短期氮添加对荒漠草原土壤无机碳及土壤酸缓冲能力的影响  

Effects of Short-Term Nitrogen Addition On Soil Inorganic Carbon and Soil Acid Buffering Capacity in Desert Grasslands

作　　者：张普河 姚佳 王雪韧 李奕含 杜时荣 兴安 赵世翔 ZHANG Pu-he;YAO Jia;WANG Xue-ren;LI Yi-han;DU Shi-rong;XING An;ZHAO Shi-xiang(Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resource,College of Grassland,Resources and Environment,Inner Mongolia Agricultural University,Huhhot,Inner Mongolia 010018,China;Key Laboratory of Agricultural Ecological Security and Green Development at Universities of Inner Mongolia Autonomous Region,Huhhot,Inner Mongolia 010018,China)

机构地区：[1]内蒙古农业大学草原与资源环境学院内蒙古自治区土壤质量与养分资源重点实验室,内蒙古呼和浩特010018 [2]农业生态安全与绿色发展自治区高等学校重点实验室,内蒙古呼和浩特010018

出　　处：《草地学报》2024年第7期2081-2088,共8页Acta Agrestia Sinica

基　　金：国家重点研发计划项目,2022YFD1500901-03;国家草业技术创新中心(筹)重大创新平台建设专项,CCPTZX2023B0302资助。

摘　　要：为揭示荒漠草原土壤无机碳及土壤缓冲能力对氮添加的响应,本文采用室内模拟试验探究不同氮添加量(30 kg·ha^(-1)·a^(-1);50 kg·ha^(-1)·a^(-1))以及NH_(4)^(+)-N/NO_(3)^(-)-N比例(比例为1.63,2.5)对荒漠草原土壤无机碳和土壤酸缓冲能力的影响。研究结果表明随氮添加量以及NH_(4)^(+)-N/NO_(3)^(-)-N的增加,pH值、土壤碳酸盐及CaCO_(3)含量呈现逐渐降低的趋势,与未添加氮处理(CK)相比,外源氮添加下土壤CO_(2)-3和HCO_(3)^(-)分别下降了9.53%~51.92%和6.74%~52.21%,土壤pH值下降了0.24~0.56,土壤CaCO_(3)含量下降了6.22%~12.53%;土壤阳离子含量随外源氮添加量以及NH_(4)^(+)-N/NO_(3)^(-)-N的增加而升高,与CK相比,土壤Ca 2+和Mg 2+含量分别升高了6.30%~30.13%和20.33%~31.10%。外源氮添加降低了土壤酸中和容量且随着外源氮添加量以及NH_(4)^(+)-N/NO_(3)^(-)-N的增加而降低,不同外源氮添加处理下土壤pH值下降至8.0,7.5,7.0时土壤酸中和容量与CK相比下降了45.00%~65.21%。由此可知,外源氮添加导致土壤无机碳的溶解,降低了土壤的酸缓冲性能。The objective of this study was to elucidate the response of desert grassland soil inorganic carbon and soil buffering capacity to nitrogen addition.This paper reported an indoor simulation experiment that investigated the effects of short-term nitrogen additions on the inorganic carbon and soil acid buffering capacity of grassland soils.Two nitrogen concentration additions were set up(30 kg·ha^(-1)·a^(-1);50 kg·ha^(-1) a^(-1))along with two NH_(4)^(+)-N/NO_(3)^(-)-N ratios(ratios of 1.63 and 2.5).(1)The addition of nitrogen and the increase of NH_(4)^(+)-N/NO_(3)^(-)-N resulted in a decrease in soil carbonate content and an increase in soil cation content.Compared to no nitrogen addition treatment,the addition of exogenous nitrogen led to a decrease in soil CO_(2)-3 and HCO_(3)^(-) by 9.53%~51.92%and 6.74%~52.21%,respectively,while soil Ca 2+and Mg 2+contents increased by 6.30%~30.13%and 20.33%~31.10%;(2)The soil pH decreased overall with the increase of exogenous nitrogen addition and NH_(4)^(+)-N/NO_(3)^(-)-N.However,the difference was not significant at the beginning of the incubation period.At the end of the incubation period,the soil pH decreased by 0.24~0.56 units compared to CK;The addition of exogenous N and increasing NH_(4)^(+)-N/NO_(3)^(-)-N resulted in a decrease in soil CaCO_(3) content by 6.22%~12.53%compared to CK;(3)Exogenous nitrogen additions decreased soil acid neutralisation capacity and this effect increased with higher levels of nitrogen addition and a higher ratio of NH_(4)^(+)-N to NO_(3)^(-)-N.Soil acid neutralisation capacity decreased by 45.00%~65.21%as soil pH decreased to 8.0,7.5,and 7.0,respectively,under different exogenous nitrogen additions compared to the control.It can be seen that exogenous N additions led to the dissolution of inorganic carbon in the grassland soil,and reduced the acid buffering performance of the grassland soil.

关 键 词：荒漠草原 氮添加 土壤酸化 土壤缓冲性能 石灰性土壤 

分 类 号：S143.1[农业科学—肥料学]