关键词: 净光合速率, 蒸腾速率, 全叶马兰, 草地

Abstract: Taking the rice/wheat ozone free-air concentration enrichment (O₃-FACE) system in Jiangdu County of Jiangsu Province as a platform, this paper studied the effects of elevated atmospheric O₃ (target at 50% above ambient) on the N, P, and K concentrations in soil and wheat plant during wheat growth season. In the whole growth season of wheat, the concentrations of soil NH₄⁺-N,NO₃^--N, and available K under elevated O₃ decreased by 5.7%, 3.6% and 3.0%, respectively, while the soil available P concentration increased by 26.3% (P<0.05), compared with those under ambient O₃. Under elevated O₃, the K concentration in wheat plant at jointing stage increased by 28.4% (P<0.01), the plant N concentration at maturing stage decreased, while the P and K concentrations in wheat grain increased by 6.5% and 4.2%, respectively. Our results suggested that elevated atmospheric O₃ could promote the N and K uptake by wheat plant in its whole growth period, increase the K and P concentrations in wheat grain, but decrease the N concentration in wheat plant at maturing stage.

Key words: Net photosynthetic rate, Transpiration rate, Kelimeris integrifolia, Grassland