大气CO_2浓度升高对稻田土壤Ca、Mg迁移的中长期效应  

Medium-long Term Effects of Elevated Atmospheric CO_2 on Transposition of Ca and Mg in a Rice Paddy Field

作　　者：宋亭洁[1,2] 朱建国[1] 孙会峰[3] 刘钢[1] 唐昊冶[1] 曾青[1] 

机构地区：[1]土壤与农业可持续发展国家重点实验室(中国科学院南京土壤研究所),南京210008 [2]中国科学院大学,北京100049 [3]上海市农业科学院生态环境保护研究所,上海201403

出　　处：《土壤》2013年第5期905-909,共5页Soils

基　　金：科技部国际科技合作与交流项目(2010DFA22770);国家自然科学基金国际(地区)合作与交流项目(31261140364);国家自然科学基金项目(41271310)资助

摘　　要：为了进一步认识稻田土壤中Ca、Mg元素生物地球化学循环对大气CO2浓度升高的响应,本实验利用中国稻麦轮作FACE(free air carbon-dioxide enrichment)试验平台,通过观测稻季不同生育期不同深度(30、60和90 cm)土壤溶液中的Ca2+、Mg2+浓度,研究大气CO2浓度升高对土壤Ca、Mg淋移的中长时期(第9年)影响。研究结果表明,随着土壤深度的增加,土壤溶液中的Ca2+浓度呈降低趋势,Mg2+浓度呈增加趋势;随着生育期的推进,呈现先增加后减小的趋势,并在抽穗期达到最大值。大气CO2浓度升高略微降低30、60 cm处土壤溶液的Ca2+浓度,增加90 cm处Ca2+浓度(6.7%)。稻田不同深度土壤溶液中Mg2+浓度对大气CO2浓度升高的响应有所不同,且在60 cm处有较强的正响应(12.1%)。研究明确高浓度CO2有加剧Ca2+、Mg2+向下淋溶损失的趋势,耕层土壤有机物料输入增多、3HCO-浓度增加、pH下降等是主要原因。大气CO2浓度升高对农田生态系统土壤Ca、Mg元素循环的长期影响值得进一步关注。To further investigate the response of biogeochemical cycle of Ca and Mg to atmospheric CO2 enrichment,a study associated with the medium-long term effects of elevated CO2 on transposition of Ca and Mg at three soil depths （30,60,and 90 cm） in different developmental stages was carried out on China rice-wheat rotation FACE （Free Air Carbon-dioxide Enrichment） experimental platform in the rice growing season.The results showed that with the increment in the soil depth,the Ca2＋ concentration in soil solution showed a trend of decrease,and the Mg2＋ concentration was increasing; whereas they increased at first and decreased then,and peaked at heading stage.Atmospheric CO2 enrichment slightly decreased the Ca2＋ concentration in the soil solution at 30 and 60 cm,but enhanced it at 90 cm （6.7％）.It was detected that the responses of Mg2＋ concentration in the soil solution to elevated CO2 differed with the soil depth,and a stronger positive response was found at 60 cm （12.1％）.This study indicated that elevated CO2 tends to intensify the leaching loss of Ca2＋ and Mg2＋,the increase in organic materials input and HCO3-concentration,and decrease in pH in the plow layer are the main causes.The long term effects of elevated CO2 on Ca and Mg cycle in the soil under agricultural ecosystems deserve a further attention to pay.

关 键 词：CO2浓度升高 稻田土壤溶液 CA Mg 淋溶 

分 类 号：S153.5[农业科学—土壤学] S151.9[农业科学—农业基础科学]