Abstract:Soil moisture and nitrogen are two major factors that limit wheat yield in northern China. Previous studies have investigated the effects of different film mulching methods on soil water, nitrogen balance, and yield in dryland wheat fields. The present study consisted of four treatments, including farmer mode (no film mulching), a control treatment (no film mulching), and two film mulching methods, either ridge film furrow sowing or flat film dibbling. We aimed to identify a suitable film mulching method for Loess Dryland Plateau and to establish a theoretical basis for producing high-yield and high-quality wheat in southern Shanxi, as well as in other areas in China. The results indicated that ridge film furrow sowing and flat film dibbling increased winter wheat yield and that the effect of flat film dibbling was greater. Compared with the control treatment, the grain and biological yields of the flat film dibbling treatment increased by 22.71% and 25.45%, respectively, and grain yield was also positively correlated with spikes per hectare (correlation coefficient=0.838), indicating its importance in increasing grain production. The water consumption of ridge film furrow sowing and flat film dibbling treatments were higher than the other treatments during the whole growth period, whereas their water use efficiency was slightly lower, although not significantly. Interestingly, compared to the farmer and control treatments, film-mulched winter wheat absorbed more water from deep soil (100-200cm). More specifically, the deep soil water that was consumed by the ridge film furrow sowing wheat accounted for 48.88% of the total soil water storage, whereas that of the control treatment only accounted for 35.75%. Plastic film mulching also increased the rainfall production and leisure efficiencies of wheat fields by 9.46%-30.16% and 9.95%-39.22%, respectively. Plastic film mulching promotes the mineralization of nitrogen, which can promote the absorption and utilization of nitrogen by wheat, reduce the residual nitrogen of soil, and increase the yield of winter wheat. Overall, both ridge film furrow sowing and flat film dibbling effectively improved the uptake and utilization of soil water and nitrogen by winter wheat, thereby increasing the yield of winter wheat. The observation that film mulching promotes the utilization of deep soil water by winter wheat should be investigated further, so as to better evaluate characteristics of soil moisture consumption in different soil layers.