Plastic film mulching combined with nutrient management to improve water use efficiency, production of rain-fed maize and economic returns in semi-arid regions

To examine the combined effects of planting models with nutrient management strategies on grain filling rates, productivity, soil water storage, water-use efficiency and economic benefit of rain-fed corn, there for a field research was carried out during 2015–2016 in a semi-arid region of China. Three planting models were tested: ridge furrow system with plastic mulching (M1), furrow planting with soil crust ridges (M2), and flat planting without plastic mulching (M3); in combination with four nitrogen levels: 0 kg ha–1 (N0); 100 kg ha–1 (N1); 200 kg ha–1 (N2), and 300 kg ha–1 (N3). We found that M1 planting model with higher 300 kg-1 N ha-1 could significantly increase soil water availability at different growth stages, as a result significantly increased WUE (56.6%), RUE (71.2%), ET (8.8%), soil water storage, biomass (35.5%), and grain yield (70.8%) of rain-fed maize than that of M3N0 treatment. Increasing the nitrogen level as a result significantly increased the economic benefit, yields and yield components of rain-fed maize under different planting models, but AEN shows a significantly decreasing trend. The M1N3 treatment significantly promoted the LAI and grains filling of the basal, middle and upper seeds than that of M2 and M3 cultivation models with the highest nitrogen level. The M1N3 treatment obtained the highest (12,775 CNY ha-1) net profit, improved the SWS throughout the grain-filling duration, which resulted in higher productivity. Thus, M1N3 treatment can be used to improving productivity, economic benefit, and water use in semi-arid areas.