开放式空气CO2浓度增高条件下旱地土壤气体CO2浓度廓线测定

设计了一套适合于FACE(free airCO2 enrichment)平台的旱地土壤气体CO2 浓度廓线测定方法 ,并将其应用于田间实验 .在江苏省无锡市郊区具有太湖地区典型水稻土的稻麦轮作农田 ,对FACE和对照麦田以及裸土 0～ 30cm土层的土壤气体CO2 浓度廓线进行了观测研究 .结果表明 ,所采用的方法满足进行旱地农田土壤气体CO2 浓度廓线研究的要求 ;在 0～ 30cm土层中 ,上层土壤气体中的CO2 向上垂直扩散要比下层土壤快 ;在作物旺盛生长期 ,大气CO2 浓度升高 2 0 0± 4 0 μmol·mol-1使 0～ 30cm土层的土壤气体CO2 浓度显著提高 14 %± 5 % (t 检验P <0 .0 0 1) .

Measurement of CO2 profiles in non-waterlogged soil in a FACE study

A method was specially designed and applied for measuring CO2 concentration of soil air over the non-waterlogged period of a rice-wheat rotation on an available area of about 1.6 m2 in a FACE (free-air CO2 enrichment) study. Based on measuring the CO2 concentration over the soil profile of 0-30 cm in depth using this method, the CO2 profile in the soils of wheat fields under elevated and ambient CO2 and the bare land under ambient CO2 was investigated and some preliminary results were obtained. Within 0-30 cm in soil depth, CO2 in the pores of the upper soil layers vertically diffused upwards much more quickly than that in the lower soil layers. During the period with active wheat growth, elevated atmospheric CO2 by 200 +/- 40 mumol.mol-1 significantly increased the CO2 concentration in soil air within 0-30 cm in depth by 14% +/- 5% (t-test, P < 0.001).