Objectives Mulching cultivations can effectively improve soil physic-chemical and biological characteristics, which have played important roles in continuous improvement of soil quality and crop productivity. In this experiment, we compared the effects of several mulching ways in dryland of Weibei Rainfed Area, to make the best use of these measurements on improving crop productivity and soil fertility in this area.

Methods The experiment was conducted in winter wheat from September 2014 to June 2017 in Fuping Experimental Station, Shaanxi Province. There were four treatments, no mulching (CK), mulched with straw (NPS), plastic film (NPP) and ridge-furrow with plastic film and straw mulch (RFPS). At harvest, the soil samples of 0–20 cm and 20–40 cm depth were collected for analyzing soil nutrients, organic carbon (SOC), liable organic carbon (LOC) and enzyme activities, and wheat samples were collected for determining wheat productivity.

Results Compared with CK, the yields of the RFPS, NPP and NPS treatments were significantly increased by 51.8%, 41.3% and 13.7%, and water use efficiencies were increased by 40.9%, 34.0% and 11.2%, respectively (P < 0.05); the effects among the three treatments were significantly different as well. Compared with the CK, mulching cultivations increased N, P and K uptakes of winter wheat, especially in the RFPS and NPP treatments (P < 0.05). The contents of total N, P and K in the surface soil of RFPS were increased by 6.5%, 4.5% and 8.0%, the contents of available N, P and K were increased by 46.1%, 37.8% and 19.5%, SOC content increased by 5.1% and LOC increased by 15.1%, and the activities of invertase, urease and phosphatase increased by 24.6%, 34.6% and 27.4%, respectively (P < 0.05); and all the increases were significantly higher than those of the NPP and NPS (P < 0.05). The NPP treatment increased the invertase activity by 9.6% in surface soil (P < 0.05), but did not increase significantly the contents of soil nutrients, SOC and other enzyme activities in 0–40 cm layer, and even reduced the contents of total N and SOC, compared with the CK. The NPS treatment increased the contents of available N, P and K by 22.7%, 19.9% and 15.0% (P < 0.05), SOC by 4.1% and LOC by 12.5%, and the activities of invertase, urease and phosphatase by 12.0%, 15.5% % and 12.0%, respectively. However, the NPS treatment had little effects on the contents of total N, P and K in 0–40 cm soil layer.

Conclusions The mode of ridge-furrow with plastic film and straw mulch performs well in increasing winter wheat productivity and soil fertility in dryland of Weibei Rainfed Area, and can be recommended in local agricultural production for the test area.