氮磷钾缺乏对薯蔓并长期甘薯生物量累积、养分吸收与分配及其品质的影响

Effect of Fertilization on Biomass Accumulation,Nutrient Absorption/Distribution and Quality of Sweet Potatoes

田间小区试验通过不同施肥处理,研究氮磷钾配比对甘薯生物量累积、养分吸收与分配及其品质的影响。结果表明:薯蔓并长期甘薯的块根及茎叶在全素(NPK)处理下均能获得较大的生物量累积,块根中的养分含量也相对较高。与全素(NPK)相比,氮、磷、钾缺乏不同程度地影响了甘薯块根及茎叶的生物量累积,其中氮磷钾均缺乏(CK)影响最大,氮肥其次;缺氮显著影响了甘薯块根中氮的吸收,显著增加了甘薯各器官钾元素的吸收,对各器官磷的吸收影响不显著;缺磷显著降低了甘薯块根中氮和钾的含量,而缺钾增加了甘薯块根中氮的吸收,但对甘薯各器官的磷含量影响不显著。另外,氮、磷、钾缺乏降低了甘薯块根中的养分含量,作为一种淀粉类作物,淀粉含量在氮磷钾均缺乏(CK)情况下最低,其次是缺氮处理,但缺氮与缺磷和缺钾处理相比无明显差异。以上结果表明,除氮磷钾均缺乏情况,缺氮对薯蔓并长期甘薯的生长及块根中的养分含量影响最大。

Effect of varied NPK ratios on the biomass accumulation,nutrient absorption/distribution and quality of sweet potatoes were studied in a field experimentation.During the stage when the tubers and vines were allowed to grow simultaneously,fertilization with complete nutrients （N,P and K）on the sweet potato plants increased the biomasses of the tubers,shoots and leaves,as well as the nutrient contents in the tubers.Shortage on N,P and K was found to be most critical,followed by a lack of N,on the biomass accumulation.N deficiency in the soil affected the N absorption and increased the K assimilations in the tubers,but had no significant effect on the P assimilations of different organs.P deficiency significantly decreased the contents of N and K in the tubers.A deficiency in K raised the N absorption of the tuber,but did not significantly affect the P assimilations of different organs.When NPK were in a short supply,the nutrient content of the tuber was negatively affected.And,the starch content in the tubers was also lower than other deficiency conditions,while N deficiency produced the second lowest starch content in the tubers.However,the difference between N deficient sweet potatoes and P or K deficient counterparts was not significant.The results suggested that,except when N,P and K were all depleted,a shortage on N would affect most on the normal growth and nutrient contents of the sweet potatoes,if the tubers and vines were growing on the plant at the same time.