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根系呼吸对土壤呼吸的贡献是研究土壤碳排放和土壤碳平衡的重点和难点.本研究采用根系排除法联合运用Li-8100土壤碳通量系统测定了华北平原冬小麦-夏玉米一年两熟传统管理体系(Con.W/M)、冬小麦-夏玉米一年两熟优化管理体系(Opt.W/M)、冬小麦-夏玉米(或夏大豆)-春玉米两年三熟优化管理体系(W/M-M、W/S-M)和春玉米一年一熟优化管理体系(M)作物根区土壤呼吸和非根区土壤呼吸,以根区和非根区土壤呼吸差异除以根区土壤呼吸计算根系呼吸的贡献.结果表明,根区土壤呼吸和非根区土壤呼吸具有明显的季节变化特征,二者具有显著的拟合关系.Con.W/M和Opt.W/M处理小麦季非根区土壤呼吸可分别解释根区土壤呼吸变异的65%和87%,玉米季非根区土壤呼吸的分别解释根区土壤呼吸变异的48%和65%.W/M-M、W/S-M和M处理春玉米非根区土壤呼吸可分别解释根区土壤呼吸变异的68%、76%和58%.Con.W/M处理小麦和玉米季根系呼吸对土壤呼吸贡献分别为25.0%和29.6%,Opt.W/M处理则分别为31.1%和35.0%.不同轮作和管理措施对春玉米根系呼吸的贡献无显著影响,W/M-M、W/S-M和M处理春玉米季根系呼吸贡献分别为23.7%、24.8%和24.9%.5 cm土壤温度对根区土壤呼吸的影响程度大于非根区土壤呼吸.
The contribution of root respiration to soil respiration is the key and difficult point to study the soil carbon emission and soil carbon balance.In this study, the root exclusion method was used in combination with the Li-8100 soil carbon flux system to determine the two-year tradition of winter wheat-summer maize in the North China Plain Management System (Opt.W / M), Winter Wheat - Summer Corn (or Summer Soybean) - Spring Maize Three Years Optimization Management System / MM, W / SM) and spring maize one-year optimization management system (M) Crop root respiration and non-root soil respiration, root respiration and root-zone respiration difference divided by root-zone soil respiration Respiration. The results showed that there were significant seasonal variations in root respiration and non-root respiration, with significant fitting relationship between them.Con.W / M and Opt.W / Soil respiration explained 65% and 87% of respiration variations in the root zone, respectively, and 48% and 65% in the respiration rate in the non-root zone of maize in the spring .W / MM, W / SM and M treatments Soil respiration in the non-root zone of maize explained 68%, 76% of the variation in soil respiration in the root zone, respectively 58% .Con.W / M treatment of wheat and maize quinoa respiration on soil respiration contribution were 25.0% and 29.6%, Opt.W / M treatment were 31.1% and 35.0% .Different rotation and management measures on spring corn The contribution of root respiration had no significant effect, and the contribution of W / MM, W / SM and M treatments to spring maize root respiration was 23.7%, 24.8% and 24.9%, respectively.The effect of 5 cm soil temperature on soil respiration in root zone was greater than that of non-root Soil respiration.