Abstract: Investigation on the effect of free air CO₂ enrichment (FACE) on biomass accumulation and distribution in different parts of rice plant treated with 200 μmol·mol^-1 CO₂ elevation under field condition showed that the dry matter accumulated from transplanting to 20th day after heading and the total biomass increased significantly, while the dry mater accumulated from²0th day after heading to maturity was significantly depressed under FACEtreatment. The enhancement of both leaf area index (LAI) and net assimilation rate (NAR) under FACE treatment resulted in the increase of dry matter accumulated from transplanting to heading, while the dominant reason for the increase of dry matter accumulated during 20 days after heading was the slowed decline of LAI. The decline of dry matter accumulated from²0th day to maturity was mainly caused by the decrease of NAR. The percentage of dry matter distributed in stem and sheath increased under FACEtreatment, while that in leaf decreased, and that in panicle showed no significant change. The content (%) and amount of soluble sugar and starch in stem and sheath at heading was significantly elevated under FACE.The grain yield of rice under FACEtreatment could be significantly improved by raising biomass.

Key words: Rice, Free air CO₂ enrichment, Biomass accumulation and partition, Soluble carbohydrates, Leaf area index, Net assimilation rate, strip covering, plastic film mulching, winter wheat., soil temperature, semiarid area, maize straw