氮、磷、钾肥对紫穗槐幼苗根叶化学计量特性的影响

Effects of Nitrogen,Phosphorus and Potassium Fertilization on Stoichiometric Characteristics of Root and Leaf of Amorpha fruticosa L.

探讨紫穗槐根和叶化学计量特性对养分的适应性,为豆科植物施肥和限制模式的研究提供依据,采用三因素(氮(N)、磷(P)、钾(K)),三水平(N1,N2,N3,P1,P2,P3,K1,K2,K3)的施肥处理,测定紫穗槐幼苗根和叶的碳(C)、氮、磷、钾含量,分析根和叶各元素之间的关系。结果表明,在P、K添加下,叶片比根系有更强的响应,根系对N添加有更强的反应。叶片和根N含量、根N/K和N/P随施氮水平的增加而显著增加,根P/K、叶P/K和根C/N显著降低。随着施磷量的增加,叶片N、P、K含量、根P含量、根N/K和P/K显著增加,叶N/K和叶N/P显著降低;根和叶K含量随施钾量的增加而显著增加,根N/K和P/K、叶N/K和P/K显著降低。叶P含量与根P含量、叶K含量与根K含量呈显著正相关,叶C、N含量与根C、N含量之间的关系不显著,而叶根N、P、K含量分别与相应的C/N、N/P和N/K呈显著负相关。叶和根的C/N之间的关系不显著,而叶的N/P、N/K和P/K之间的相关性显著。隶属函数分析结果表明,在紫穗槐C、N、P、K含量的累积方面,N2处理最佳。N的添加导致P对叶片和根的限制;P的添加导致N对叶片和根系的限制;K的添加并没有改变限制模式。研究结果可为紫穗槐的合理施肥和科学管理提供依据。

In order to explore the adaptability of the roots and leaves of Amorpha fruticosa L.stoichiometric characteristics to nutrients,and to provide a basis for the study of fertilization and restrict modes of leguminous plants.We used fertilization treatment with three factors(nitrogen(N),phosphorus(P),potassium(K)),and three fertilization levels(N1,N2,N3,P1,P2,P3,K1,K2,K3)to measure the carbon(C),N,P,K content of the roots and leaves of Amorpha fruticosa L.seedlings,and analyze the relationship between elements in the roots and leaves.Our results showed that the leaves had a stronger response than roots under P,K addition,and roots had a stronger response to N addition.Leaf and root N contents,root N/K and root N/P were increased significantly with increasing N addition level,root P/K,leaf P/K and root C/N decreased significantly.Leaf N,P and K content,root P content,root N/K and root P/K increased significantly,leaf N/K and leaf N/P decreased significantly with increasing P application;root and leaf K content increased significantly and root N/K,root P/K,leaf N/K and leaf P/K decreased significantly with the increasing of K application.Leaf C content,root P content,leaf K content and root K content were highly significantly positively correlated,while the relationship between leaf C,N contents and root C,N contents was not significant,while leaf and root N,P,and K contents were significantly negatively correlated with their corresponding C/N,N/P and N/K,respectively.The relationship between the ratio of carbon to nitrogen in leaf and root was insignificant,while the ratio of nitrogen to phosphorus,nitrogen to potassium and phosphorus to potassium in leaf were significantly correlated.The results of membership function analysis showed that in the accumulation of C,N,P and K contents of Amorpha fruticosa L.,N2 was the best treatment.N addition resulted in P limitations to leaves and roots;P addition resulted N limitations to leaves and roots;K addition did not changed the limitation patterns.These results can provide a good basis for rational fertilization and scientific management of Amorpha fruticosa L..