砾石长期覆盖对土壤呼吸的影响  

Long-term effects of Gravel-Sand mulch on diurnal variation of soil respiration in Semi-arid Loess Plateau,China

作　　者：赵成政 王亚军 谢忠奎 张玉宝 郭志鸿 邱阳 华翠平 周丽靖 Zhao Chengzheng;Wang Yajun;Xie Zhongkui;Zhang Yubao;Guo Zhihong;Qiu Yang;Hua Cuiping;Zhou Lijing(Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院西北生态环境资源研究院,甘肃兰州730000 [2]中国科学院大学,北京100049

出　　处：《中国沙漠》2020年第2期232-239,共8页Journal of Desert Research

基　　金：国家重点研发计划项目(2016YFC0501403-3).

摘　　要：砾石覆盖是西北黄土高原地区的传统保护性耕作技术,具有明显的蓄水、保墒、增温、压碱和保持地力作用。研究砾石覆盖农田系统中的土壤呼吸,有助于了解地面覆盖条件对CO2通量的影响和土壤健康状况。利用LI6400土壤呼吸系统对甘肃皋兰长期砾石覆盖农田(12年)不同覆盖厚度下的土壤呼吸进行了原位监测,并对环境因子与土壤呼吸的日变化相关性进行了分析。结果表明:(1)土壤呼吸的日变化与温度的变化一致,呈单峰型,砾石覆盖后土壤呼吸峰值出现在16:00-17:00,明显滞后于裸地出现的峰值时间(14:00-15:00),且峰值随着覆盖厚度的增加而减小;(2)土壤表层(0~10 cm)温度与土壤呼吸呈极显著幂函数关系(P<0.01),砾石覆盖降低了土壤呼吸的温度敏感性指数(Q10),覆盖后两次监测中Q10为1.78~2.87(2017年)和1.70~1.96(2018年);(3)砾石覆盖后提高了夜间土壤呼吸,导致土壤呼吸的日累积碳排放量显著提高,随着覆盖厚度的增加而降低,覆盖处理中厚度为11 cm最小的碳排放量两次测量分别为2.00 g·m-2和0.90 g·m-2,比裸地分别增加了15%和18%;(4)土壤特征因子中,土壤水分、pH与土壤呼吸累积碳排放量呈正相关,有机质、碱解氮、速效磷、电导率与土壤呼吸累积碳排放量呈负相关。Gravel-sand mulch is a protective farming technique with a history of 300 years in the Loess Plateau of the Northwest.It has the effects of water storage,water retention,temperature increasing,alkali pressing and soil retention.As the mulch area increases year by year,studying the soil respiration in the gravel-sand mulch farmland system helps to understand the impact of ground mulch conditions on CO2 flux and soil health.However,little is known about the changes in soil respiration and the main influencing factors under the mulch.In Gansu province,the soil respiration of long-term gravel-sand mulched farmland(12 years)was measured by using the LI6400 soil respiration system.The relationship between the environmental factors,the physical and chemical properties of the soil and the diurnal variation of the soil respiration was analyzed.The results showed that:(1)The diurnal variation of soil respiration was consistent with the change of temperature,and it was unimodal,and the peak of the soil respiration after gravel mulched was(16:00-17:00),which was obviously lagging behind the bare ground(14:00-15:00),and the peak value decreases with the increase of the mulch thickness;(2)the temperature of the soil surface layer(in the depth of 10 cm)is a significant power function relation with the soil respiration(P<0.01),and the gravel mulch reduces the temperature sensitivity index(Q10)of the soil respiration,and the mulched Q10 is 1.78-2.87 and 1.70-1.96;(3)after the gravel mulched,the soil respiration at night is improved,the daily accumulated carbon emission of the soil respiration is obviously improved,and the carbon emission of the thickness of 11 cm(GM11)in the mulch treatment is 2.00 g·m-2 and 0.90 g·m-2,respectively,as the mulch thickness increases,15%and 18%,respectively,compared with the bare ground(CK).(4)The soil water,pH and soil respiration accumulated carbon emission were positively correlated with the soil characteristic factors,and the organic matter,the alkali-hydrolyzable nitrogen,the available phosph

关 键 词：砾石覆盖 土壤呼吸 温度敏感性指数 

分 类 号：S154.1[农业科学—土壤学]