大气CO2浓度升高对水稻秸秆化学组成的影响

水稻秸秆是生物能源生产的潜在材料,大气二氧化碳(CO₂)浓度升高改变水稻秸秆的量和质,从而改变其生物能源的生产潜力.本试验水稻秸秆来自中国自由大气CO₂富集平台(FACE),选取FACE平台(试验组CO₂浓度控制在570 μmol ·mol^-1左右,比对照组高200 μmol ·mol^-1)3种水稻品种‘武运粳27’、‘Y两优900’和‘日本晴N16’,通过对秸秆化学组成进行分析,探讨CO₂浓度升高对水稻秸秆质量的影响.结果表明: 大气CO₂浓度升高显著提高了水稻秸秆C含量和C/N;增加了秸秆中非结构碳水化合物含量;CO₂浓度升高使武运粳27、Y两优900和N16秸秆中释放的总糖分别增加8.8%、6.7%和9.9%;CO₂浓度升高显著提高N16秸秆生物量,但对其他两种水稻秸秆生物量没有显著影响;N16的总糖产量在CO₂浓度升高下增加最显著,达到19.2%.表明CO₂浓度升高可以改善水稻秸秆质和量,从而提高生物燃料利用潜能.

Effects of elevated atmospheric CO2 concentration on chemical composition of rice straw

Rice straw is a potential material for bioenergy production. Elevated atmospheric carbon dioxide (CO₂) concentration changed the quantity and quality of rice straw, thus changing its bioenergy production potential. In this experiment, we collected rice straw from China Free Air CO₂ Enrichment Platform (FACE). Three rice varieties, Wuyunjing 27, Y Liangyou 900 and Nipponbare N16, were selected from the FACE platform (the CO₂ concentration in the experimental group was controlled at 570 μmol ·mol^-1, which was 200 μmol ·mol^-1 higher than the control group), the chemical composition of which was analyzed. The results showed that elevated CO₂ concentration significantly increased C content, C/N, and the content of non-structural carbohydrates in straw. Elevated CO₂ concentration significantly increased total sugar release by 8.8%, 6.7% and 9.9% in Wuyunjing 27, Y liangyou 900 and N16, respectively. Elevated CO₂ concentration significantly enhanced the biomass of N16 straw, but had no effect on the straw biomass of the other two rice varieties. The total sugar yield of N16 increased most significantly with elevated CO₂ concentration, reaching 19.2%. Our results indicated that elevated CO₂ concentration could improve the quality and quantity of rice straw, thereby increasing the utilization potential of biofuel.