Analysis on Nutrient Loss of Purple Soil under Simulated Rainfall

Nutrient loss of a purple soil under the conditions of different rainfall intensity and slope degree was studied in Chngqing,using a US-made simulated rainfall device. The results showed that the nutrients of the purple soil were lost mainly in their insoluble forms in the sediment and only a small amount was lost in their soluble forms in the runoff. The nutrient content in the sediment decreased with increasing slope; however,slope degree and rainfall intensity did not affect runoff. Nutrient enrichment in the sediment resulted in higher soil nutrients in it than those before the rainfall and in the runoff. As available nutrients were enriched in the runoff,the nutrient loss in the runoff should not be ignored.