酸胁迫下氮配比对杉木生长和砂培基质氮素的影响  

Effects of the ratios of different nitrogen forms under acid stress on growth of Chinese fir and nitrogen content in sand culture medium

作　　者：梁海燕 林智熠 杨佳玉 徐晨浩 王立冬 闫小莉 LIANG Haiyan;LIN Zhiyi;YANG Jiayu;XU Chenhao;WANG Lidong;YAN Xiaoli(College of Forestry,Fujian Agriculture and Forestry University,Fuzhou,Fujian 350002,China)

机构地区：[1]福建农林大学林学院,福建福州350002

出　　处：《森林与环境学报》2022年第6期569-575,共7页Journal of Forest and Environment

基　　金：国家自然科学基金项目“氮胁迫和异质分布环境下杉木、木荷氮吸收偏好与根系可塑性调控机制”(32171773);福建农林大学杰出青年科研人才计划项目“基于植物氮素吸收偏好性研究针阔混交树种杉木和木荷根系的觅氮策略”(KXJQ20012)。

摘　　要：为明确土壤酸化对杉木吸收铵态氮(NH^(+)_(4)-N)和硝态氮(NO^(-)_(3)-N)偏好的影响,以盆栽砂培杉木苗为研究对象,在3个pH值梯度上[P1(pH值4.5)、P2(pH值5.5)、P3(pH值6.8,对照)]分别设置3个氮形态配比[N1(CNH^(+)_(4)∶CNO^(-)_(3)=0∶10)、N2(CNH^(+)_(4)∶CNO^(-)_(3)=10∶0)、N3(CNH^(+)_(4)∶CNO^(-)_(3)=5∶5,对照)]为氮源进行盆栽试验,测定苗木生长指标和砂培基质的NH^(+)_(4)-N和NO^(-)_(3)-N含量。结果表明:在P3N3处理下,杉木苗高、地径增量和生物量均高于其他处理,分别高出14.1%~81.6%、12.7%~132.2%、26.1%~92.5%,在P1N2处理下杉木苗生长量最低。3个氮形态配比处理下,砂培基质的NH^(+)_(4)-N含量高低为P1>P2>P3,NO^(-)_(3)-N含量高低为P2>P1>P3或P1>P2>P3。在N2条件下,不同pH值处理的砂培基质NH^(+)_(4)-N含量比NO^(-)_(3)-N含量高253.3%~408.5%,且差异显著(P<0.05),而N1和N3条件下的砂培基质NO^(-)_(3)-N含量比NH^(+)_(4)-N含量高10.1%~535.7%,P1N3和P2N3处理下砂培基质的NH^(+)_(4)-N含量与NO^(-)_(3)-N含量差异显著(P<0.05),P3N3处理下则无显著差异(P>0.05)。综合以上结果表明,不同氮素形态配比下,酸胁迫会抑制杉木幼苗的生长,而无论栽培基质酸胁迫与否,氮形态配比为5∶5的处理最有利于杉木幼苗的生长和生物量积累,且在等量氮素供应下,砂培基质遗留的NO^(-)_(3)-N含量整体高于NH^(+)_(4)-N含量,表明杉木更偏向于吸收NH^(+)_(4)-N。The effects of soil acidification on the preference of ammonium nitrogen(NH^(+)_(4)-N)and nitrate nitrogen(NO^(-)_(3)-N)absorption in Chinese fir seedlings with potted sand were studied under three ratios of nitrogen forms[N1(CNH^(+)_(4)∶CNO^(-)_(3)=0∶10),N2(CNH^(+)_(4)∶CNO^(-)_(3)=10∶0),N3(CNH^(+)_(4)∶CNO^(-)_(3)=5∶5,control)]and three pH gradients[P1(pH=4.5),P2(pH=5.5),P3(pH=6.8,control)].Then,the growth index of seedlings and contents of NH^(+)_(4)-N and NO^(-)_(3)-N in sand culture medium were analyzed.The results showed that under the P3N3 treatment,the height,ground diameter increment,and biomass of Chinese fir seedlings were 14.1%-81.6%,12.7%-132.2%,and 26.1%-92.5%higher than those under the other treatments,respectively,while they were the lowest under the P1N2 treatment.Under the three nitrogen treatment ratios,the NH^(+)_(4)-N content in the sand culture medium was P1>P2>P3,and the NO^(-)_(3)-N content was P2>P1>P3 or P1>P2>P3.Under the N2 condition,the NH^(+)_(4)-N content in the sand culture medium was 253.3%-408.5%higher than the NO^(-)_(3)-N content in the three pH treatments(P<0.05),and the NO^(-)_(3)-N content in the sand culture medium was 10.1%-535.7%higher than the NH^(+)_(4)-N content under the N1 and N3 conditions(P<0.05).The NH^(+)_(4)-N and NO^(-)_(3)-N content in the sand culture medium were significantly different under P1N3 and P2N3 treatment(P<0.05),but not under P3N3 treatment(P>0.05).Under different ratios of nitrogen forms,acid stress inhibits the growth of Chinese fir seedlings.Regardless of whether the substrate was under acid stress,treatment with a ratio of 5∶5 nitrogen was most beneficial to the growth and biomass accumulation of Chinese fir seedlings.Under the same nitrogen supply,the NO^(-)_(3)-N content remaining in the sand culture medium was higher than that of NH^(+)_(4)-N,indicating that Chinese fir was more inclined to absorb NH^(+)_(4)-N.

关 键 词：酸胁迫 杉木幼苗 砂培 铵态氮 硝态氮 氮吸收偏好 

分 类 号：S714.8[农业科学—林学]