秸秆带状覆盖对半干旱雨养区冬小麦耗水特征和产量的影响

为探索半干旱雨养区小麦高产高效的覆盖种植技术新途径,于2013—2015年连续进行定位试验,设秸秆带状覆盖3行(覆盖带和种植带各30 cm,播种3行,SM₁)、秸秆带状覆盖4行(覆盖带和种植带各40 cm,播种4行,SM₂)、秸秆带状覆盖5行(覆盖带和种植带各50 cm,播种5行,SM₃)、全膜覆土穴播(PMF)、不覆盖露地(CK)5个处理,研究不同覆盖方式对西北雨养区冬小麦的耗水特性、产量和水分利用效率的影响.结果表明: 覆盖能显著改善作物土壤墒情,秸秆带状覆盖处理的土壤墒情好于地膜覆盖处理,且SM₁＞SM₂＞SM₃,0～2 m土壤贮水量在小麦开花期分别平均比CK高15.4%～20.8%、11.2%～14.7%和10.1%～14.5%;秸秆带状覆盖显著提高了生育期耗水量,降低了播种至开花阶段耗水量,增加了开花至成熟阶段耗水量及其占总耗水量的比例;覆盖会提高小麦对120 cm以下深层贮水的调用比例.与CK相比,秸秆带状覆盖和地膜覆盖处理籽粒产量分别显著增加11.9%～19.5%和26.9%～27.1%,水分利用效率分别显著提高9.8%～13.9%和18.4%～22.0%.因此,秸秆带状覆盖种植模式有利于降低冬小麦前期耗水比例,改善土壤墒情,显著提高冬小麦籽粒产量和水分利用效率,是适宜于西北黄土高原半干旱区冬小麦的绿色种植技术.

Effects of bundled straw mulching on water consumption characteristics and grain yield of winter wheat in rain-fed semiarid region

To explore a new technique of planting wheat with high yield and efficiency by mulching technology in rain-fed semiarid regions in Northwest China, a two-year fixed-site trail was conducted during 2013-2015. There were five mulching modes: (1) three sowing rows by bundled straw mul-ching with alternating 30-cm-wide mulching belt and planting belt (SM₁), (2) four sowing rows by bundled straw mulching with alternating 40-cm-wide mulching belt and planting belt with (SM₂), (3) five sowing rows by bundled straw mulching with alternating 50-cm-wide mulching belt and planting belt (SM₃), (4) whole plastic film mulching with dibbling (PMF), (5) bare field planting without any mulching (CK). We examined the effects of different mulching modes on water consumption, water use efficiency (WUE), and yield of winter wheat in rain-fed region in Northwest China. The results showed that bundled straw mulching significantly increased soil water storage. Soil water storage with bundled straw mulching was remarkably higher than that with the whole plastic mul-ching with SM₁＞SM₂＞SM₃. Soil water storage at 0-200 cm soil layer in flowering period was increased by 15.4%-20.8%,11.2%-14.7%and 10.1%-14.5% respectively over that in the bare field. Bundled straw mulching significantly increased water consumption during the whole growing period while reduced water consumption from sowing and flowering periods. Further, it increased water consumption from flowering to maturity periods and the ratio of water consumption during this period to the total water consumption during the whole growing periods. The results showed that mulching could increase the consumption ratio of deep water storage from the soil layer below 120 cm. Compared with CK, PMF and SM significantly increased grain yield and water use efficiency by 11.9%-19.5%, 26.9%-27.1%, respectively, and increased water use efficiency by 9.8%-13.9%, 18.4%-22.0% respectively. In all, bundled straw mulching could reduce water consumption ratio in the early growing periods, improve moisture condition, increase grain yield and water use efficiency of winter wheat. Therefore, we concluded that bundled straw mulching is an environment-friendly cultivation technology suitable for the winter wheat in semi-arid region of the Loess Plateau in Northwest China.