测墒滴灌下不同氮肥水平对冬小麦光合特性及氮素转运的影响

Effects of different nitrogen on photosynthetic characteristics and nitrogen transport in winter wheat under drip irrigation

采取裂区设计,探讨测墒滴灌下不同氮肥水平对冬小麦不同生育期光合特性与氮素积累转运的变化特征.其中,氮肥为主区,设3个水平(N1:100 kg·hm^-2,N2:250 kg·hm^-2,N3:350 kg·hm^-2);滴灌为副区,设3个水平(W0:滴灌底墒水,W1:滴灌底墒水+拔节水,W2:滴灌底墒水+拔节水+开花水).结果表明:相同滴灌水平下,小麦最大光化学效率(Fv/Fm)在开花期达到最高,N2处理高于N1,N3处理;小麦叶绿素含量全生育期均表现为N2,N3显著高于N1处理;氮素总积累量、氮素籽粒积累量在N2水平下最高.N2W2处理下营养器官氮素转运量、对籽粒的贡献率最高;相同氮肥处理下,氮素总积累量、氮素籽粒积累量以W2水平最高,产量在N2W2最高,为6684.71 kg·hm^-2.综合籽粒产量、氮素积累与转运和光合特性来看,在本试验条件下,250 kg·hm^-2的施氮量、滴灌量为214.52 mm为最优的节水节氮、高产模式.

The design of the split-block was carried out to study the effects of different nitrogen on photosynthetic characteristics,nitrogen accumulation and transport during the growth period of winter wheat under drip irrigation.Nitrogen fertilizer was the main area,with 3 levels(N1:100 kg·hm^-2,N 2:250 kg·hm^-2,N 3:350 kg·hm^-2);drip irrigation was the sub-area,with 3 levels(W0:drip irrigation bottom water,W1:drip irrigation bottom water+jointing water,W2:drip irrigation bottom water+jointing water+flowering water).The results showed that the maximum photochemical efficiency(Fv/Fm)of wheat reached the highest at flowering stage,and it was higher with N2 treatment than those in N1 and N3 treatment.Under the same drip irrigation level,the chlorophyll content of wheat flag leaves showed that N2 and N were significantly higher than N1 during the whole growth period.Under N2W2 treatment,the nitrogen transport capacity of vegetative organs and the contribution rate to grain were the highest;the total nitrogen accumulation and nitrogen grain accumulation were the highest under N2 level.Under different drip irrigation treatments,total nitrogen accumulation and nitrogen grain accumulation were highest at W2 level,The highest yield is N2W2,which is 6684.71 kg·hm^-2.According to the comprehensive grain yield,nitrogen accumulation,transport and photosynthetic characteristics,the nitrogen application rate was 250 kg·hm^-2,and the drip irrigation amount was 214.52 mm,which was the optimal water-saving and nitrogen-saving model.