On the semi-arid Loess Plateau of northern China, water is typically the biggest constraint to rainfed wheat production. Controlled traffic, combined with zero tillage and residue cover has been proposed to improve soil water, crop yield and water use efficiency. From 1998 to 2005, we conducted a field experiment comparing the water storage and wheat productivity of controlled traffic farming and conventional tillage farming. Three treatments were studied: controlled traffic with no tillage and fullresidue cover (NTCN), controlled traffic with shallow tillage and full residue cover (STCN) and random traffic with traditional tillage and partial residue cover (CT). Compared to CT, the controlled traffic treatments significantly reduced soil bulk density in 10–20 cm soil layer, significantly increased soil water content in the 0–150 cm soil profile at sowing, 9.3% for NTCN, 9.6% for STCN. These effects were greater in dry seasons, thus reducing the yearly variation in water conservation. Consequently, mean wheatyieldofNTCN,STCNandCTwere3.25,3.27and3.05 t ha1,respectively,inwhichcontrolledtraffic treatments increased by 6.9% with less yearly variation, compared to traditional tillage. Furthermore,controlled traffic had greater economic benefits than conventional tillage. Within controlled traffic treatments, NTCN showed better overall performance. In conclusion, controlled traffic farming has a
better performance with respect to conserving water, improves yields and increases economic benefits.No tillage controlled traffic farming appears to be a solution to the water problem facing farmers on the Loess Plateau of China.