of vegetation coverage

fertilization and slope length on total phosphorus loss were examined. The red soil of slope land in hilly area of Zhejiang Province was studied with different vegetation coverages (0

15%

30%

45%

60%

75% and 90%) and slope lengths (1

2

3

4 and 5 m) and fertilization treatments (CK

CF and OF)

and the experiment was designed under simulated rainfall condition of 30 min

rainfall intensity of 120 mm/h and fixed slope of 20°. The main conclusions were showed as follows: (1) In the condition of different fertilization treatments and slope lengths

total phosphorus loss in per unit projected area decreased with the increase of vegetation coverage. The decreasing trend on the 1 m slope length was not obvious

while the trend on the 5 m slope length was fairly obvious. Total phosphorus loss in per unit projected area was the least when the vegetation coverage was 90%

and the maximum occurred on bare land. (2) In the condition of different fertilization treatments and the same vegetation coverage

the increment of total phosphorus loss between adjacent slopes was the lowest at 3～2 m and the highest at 4～3 m. The results showed that the critical slope length was 4 m and the optimal slope length was 3 m. (3) In the condition of different fertilization treatments and slope length

eroded phase phosphorus accounted for 30.24%～94.61% of total phosphorus output

and the proportion were all higher than 50% except for the 1 m slope length

indicating that erosive phosphorus were the main form of total phosphorus loss. (4) In no fertilization condition

the ratio of erosive phosphorus to total phosphorus output was higher than that treated with inorganic fertilization or organic fertilization. Compared with the application of inorganic fertilizer

the ratio of erosional phase to total phosphorus output was higher under the condition of organic fertilizer.