宁夏黄土丘陵区冬小麦农田土壤呼吸特征及影响因素分析

土壤呼吸是陆地碳循环研究的关键环节,是大气CO2的重要来源,文中以冬小麦农田为研究对象,利用ACE土壤呼吸自动监测系统,研究了冬小麦农田土壤呼吸、土壤温度、土壤水分和光合有效辐射的变化特征、相互关系以及碳释放量。结果表明:1)土壤呼吸日变化呈现"单峰型",最大值出现在13:00左右,最小值出现在夜间;2)土壤呼吸日变化表明土壤呼吸与土壤温度(0-10cm)和光合有效辐射呈显著正相关关系(P<0.01),与土壤水分的关系不确定;3)土壤呼吸季节变化表明土壤呼吸与土壤温度呈显著正相关关系(P<0.01),与土壤水分和光合有效辐射无显著相关关系;4)冬小麦农田碳释放量168gC·m-2·a-1。

Characteristics of soil respiration of winter wheat farmland and the affecting factors in the Loess hilly region of Ningxia

Soil respiration is a key link of terrestrial carbon cycle,and an important source of atmospheric CO2.Taking winter wheat farmland as research object in this study,characteristics of soil respiration,soil moisture and photosynthetically active radiation,their relationships and carbon emissions were researched by ACE(Automated CO Exchange Station) in Loess hilly region of southern Ningxia.The results suggested as follow:(1)Soil respiration showed " single peak pattern",maximum value appeared at about 13:00 and a minimum value at night.(2)Diurnal variation of soil respiration showed that soil respiration and soil temperature(0-10cm) and photosynthetic active radiation had a significant positive correlation(P < 0.01),the relation with the soil moisture was uncertaint.(3)Seasonal changes in soil respiration showed that soil respiration and soil temperature had significant correlation(P < 0.01),and the soil moisture content and photosynthetic active radiation had no significant correlation.(4) Winter wheat farmland carbon emissions was 168gC·m-2·a-1.