水分不足是限制半干旱雨养作物生长的主要因素, 地表覆盖能够改善土壤的微环境, 从而显著提高作物的产量和水分利用效率。为明确西北半干旱雨养区不同保墒措施下旱地马铃薯的土壤水分特征及其对产量的影响, 于2014—2015年设置了玉米秸秆带状覆盖种植(T1)、半膜大垄(T2)、全膜双垄(T3)和露地平作(对照, CK) 4种栽培模式, 研究了玉米秸秆带状覆盖、地膜覆盖种植对马铃薯产量、土壤水分变化及其利用效率的影响。结果表明: 不同覆盖方式能有效改善马铃薯生育期0~200 cm土层土壤水分状况, 地膜覆盖对马铃薯生育前期土壤水分保蓄效果较好, 秸秆带状覆盖对生育中后期土壤水分状况的改善效果明显。与对照(CK)相比, 3种覆盖处理均提高了土壤含水量, 其中T1处理效果最好, 较CK提高2.8%~7.8%, 尤其在伏旱阶段的块茎形成期, 0~200 cm土层土壤含水量高于地膜覆盖处理。与CK相比, T1处理马铃薯产量提高10.5%~34.2%, 水分利用效率(WUE)提高8.9%~29.8%, 达108.9~134.0 kg·hm-2 ·mm-1, 商品薯率提高14.7%~38.8%, 达82.3%~92.2%。马铃薯产量与生育期耗水量(r=0.836**)呈显著正相关。T1的产量和商品薯率均显著高于T2和T3(P<0.05)。可见, 玉米秸秆带状覆盖具有显著的纳雨保墒作用, 促进马铃薯的生长发育, 增产效果显著。其推广应用可有效提高该区降水资源的利用效率, 实现马铃薯稳产高产, 可作为西北雨养农业区旱地马铃薯生产的高效栽培新模式。
Water deficiency is the main factor limiting crop growth in semiarid regions under rain-fed agriculture. Mulching can improve soil micro-environment and thus significantly increase crop yield and water use efficiency. In order to evaluate the effects of different strategies of soil-moisture conservation on soil water content and potato yield in semiarid regions under rain-fed agriculture in Northwest China, four mulching modes — maize-straw strip covering on no-planted ridge (T1), plastic film mulching on planted ridge only (T2), plastic film mulching on both planted ridge and no-planted furrow (T3) and flat field planting without mulching (CK) — were set in potato cultivation in 2014–2015. Potato yield and water use efficiency (WUE), and soil water content were investigated. The results showed that mulching greatly improved soil water storage at the 0200 cm soil layer during potato growth stage. Plastic film mulching had positive effects on soil water storage at the early stage of potato growth, while straw mulching significantly improved soil water storage at the later growth stage. The optimal water storage increasing effect was under T1, which increased soil water content by 2.8%–7.8%. Especially during the tuber formation in summer drought period, soil water content in the 0200 cm soil layer under T1 was significantly higher than under both T2 and T3. In contrast to CK, T1 increased potato yield by 10.5%–34.2% and WUE by 8.9%–29.8% (with WUE of 108.9– 134.0 kg·hm-2·mm-1), and increased commodity potato rate by 14.7%–38.8% which reached to 82.3%–92.2%. There was significant positive correlation (r = 0.836) between potato productivity and soil water consumption during the potato growth period. There were significant differences (P < 0.05) in the yield and commodity rate of potato under T1 condition, which were significantly different from those under T2 and T3. This indicated that maize-straw strip covering maintained higher soil moisture and improved plant growth and yield formation. Its application improved the efficiently of rainfall utilization to realize stable and high yields of potato. Maize-straw strip covering was a new cultivation pattern which increased crop productivity and economic benefit of potato in semiarid rain-fed regions of Northwest China.