土壤养分及棉花植株干物质量对大气CO2浓度升高的响应

通过田间小区试验研究不同大气CO2浓度对土壤养分及植株干物质量的影响.结果表明:正常大气CO2浓度(CK)下施氮降低了土壤pH值,C540、C720水平下,不施氮处理土壤pH值先降后升,施氮处理土壤pH值先升后降.随大气CO2浓度增加,土壤碱解氮增加;有机碳在不同土层表现出不同变化,0～20 cm土层呈现出下降趋势,20～40 cm土层先降后升.棉花地上部干物质量随大气CO2浓度升高而增加.CK水平下施用氮肥棉花根冠比减少,C540和C720并没有得出一致性结果.

Response of soil nutrients and cotton plant dry weight to elevated atmospheric CO2 concentration

Effects of atmospheric CO2 concentration on soil nutrients and cotton plant dry weight were studied by field plot experiment. The results showed that under normal atmospheric CO2 concentration (CK), nitrogen fertilizer reduced the soil pH, under C540, C720 level, in no nitrogen treatment, the soil pH value decreased then increased, in nitrogen treatment,soil pH rose then downed. With the increase of atmospheric CO2 concentration, soil available nitrogen increased. Organic carbon showed different changes in different soil layers, 0~20 cm it showed a downward trend, in 20~40 cm it downed then rose. Cotton aboveground dry biomass increased with atmospheric CO2 concentration increasing. Under CK level nitrogen fertilizer made cotton root to shoot ratio decreased, while under C540 and C720 treatments, the results was inconsistent.