Abstract: The deep fertilization can improve nutrient utilization efficiency and reduce the risk of environmental pollution, and vertically rotary tillage (VRT) provides soil condition for deep fertilization. In this study the potato with plastic mulching and VRT was used as material, three treatments of fertilization depth were set, including no fertilization (VP), 15 cm of fertilization depth (VPF), 30 cm of fertilization depth (VPD). The soil water content, SPAD value, dry matter weight and tuber yield of potato were measured. The results showed that: VPD increased the SPAD value in leaf at later stage, especially  increased by 0.2%~13.8% at the starch accumulation stage, and the soil water contents in 0—200 cm soils was significantly decreased by 13.4%~39.0%. VPD could increase the number of potato, the weight of tuber per plant, the proportion of medium and large potatoes and the commodity rate, respectively. Compared with VPF and VP, the water consumption of VPD was decreased by 36.5%~43.3% before flowering, but increased by 49.8%~58.7% after flowering in 2018. The yields of VPD were increased by 7.7%~569%, and the water use efficiencies (WUE) of VPD and VPD were increased by 12.2%~28.2% and 16.8%~271%, respectively. Therefore, under the VRT condition in the semi-arid area of northwest China, the deep fertilization could increase the yield and WUE of potato, which should be beneficial to improve crop yield and utilization efficient of resources.

Key words: vertically rotary tillage, deep fertilization, potato, water use efficiency, yield

摘要： 肥料深施可提高养分利用效率、降低环境污染风险，立式深旋耕为肥料深施提供了土壤条件。在半干旱雨养农业区，以立式深旋耕全膜覆盖马铃薯为研究对象，设置不施肥（VP）、15 cm处施肥（VPF）和30 cm处施肥（VPD）3个处理，测定了土壤含水量、马铃薯叶片SPAD值、干物质量、产量等指标。结果表明：VPD提高了马铃薯生育后期的叶片SPAD值，尤其在淀粉积累期较VPF增加了0.2%~13.8%；同时降低了0—200 cm的土壤贮水量，较VPF下降13.4%~39.0%，差异显著。VPD处理的马铃薯花前耗水量较VPF和VP下降，而花后耗水量增加，其中2018年的花前耗水量较VP和VPF降低了36.5%~43.3%；花后增加49.8%~58.7%。VPD提高了马铃薯单株结薯数、单株块茎重、大中薯所占比例，提高了商品率。VPD的块茎产量较VPF和VP增加7.7%~56.9%；VPF和VPD的水分利用效率无显著差异，但较VP分别提高12.2%~28.2%和16.8%~27.1%。因此，在西北半干旱区立式深旋耕条件下，肥料深施可提高马铃薯的产量和水分利用效率，能够实现作物增产和资源高效利用的目标。

关键词: 立式深旋耕, 深施肥, 马铃薯, 水分利用效率, 产量