膜荚黄芪干物质累积及氮、磷、钾吸收规律的研究

目的：研究膜荚黄芪干物质累积及氮、磷、钾吸收特性。方法：通过田间试验和采样分析研究了黄芪不同生长期植株的生长量及对氮、磷、钾的吸收量。结果：黄芪出苗后100～163 d植株干物质积累量占总积累量的88.22%。黄芪各器官氮、磷、钾的含量表现为茎叶＞根系,黄芪茎叶和根系中的氮、磷、钾养分的吸收量为氮＞钾＞磷。在黄芪整个生育期,黄芪对氮的积累强度最大,钾次之,磷最小。黄芪营养旺盛生长后期,氮、磷、钾的累积强度降低,至收获期,根系氮、钾的累积强度有所升高,磷的累积强度基本稳定。黄芪根系对氮、磷、钾相对吸收强度最大值比茎叶出现的早,茎叶对氮、磷、钾的吸收强度最大时期在出苗后100～132 d,氮、磷、钾积累强度曲线出现一个高峰。结论：黄芪出苗后100～163 d是黄芪植株干物质积累量最快的时期。出苗后100～132 d是黄芪茎叶氮、磷、钾吸收强度最大时期,且氮吸收高峰期早于钾、磷；这时每天形成1 kg的干物质所需要的养分量最多,是黄芪的氮、磷、钾营养临界期；每生产100 kg黄芪需要从土壤和肥料中吸收2.32 kg 氮；0.323 kg P₂O₅；1.62 kg K₂O。

Study on accumulation of dry matter and aborption of N, P and K of Astragalus membranaceus

Objective:To study Astragalus membranaceus absorption characteristic of nitrogen,phosphorus and potassium at different growth stages.Method:Through the field experiment and the sampling analysis,the absorbing capacity of nitrogen,phosphorus and potassium as well as the growth of plant at different growth stages in A.membranaceus were analyzed.Result:The dry matter accumulation reached 88.22% of the total accumulation in 100-163 days after seedling emergence,The content of N, P,K in the stem was higher than that in the root system.Nitrogen,phosphorus and potassium absorbing capacity in the stem,the leaf and the root system's was N>K>P.In the whole growth!period,nitrogen accumulation reached the highest,and followed with the accumulation of potassium,and the accumulation of phosphorus was the lowest.In the last phase of the exuberant growth period,the accumulation intensity of nitrogen,phosphorus and potassium reduced.During the harvesting time,the accumulation intensity of nitrogen and potassium increased,and the accumulation intensity of phosphorus remained stable.Conclusion:The dry matter accumulation reached the maximum in 100-163 days after seedling emergence.The absorption strength of nitrogen,phosphorus and potassium in aerial part reached the maximum in 100-132 days after seeding emergence,the maximum absorption comes earlier than that of phosphorus and potassium,at that time the needs of nutrients reach the highest.For producing of 100 kg A.membranaceus 2.32 kg N,0.323 kg P2O5,1.62 kg K2O are needed to be absorbed from soil and fertilizer.