Abstract:To relieve the characteristic conflict that the extremely scarce water resource cannot satisfy the large water requirement for wheat and maize double cropping production in the North China Plain (NCP), a field experiment was conducted in Xinji County and Shenzhou County which are located in Hebei Plain and represent the northern part of the NCP. Under conventional (-PM) and SUPM (+PM) conditions, two cropping systems were set, which were a conventional annual winter wheat-summer maize double cropping system (W-M) and a winter wheat-summer maize-spring maize triple-cropping system over 2 years (W-M-M), respectively. The results indicated that under SUPM the average wheat grain yield decreased by 3.9%~4.8%, and that of summer maize increased by 5.1%~6.0% compared with un-mulching treatment. There was no significant difference between SUPM and no mulching in total yield in the 1st year. Compared with summer maize, the spring maize yield increased by 16.9%~24.6%. Howerer, in a 2-year cycle the triple cropping system sacrificed 13.4% of grain yield compared with the double cropping system. The average annual evapotranspiration (ET) of the conventional double cropping was 859.9 mm. Under the triple cropping system over 2 years, the ET was decreased by 15.5% and the water use efficiency (WUE) was not increased significantly due to its lower yield compared with the conventional double cropping. SUPM led to an annual ET decrease of 200 mm, and the WUE increased by 28.4%~36.0%. The results also demonstrated that SUPM was better at water saving in the winter wheat season than in the summer maize season. Reduced ET in the non-growing period (the gap from the previous summer maize harvest to subsequent spring maize sowing) was also the key factor for water saving under the triple cropping system. The field water deficit was 616.6~799.0 mm in the conventional double cropping over a 2-year cycle, and it was decreased by 38.6%~55.8% in the triple cropping without SUPM. Under SUPM the field water deficit was 56.8%~73.5% lower than that under non-SUPM treatments. In the triple cropping system under SUPM, both groundwater and field water balance were almost achieved with an average annual precipitation of over 560 mm. SUPM and reducing harvest frequency could balance the vertical distribution of soil water and reduce water loss near the soil surface. The triple cropping system under SUPM over 2 years could be regarded as a new method for sustainable agricultural water utilization and food production in NCP.