| In order to clarify the effect of straw mulching rates on soil moisture, summer maize water consumption, upper dry matter, yield and water use efficiency, a two-year field experiment with the method of ridge covered by film and furrow covered by straw was carried out from June to October in 2015 and 2016. Straw mulching application rates of 0(CK), 2 500(M1), 5 000(M2), 7 500(M3) kg·hm-2 and 10 000(M4) kg·hm-2 were used in field plots. The results showed that soil moisture decreased and water consumption increased under all of the straw mulching treatments compared with that under CK. The average soil moisture in two years under the four different rates of straw mulching were1.93, 5.23, 9.47 mm and 11.54 mm lower than that of CK, at the same time, water consumption were 0.51, 3.37, 8.78 mm and 11.01 mm higher than that of CK, especially M3, M4 in two years and M2 in 2016 were significant (P<0.05) than CK. Upper dry matter with mulching was lower than CK at seedling period, while higher for other periods. The average upper dry matter in two years were 4.67%、16.58%、21.99% and 23.36% higher than that of CK, especially M2, M3 and M4 were significant than CK. The yield and water use efficiency of M3 were better when the effective use of straw was taken into consideration. When compared with CK, M1 and M2, the average yield under the treatment of M3 increased by 18.80%, 14.13% and 8.14%, average water use efficiency was increased by 14.80%, 10.92% and 5.11%, respectively. Although the average yield of M4 was increased by 1.77% and water use efficiency increased by 0.26% than M3, the results of the analysis showed that M3 and M4 did not have significant difference in two years, which mean that the rate more than 7 500 kg·hm-2 had no significant effect on increasing the efficiency of straw. Overall, it could be concluded that the treatment with 7 500 kg·hm-2 of straw mulching under dual-mulching of ridge and furrow was preferable in arid and semi arid areas and also helpful to improve the efficiency of straw utilization. |