Experimental Study on Runoff and Erosion Under Conservative Tillage

A field experiment was conducted on loess farmland in Northwest China to test different conservative tillage systems, and to compare them with conventional moldboard plough practice (CK) in terms of their effects on runoff and soil erosion. The effects of tillage, covering and compaction on runoff and erosion were also studied. Six treatments were laid out with tipping buckets and electronic data loggers that measured the rates of rainfall and runoff synchronously as a function of time. Total soil loss, divided into bed load and suspended load, was measured annually. Results of two years showed that slope runoff and erosion were highly dominated by rainfall pattern or rainfall intensity. Under heavy storms, conservative tillage, which features more residue cover and less soil disturbance, could remarkably reduce runoff and erosion compared to CK; while without residue cover, no tillage or minimum tillage could produce more runoff and erosion than CK. Among the six treatments No-tillage with residue Cover and No Compaction(NTCN) was the best one in terms of soil and water conservation. It was able to reduce runoff by 52.5% and erosion by 80.2% compared to CK. Residue cover is more efficient for soil and water conservation, which was able to reduce runoff by 47.3% and erosion by 7.6%. Compaction also had considerable impact on runoff and erosion, while the effect of surface tillage was not so obvious since it reduced residue cover while loosening surface soil.