| In order to explore the effects of nitrogen application rate on flag leaf chlorophyll fluorescence characteristics and grain yield under integration of micro-sprinkler irrigation and fertilization conditions of wheat,using wheat Jimai 22 as the test material,five nitrogen treatments were set up at 0(N0),150(N1),180(N2),210(N3) and 240(N4) kg·hm-2 levels. The flag leaf maximum photochemical quantum yield of PSⅡ(Fv/Fm),the actual photochemical efficiency(ΦPSⅡ),the relative content of flag leaf chlorophyll,grain filling rate and yield under different treatments were analyzed. The results showed that,during 14 to 35 days after anthesis of wheat,there was no significant difference in flag leaf maximum photochemical quantum yield of PSⅡ(Fv/Fm) between flag leaves of N3 and N4,which was significantly higher than that under other treatments; during 0 to 35 days after anthesis,the actual photochemical efficiency(ΦPSⅡ) of N3 was the highest. When the nitrogen application amount increased to N4,no significant increase was found in ΦPSⅡ. Compared with other treatments,the relative content of flag leaf chlorophyll of N3 and N4 was significantly elevated during 14 to 28 days after anthesis,and that of N3 was significantly higher than that of N4 at 35 days after anthesis. At earlier grain filling stage,grain weight and grain filling rate were decreased with the increase of nitrogen application rate; at later filling stage,those of N3 and N4 treatments were significantly higher than those under other treatments,and no significant difference was found between N3 and N4. The highest grain yield was obtained at nitrogen application rate of 210 kg·hm-2. When nitrogen application amount was increased to 240 kg·hm-2,the grain yield was increased no longer,but the nitrogen fertilizer efficiency and the nitrogen agronomic efficiency were decreased by 14.6% and 24.0%,respectively. Under this test conditions,210 kg·hm-2 is the best nitrogen application level with both high yield and high nitrogen efficiency. |
基本信息
