Effects of Mulching with Wheat Straw on Soil Moisture and Heat and Growth of Sunflower

Cultivation experiment with different types of coverage of eating sunflower was carried out in 2017 based on method of combining field monitoring test with indoor mechanism test and method of combining field plot control test and theoretical analysis by taking Minqin irrigation area in northwest arid area as research area.Coverage mode had three levels of without mulch（CK），straw mulch（S）and plastic film mulch with crushed wheat straw padding（SF），and irrigation quota commonly adopted by local farmers of 900 m3/hm2 was adopted.In order to select the optimal mulching mode，soil moisture content，soil temperature of 0～120 cm and sunflower yield under different mulching methods were observed and analyzed.Results showed that，soil water storage in the whole growth period was SF＞S＞CK under different mulching methods，S and SF increased by 2.1% and 12.9% compared with CK.Soil temperature under different mulching methods decreased with increase of depth by observing ground temperature of six soil layers（0，5，10，15，20 and 25 cm）.Loss of ground temperature under S and SF was slower than that under CK，and had a certain heat preservation effect.Biomass，plant height，stem diameter and leaf area of sunflower had the same trend under different mulching methods，that SF＞S＞CK in each growth period，and moisture content of wet basis under SF was higher than other two mulching methods.Based on analysis of biological yield and soil water storage of sunflower，application of straw mulch in sunflower cultivation in experimental area had a better effect of soil moisture conservation and yield increase.