氮磷钾肥配施对宁南旱区马铃薯产量和水分利用效率的影响

针对宁南旱地马铃薯水分利用效率较低的问题，采用养分丰缺指标法，研究氮、磷、钾肥缺素配施条件下土壤剖面水分动态分布、马铃薯产量构成、产量以及水分利用效率变化特征。以‘庄薯3 号’（一级种薯）为材料，在宁夏南部旱地上研究CK、NP、NP、PK、NPK施肥处理对土壤剖面储水动态、马铃薯产量及水分利用效率的影响。结果表明：2012—2013 年马铃薯生育后期施肥处理土壤剖面含水量均低于对照，NK、NPK处理提高了盛花期—块茎生长期1 m土体储水量，同时提高了马铃薯耗水量，NK处理提高了1.1%~1.8%，NPK提高了3.2%和4.4%。与对照相比，NK和NPK处理提高了结薯个数和单株产量，进而提高马铃薯产量，其中NPK处理最高，增产率为11.7%和15.9%，其次为NK处理；施肥处理较CK水分利用效率增幅为2.9%~13.2%、2.8%~8.0%，均以NPK处理最高，其次为NK处理。宁南旱地马铃薯缺氮和缺钾对马铃薯产量和水分利用效率影响较大，氮钾以及氮磷钾肥合理配施，可提高马铃薯对土壤水分的利用能力实现马铃薯增产和水分增效。

The Effect of Different NPK Fertilizations on Yield and Water Use Efficiency of Potato in Semi-arid Areas of Southern Ningxia

The water use efficiency of dryland was low in southern Ningxia. The experiments were implemented with nutrients abundance and deficiency index method (different combinations of nitrogen, phosphorus and potassium) to study the soil water dynamic distribution of potato‘( Zhuang No.3’), potato yield components, yield and variation characteristics of water use efficiency. The effect of different fertilization treatments such as CK, NP, NP, PK and NPK on soil cross-section dynamic water storage, potato yield and water use efficiency was discussed. The results showed that in 2011 and 2013, soil profile moisture contents of fertilization treatments were all lower than that of the control in the late growth period, and NK and NPK treatment improved 1 m soil water content in the tuber growth period (by 1.1% and 3.2% respectively), and increased the potato water consumption (by 1.8% and 4.4% respectively). Compared with the control, NK and NPK treatment raised potato yield by increasing the number of tubers and grain yield per plant (NPK treatment had the highest yield, the increase rate of the number of tubers was 11.7% and that of the grain yield per plant was 15.9%, and the yield of NK treatment was the second). Compared with the control, water use efficiency of NPK treatment increased by 2.9% to 13.2%, while that of NK treatment increased by 2.8% to 8.0%. Potato yield and water use efficiency in dryland of southern Ningxia were significantly affected by the lack of nitrogen and potassium. Nitrogen cooperated with potassium fertilizer and the reasonable application of NPK fertilizer could improve the ability of soil water utilization in potato, therefore, to increase the potato yield and water use efficiency.