施磷对花生积累氮素来源和产量的影响

利用盆栽试验和15N示踪技术,研究了不同施磷量对花生吸收土壤氮、肥料氮、大气固氮量及比例和产量的影响,并探讨其原因,可为花生生产中科学施肥提供理论依据和技术指导。结果表明,花生根系干物重和根系活力随着施磷量的增加而增大,根瘤数和根瘤鲜重均随着施磷量的增加而增多,植株各器官含氮量和15N丰度均随着施磷量的增加而增加,成熟期各器官氮素积累量和15N积累量均表现为随着施磷量的增加而增加。花生吸收肥料氮的比例在11.34%~12.69%之间,吸收土壤氮的比例在33.95%~47.75%之间,吸收大气氮的比例在40.90%~53.36%之间,增施磷肥减小了吸收土壤氮的比例,增加了吸收肥料氮和大气氮的比例。花生氮肥利用率在34.65%~47.53%之间,氮肥土壤残留率在31.42%~36.00%之间,氮肥损失率在21.05%~29.35%之间。氮肥利用率随着施磷量的增加而增大,而氮肥土壤残留率和损失率均随着施磷量的增加而减少。综上所述,增施磷肥由于显著提高了花生根系干物重、根系活力和根瘤数及根瘤鲜重,促进了花生植株对肥料氮的吸收和对大气氮的固定,进而提高了植株体氮素含量,促进植株生长发育,最终增加产量。

Effects of Phosphorus Application on Nitrogen Accumulation Sources and Yield of Peanut

Pot experiments and 15N tracer technique were carried out respectively to study the effects of different phosphorus application on soil nitrogen uptake,fertilizer nitrogen uptake,nitrogen fixation and their proportion and yield of peanut,and to explore the reasons,the research on which may provide a theoretical basis and technical guidance for peanut production in the scientific fertilizer application.The results showed that root dry matter weight and root activity of peanut were improved with the increase of phosphorus application.Root nodule number and nodule fresh weight increased with increasing phosphorus application.Nitrogen content of different organs and 15N abundance in peanut plant were improved along with the increase of phosphorus application.In addition,both nitrogen accumulation in different organs and 15N accumulation were increased with the increase in phosphorus application during peanut mature stage.The ratio of fertilizer nitrogen,soil nitrogen and atmospheric nitrogen absorbed by peanut was respectively between 11.34%-12.69%,33.95%-47.75%,40.90%-53.36%,which showed that increasing phosphate application reduced the proportion of soil uptake,and improved the absorption ratio of fertilizer nitrogen and atmospheric nitrogen.Use efficiency,soil residual rate and loss rate of nitrogen fertilizer of peanut were between 34.65%-47.53%,31.42%-36.00%,21.05%-29.35%,respectively.Nitrogen use efficiency was improved with increasing phosphorus application,while nitrogen soil residual rate and loss rate were decreased along with increasing phosphorus application.In summary,increasing phosphorus application of peanut improved root dry matter weight,root activity,root nodule number and root nodule fresh weight,and enhanced the uptake of fertilizer nitrogen and the fixation of atmospheric nitrogen by peanut plant,thereby,improved nitrogen content of peanut plant,and promoted plant growth and development,ultimately increased peanut production.