施钾对花生积累氮素来源和产量的影响

EFFECTS OF POTASSIUM APPLICATION ON THE ACCUMULATED NITROGEN SOURCE AND YIELD OF PEANUT

利用盆栽试验和15N示踪技术,研究了不同施钾量对花生吸收土壤氮、肥料氮、根瘤固氮量及比例和产量的影响。结果表明,不同施钾处理花生氮素均主要积累在籽仁中,但随着施钾量的增大,花生各器官中茎的含氮量增加幅度最大,果壳的含氮量增加幅度最小。适当增施钾肥可以提高各器官含氮量和15N丰度、氮素和15N积累量,促进花生植株对3种氮源的吸收利用,尤其对籽仁生物量(经济产量)的影响最大。吸收土壤氮的比例在38.29%～45.10%之间,吸收肥料氮的比例在12.37%～13.40%之间,吸收大气氮的比例在42.53%～48.31%之间。适量增施钾肥提高了吸收肥料氮和根瘤固氮的比例,降低了吸收土壤氮的比例,提高了肥料氮的利用率,但过量施钾效果降低。

Pot experiments and were carried out respectively to study the effects of different potassium application on soil nitrogen uptake,fertilizer nitrogen uptake,nodule nitrogen fixation and their proportion and yield of peanut（Arachis Hypogaea L.） by 15N tracer technique,and explore the reasons,which may provide a theoretical basis and technical guidance for peanut production in the scientific fertilizer application.Results showed that nitrogen in peanut all mainly accumulated in the kernel for different treatments of potassium fertilizer application.However,with increasing of potassium application,the increasing extent of nitrogen content of stems was the biggest during all the peanut organs,with nut shells the smallest.Properly increasing the amount of potassium can improve nitrogen content,15N abundance,nitrogen and 15N accumulation of every organ,and promote absorption and utilization three nitrogen-source especially with the most effect for the kernel biomass（economic output）.The ratio of fertilizer nitrogen,soil nitrogen and atmospheric nitrogen absorbed by peanut was respectively between 12.37%-13.10%,38.29%-45.10%,and 42.53%-48.31% respectively.Properly increasing potassium fertilizer application improved the absorption ratio of fertilizer nitrogen and nodule nitrogen fixation,reduced the proportion of soil uptake and enhanced fertilizer nitrogen use efficiency.However,the influences of excessive application of potassium fertilizer decreased.