水肥条件对冬小麦旗叶光合特性及生物量的影响
Effects of water-fertilizer coupling on biomass and photosynthetic characteristics of flag leaf of winter wheat

【目的】研究水肥耦合对冬小麦旗叶光合特性及生物量的影响，建立旱地冬小麦生产的合理水肥管理模式。【方法】2011－2012年，以长旱58为供试材料，设置水分(W)和肥料(Y)2个因子，其中水分包括不灌水、低灌水量、中灌水量、高灌水量4个水平，肥料包括不施肥、低肥、中肥、高肥4个水平，共16个处理，于小麦不同生育时期测定其光合指标（净光合速率（Pn）、气孔导度（Gs）、蒸腾速率（Tr））及生物量。【结果】1）方差分析表明，水分对小麦旗叶光合特性的影响大于肥料，各施肥水平下，旗叶Pn、Gs、Tr与水分呈正相关。不论在何种水肥组合处理中，随着生育期的延长，冬小麦旗叶Pn、Gs、Tr均呈先升后降趋势，于开花期达到最大值。2）在中等施肥量水平下，小麦开花期低灌水量处理较不灌水处理、中灌水量处理较低灌水量处理Pn分别显著提高3.25%和5.01%，Gs分别显著提高10.20%和5.34%，Tr分别提高7.76%和0.15%。3）在土壤水分较充足时，小麦旗叶Pn、Gs、Tr随施肥水平的增加而提高，小麦开花期Pn在中等灌水量水平下，低施肥量处理较不施肥处理、中施肥量处理较低施肥量处理Pn分别显著提高2.45%和3.19%, Gs分别显著提高3.27%和4.23%，Tr分别显著提高4.26%和6.86%。4)同一水分条件下，灌浆期和成熟期生物量均随施肥量的增加先增后减，最高生物量出现在中等肥力水平（Y2）时；返青期和孕穗期，生物量随施肥量的增加逐渐增大。各灌水条件下，开花期生物量随施肥量的增加而变化趋势不同。【结论】高水（100 mm）中肥（N、P2O5、K2O用量分别为278.55，163.20，322.80 kg/hm2）组合的小麦旗叶光合特性较为优良。
【Objective】The effects of water and fertilizer coupling on biomass and photosynthetic characteristics of flag leaf of winter wheat were studied to establish a suitable water-fertilizer management mode for winter wheat in semiarid areas.【Method】In 2011-2012,a pool-culturing experiment with Changhan 58 as experimental material was conducted,which considered two factors:irrigation (W) and fertilizer (Y).There were 4 levels for irrigation (no irrigation,low irrigation,medium irrigation,and high irrigation) and fertilizer (no fertilizer,low fertilizer,medium fertilizer and high fertilizer).Biomass and photosynthetic indicators (Pn,Gs,and Tr) of 16 different water and fertilizer coupling treatments were compared and analyzed at different growth stages.【Result】1） Variance analysis showed that the effects of water on photosynthetic characteristics of the flag leaf were greater than that of fertilizers.Under different fertilizer treatments,flag leaf photosynthetic characteristics and water were positively correlated (P<0.05).Under every water-fertilizer coupling treatment,Pn,Gs and Tr of flag leaf increased first and decreased afterwards with the highest values at flowering stage.2） In flowering period,under the medium fertilizer rate,Pn,Gs and Tr of low irrigation treatment were 3.25% (P<0.05),10.20% (P<0.05),and 7.76% (P<0.05) higher than that in no irrigation treatment,and Pn,Gs and Tr of medium irrigation treatment were 5.01% (P<0.05),5.34% (P<0.05),and 0.15% higher than that in low irrigation treatment,respectively.3） With sufficient soil moisture,Pn,Gs,Tr of winter wheat flag leaf increased with the increase of fertilizing rate.In flowering period under medium irrigation level,Pn,Gs and Tr of low fertilizer treatment were 2.45%,3.27% (P<0.05) and 4.26% (P<0.05) higher than that in no fertilizer