灌溉水矿化度对棉田土壤呼吸速率的影响  

Effect of the salinity of irrigation water on soil respiration rate in cotton field

作　　者：李燕强 王振华[1,2,3] 叶含春 宋利兵 刘健 温越 武小荻 LI Yanqiang;WANG Zhenhua;YE Hanchun;SONG Libing;LIU Jian;WEN Yue;WU Xiaodi(College of Water Conservancy&Architectural Engineering,Shihezi University,Shihezi 832000,Xinjiang,China;Key Laboratory of Modern Water-Saving Irrigation of Xinjiang Production&Construction Group,Shihezi 832000,Xinjiang,China;Key Laboratory of Northwest Oasis Water-Saving Agriculture,Ministry of Agriculture and Rural Affairs,Shihezi 832000,Xinjiang,China)

机构地区：[1]石河子大学水利建筑工程学院,新疆石河子832000 [2]现代节水灌溉兵团重点实验室,新疆石河子832000 [3]农业农村部西北绿洲节水农业重点实验室,新疆石河子832000

出　　处：《干旱区研究》2023年第3期392-402,共11页Arid Zone Research

基　　金：国家自然科学基金项目(51869028);兵团重点领域创新团队项目(2019CB004)。

摘　　要：为探究不同灌溉水矿化度对棉田土壤呼吸速率的影响,设置了4个灌溉水矿化度,分别为0.85 g·L^(-1)(CK,当地灌溉水矿化度)、3 g·L^(-1)(S1)、5 g·L^(-1)(S2)和8 g·L^(-1)(S3),在新疆进行了膜下滴灌棉花大田试验。在棉花生育期,每月采集两次土壤呼吸速率值(R_(s)),并同时监测土壤温度(ST)、含水率(SWC)、电导率(EC)、硝态氮含量(NO_(3)^(-)-N)、铵态氮含量(NH_(4)^(+)-N),运用通径分析研究了灌溉水矿化度下土壤参数对土壤呼吸速率的影响。结果表明:微咸水灌溉(S1和S2)在一定程度上提高了土壤含水率、电导率和铵态氮含量;咸水灌溉(S3)显著增加了土壤水分和盐分,并降低了土壤硝态氮含量;灌溉水矿化度的增加会减弱土壤呼吸速率。土壤的水分和温度与呼吸速率的相关性,随灌溉水矿化度的增加而呈减弱趋势。通过运用二次函数式来表示0~10 cm的土层温度对土壤呼吸速率的响应(R^(2)=0.669,P<0.001),得出土壤呼吸速率最适宜的土壤温度为26.9℃。咸水灌溉下,含土壤温度、电导率、硝态氮含量的逐步回归方程可以解释土壤呼吸速率变化的85%。综上,利用3 g·L^(-1)的灌溉水进行膜下滴灌,能够在不显著增加土壤含盐量的基础上,降低土壤呼吸速率,减少农田碳排放量,可以为新疆微咸水资源的开发利用提供理论支撑。Four irrigation water salinity levels,namely,0.85 g·L^(-1)(CK,local irrigation water salinity),3 g·L^(-1)(S1),5g·L^(-1)(S2),and 8 g·L^(-1)(S3),were examined to explore the effects of different salinity levels on soil respiration rate in cotton fields.A cotton field experiment with drip irrigation under film was carried out in Xinjiang.During the growth period of cotton,soil respiration rate(R_s)was recorded twice a month,along with soil temperature(ST),water content,electrical conductivity(EC),nitrate nitrogen content(NO_(3)^(-)-N)and ammonium nitrogen content(NH_(4)^(+)-N).The influence of soil parameters on soil respiration rate under different salinities of irrigation water was studied by path analysis.Results showed that brackish water irrigation(S1 and S2)increased soil moisture content,EC and ammonium nitrogen content to a certain extent.Salt water irrigation(S3)significantly increased soil moisture and salinity,and decreased soil nitrate nitrogen content.The increase in the salinity of irrigation water decreased the soil respiration rate.The correlation between soil moisture and temperature and respiration rate decreased with the increase in the salinity of irrigation water.The quadratic function was used to represent the response of ST in 0-10 cm soil layer to soil respiration rate(R^(2)=0.669,P0.001).The optimal ST for soil respiration rate was 26.9℃.Under saline irrigation,the stepped-regression equation containing ST,conductivity,and nitrate nitrogen content could explain 85%of the variation of soil respiration rate.In conclusion,the use of 3 g·L^(-1)irrigation water for drip irrigation under film can reduce soil respiration rate and farmland carbon emissions without significantly increasing soil salt content.This work provides theoretical support for the development and utilization of brackish water resources in Xinjiang.

关 键 词：土壤参数 土壤呼吸 灌溉水矿化度 逐步回归 通径分析 

分 类 号：S154.1[农业科学—土壤学] S274[农业科学—农业基础科学] S562