Effects of free-air CO2 enrichment (FACE) on soil microbial biomass under rice-wheat rotation
开放式空气二氧化碳浓度增高（FACE）对稻麦轮作土壤微生物数量的影响

The effect of CO2 enrichment on soil microbial biomass in 0-5 cm and 5-10 cm soil layers under rice-wheat rotation was studied under the conditions of routine cultivation, irrigation and fertilization. The results showed that FACE treatment could significantly increase the amount of soil bacteria in 0-5 cm and 5-10 cm soil layers during rice jointing stage and wheat wintering and ripening stages. Elevated CO2 only significantly increased the amount of soil fungi in 0-5 cm soil layer during rice ripening stage. During the whole period of rotation, the amount of soil bacteria was greater than that of soil fungi.