关键词: 水稻, 二氧化碳, 施肥, 产量, 元素浓度, 植酸浓度

Abstract: Elevated atmospheric carbon dioxide（CO2） concentration may alter mineral nutrition levels in grains of rice, but it is not clear whether this change is affected by fertilization. In order to understand how fertilizer level may affect rice response to elevated CO2 concentration in the atmosphere, a two-factor experiment was conducted in a Free Air CO2 Enrichment（FACE） platform located in Jiangdu, China. A japonica rice cultivar Wuyungeng 23 was grown under two levels of CO2 concentration, ambient and elevated CO2 concentration（200 μmol/mol higher than ambient, FACE）, in combination with two fertilization treatments （common and null）. At plant maturity, the yield and nutritional quality of rice grains were determined. The results showed that the yield increased by elevated CO2 concentration was not significant. Null fertilizer significantly reduced the yield （-34%）, mainly due to the substantial decrease in the number of panicles per square meter. The protein concentration in brown rice significantly decreased by 6.6% under elevated CO2 concentration, and significantly decreased by 14.3% under null fertilizer conditions. The phytate concentration in rice grains was not changed by elevated CO2 concentration, but significantly increased by 7.4% under null fertilizer conditions. Elevated CO2 concentration significantly decreased the concentration of K （-6.7%）, P （-10.5%） and S（-11.7%）. The CO2 effects on the concentrations of Ca, Mg, Cu, Zn, Mn, and B were not significant, but significantly increased the Fe concentration （+12.6%）. Without fertilizer application, the concentrations of K, P, S and Mn were significantly decreased （up to -26.1%）. Elevated CO2 concentration had no significant effect on nutrition content per unit area in rice grains （except Ca）, but null fertilizer application significantly decreased the content of protein, phytate, K, Mg, P, S, Cu, Zn, Fe, Mn and B （up to -51.3%）. The ANOVA results indicated CO2 by fertilizer interactions on the concentrations of K, Mg, P, S, Zn, Fe and Fe content. The above data showed that the yield of Wuyungeng 23 increased slightly by CO2 fumigation throughout the growing season, but the concentrations of most of elements in rice grains showed a trend of decrease （except Cu and Fe）. Without fertilizer application, grain yield and element accumulation decreased significantly, but phytate concentration increased. The interactions between CO2 and fertilizer treatment on the concentration of K, Mg, P, Fe and Fe content were significant.

Key words: rice, carbon dioxide, fertilization, yield, elemental concentration, phytate concentration