摘要
研究土壤微量元素含量对CO_(2)摩尔分数和温度升高的响应,可为气候变化背景下农田土壤健康质量评价提供科学依据。以谷子(Setaria italica)为试验材料,设置3种气候模拟情景,即对照(400μmol/mol CO_(2)摩尔分数,22℃大气温度)、仅CO_(2)摩尔分数升高(700μmol/mol CO_(2)摩尔分数,22℃大气温度)和CO_(2)摩尔分数和温度双升高(700μmol/mol CO_(2)摩尔分数,26℃大气温度)和2种水分条件,即充分供水(70%田间持水量)和轻度干旱(50%田间持水量),研究谷子农田土壤微量元素对CO_(2)摩尔分数升高和增温的响应。结果表明:1)仅CO_(2)摩尔分数升高较对照处理增加土壤有效态微量元素含量,其中,在轻度干旱胁迫下土壤有效铜和锌含量分别显著增加20.4%和107.4%(P<0.05),在充分供水条件下二者分别显著增加18.6%和133.4%(P<0.05);2)CO_(2)摩尔分数和温度双升高较对照处理增加土壤有效态锰、铜和锌含量,但降低土壤有效铁含量;其中,充分供水条件下土壤有效铜和锌含量分别显著增加19.4%和109.3%(P<0.05),轻度干旱条件下土壤有效锰、铜和锌含量分别显著增加14.4%、14.5%和118.3%(P<0.05);3)充分供水条件下土壤有效锌含量和谷子地下生物量呈显著负相关,而其与土壤有机质含量呈显著正相关;轻度干旱条件下土壤有效锰与谷子地上生物量呈显著负相关。总之,CO_(2)摩尔分数升高在不同程度上增加土壤有效态微量元素含量,但在CO_(2)摩尔分数升高的基础上增温则使土壤有效态微量元素含量的增幅减小;与土壤有效铁和有效锰相比,土壤有效铜和有效锌对CO_(2)摩尔分数升高和增温的响应更为敏感。
[Background]The fifth IPCC assessment report pointed out that the atmospheric CO_(2)concentration would exceed 700μmol/mol at the end of the 21st century,and the global mean surface temperature would rise by 0.3℃-4.8℃on the current basis.Climate change induces multiple stresses on plant growth and soil health quality.It is well known that soil microelements are crucial indicators for plant growth and soil health quality.Previous studies generally focused on the isolated effect of elevated CO_(2)concentration and temperature on soil microelement contents.Therefore,clarifying the coupling effects of elevated CO_(2)and temperature on soil microelements is crucial for the evaluation of soil health quality under the climate change background.[Methods]A pot experiment was conducted in artificial climate chambers to investigate the coupling effects of elevated CO_(2)and temperature on 4 kinds of soil microelement availability(Fe,Mn,Cu and Zn).The experimental treatments included 3 climate scenarios,i.e.,the controlled experiment(400μmol/mol CO_(2)and 22℃,CK),elevated CO_(2)(700μmol/mol CO_(2)and 22℃,EC),both elevated CO_(2)and temperature(700μmol/mol CO_(2)and 26℃,EC+ET),each climate scenario covered two water conditions,i.e.,sufficient water supply(70%of field capacity)and light water stress(50%of field capacity).The total and available contents of soil microelements were measured at maturity stage of millet.[Results]1)Compared with CK,only elevated CO_(2)treatment increased soil available microelement contents under the 2 water conditions.Under the light water stress condition,elevated CO_(2)significantly increased the contents of soil available Cu and Zn by 20.4%and 107.4%,respectively(P<0.05);and under the sufficient water supply condition,elevated CO_(2)concentration significantly increased 18.6%and 133.4%of soil available Cu and Zn contents,respectively(P<0.05).2)Compared with CK,both elevated CO_(2)and temperature increased soil available Mn,Cu and Zn contents under the two water conditions,while it reduced the soil available Fe content.Under the sufficient water supply condition,soil available Cu and Zn contents significantly increased by 19.4%and 109.3%,respectively(P<0.05).Under the light water stress condition,soil available Mn,Cu and Zn contents significantly increased by 14.4%,14.5%and 118.3%,respectively(P<0.05).3)Under the sufficient water supply condition,soil available Zn content had a significantly negative correlation with millet belowground biomass,while it had a significantly positive correlation with soil organic matter content;under the light water stress condition,soil available Mn content showed a significant decreasing trend with the increase of millet aboveground biomass.[Conclusions]Elevated CO_(2)promotes the accumulation of soil available microelement contents,but this promotion is weakened when the temperature increases simultaneously.Compared with soil available Fe and Mn contents,soil available Cu and Zn contents are more sensitive to elevated CO_(2)and temperature.These results may enhance the understandings on the impacts of climate change on soil microelement availability.
作者
赵苗苗
郑粉莉
王婧
王雪松
焦健宇
魏晗梅
ZHAO Miaomiao;ZHENG Fenli;WANG Jing;WANG Xuesong;JIAO Jianyu;WEI Hanmei(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Northwest A&F University, Yangling, Shaanxi, 712100, China;Institute of Soil and Water Conservation, CAS & MWR, Yangling, Shaanxi, 712100, China)
出处
《中国水土保持科学》
CSCD
北大核心
2022年第3期53-61,共9页
Science of Soil and Water Conservation
基金
中国科学院国际合作局国际伙伴计划项目“气候变化对中国黄河中游和塞尔维亚萨瓦河流域农业水土环境影响评估及适应对策”(161461KYSB20170013)。
作者简介
第一作者:赵苗苗(1998—),女,硕士研究生。主要研究方向:气候变化与土壤生态。E-mail:zhmm@nwafu.edu.cn;通信作者:郑粉莉(1960—),女,博士,研究员。主要研究方向:土壤侵蚀过程,预报和环境效应评价。E-mail:flzh@ms.iswc.ac.cn。
