Crops in the northwest arid region of China frequently suffer from low emergence and poor yield due to high water deficit. Mulching is an important approach to reduce irrigation amount while increasing productivity but faces challenge of ecological adaptability in this region. A field experiment was carried out in the three growing seasons from 2011 to 2013 to study effects of mulching with crushed wheat straw padding and plastic film on sunflower seed emergence and yields under different irrigation intensities. A two factor (mulching, irrigation intensity) completely randomized block design was applied, resulting in a total of 12 treatments repeated three times. Mulching treatments includes: zero mulch (N), straw mulching at the beginning of trial (S), plastic film mulching when sowing (F), a commonly used mulching by local farmers, and double mulching with plastic film on the crushed wheat straw layer (SF). Irrigation intensity includes: High (H=900 m3 ha-1), Medium (M=750m3 ha-1), Low (L=600m3 ha-1). Results showed that all mulching treatments promoted early emergence of seedlings compared with N, with SF and F performing the better than the rest. SF was the best-performing mulching approach in this study, and had significantly improved sunflower yield and yield components compared with other treatments. In SF, medium irrigation level had significantly increased sunflower 100-seed weight. Therefore, SF with medium irrigation level showed the most positive effect on sunflower production and in now the recommended agronomic solution for sunflower production in the northwest arid regions and potentially, other irrigated areas with similar ecological conditions.
