氮沉降对低磷胁迫下毛竹实生幼苗生长及土壤化学特性的影响

为了探究氮沉降对低磷土壤化学性状及毛竹Phyllostachys edulis实生幼苗生长的影响,以毛竹实生幼苗为材料,设计了4个不同的土壤磷水平P0(2.29 mg·kg^-1)、P1(5 mg·kg^-1)、P2(7.29 mg·kg^-1)、P3(10 mg·kg^-1),同时模拟了3个不同的氮沉降水平N0(0 kg·hm^-2·a^-1)、N1(30 kg·hm^-2·a^-1)、N2(60 kg·hm^-2·a^-1),分析氮沉降对低磷土壤的电导率、pH和N、P、K含量,以及毛竹实生幼苗生长的影响。结果表明,与对照相比,单独氮沉降(P0N2)显著提高低磷土壤电导率、有效氮含量、有效磷含量(P<0.05),分别比对照增加30.01%、75.00%和9.76%;降低低磷土壤pH、显著降低土壤速效钾含量,降幅分别为-1.52%和-33.96%(P<0.05)。氮沉降(P0N2)显著增加毛竹幼苗生物量和根冠比(P<0.05),分别比对照增加了24.59%和76.38%;氮沉降(P0N2)能抑制株高和叶面积的生长,分别比对照下降了14.04%和0.95%,但差异不显著(P>0.05)。上述结果表明,一定量的氮沉降对低磷胁迫下毛竹实生幼苗生长有有利影响。

Effect of Nitrogen Deposition on Growth of Phyllostachys edulis Seedlings and Soil Chemical Properties under Low Phosphorus Stress

On November 1st 2018,current year seeds of Phyllostachys eduli were collected from Lin’an,Zhejiang province,and were sowed in containers on November 20th of the same year.The soil was from 1m depth of Ph.eduli stand.On January 20th 2019,seedlings were transplanted in containers for experiment of different phosphorus treatments(2.29,5,7.29 and 10 mg·kg^-1)and different nitrogen deposition(0,30,60 kg/ha)a year.The treatment of 2.29 mg·kg^-1 of phosphorus and 0 nitrogen was the control.In March 2019,determinations were conducted on soil conductivity,pH,N,P,K content,and growth traits of Ph.edulis seedlings.The results showed that the treatment with 2.29 mg·kg^-1 phosphorus and 60 kg/ha nitrogen could significantly increase soil conductivity,available nitrogen and available phosphorus by 30.01%,75.00%and 9.76%of the control,and could reduce soil pH,significantly reduce available potassium soil by-1.52%and-33.96%.The treatment significantly increased the biomass and root shoot ratio of Ph.edulis seedlings by 24.59%and 76.38%,while inhibited the height and leaf area growth by 14.04%and 0.95%,but not significantly.