Effect And Mechanism Of Soil And Water Conservation Of Contour Hedges In Red Soil

Contour hedgerow intercropping is regarded as an effective and low-cost technology for conserving farming and sustainable use of sloping land. Five patterns of contour grass hedgerows were planted in the run-off plots for experiment, combined with the methods of rainfall simulation, rare earth elements tracing technique (REE) was used to study effects and mechanism of soil and water conservation of contour grass hedgerows in red soil slop field in Zhuji, Zhejiang province. The results showed that runoff and soil loss were all significantly reduced by Double-row Ophiopogon japonicas by40%and60%respectably. The soil water content of before rainfall has significant impact on the total runoff and soil loss of rainfall. Regression models were established to simulate the relationships between runoff and soil loss. The changes of soil physical property under different patterns were significant, and the analysis show that the bulk density and porosity could be used as the premier indicators to estimate the soil anti-erodibility. Finally seventeen indicators were used to establish the red soil anti-erodibility index system. Applying the index system, the comprehensive anti-erodibility of each pattern was calculated and compared: Double line of Ophiopogon japonicas (MM)> Combination of Ophiopogon japonicas and Hemerocallis citrina (MM)> Double line of Hemerocallis citrina (HH)> Single line of Ophiopogon japonicas (M)> Single line of Hemerocallis citrina (H)> Plot without treatment(L). The middle and down slopes were the major source of sediments, and the anti-erodibility which was affected by hedgerows was different among up, middle and down slope.