关键词: 立式深旋耕, 深施肥, 马铃薯, 水分利用效率, 产量

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