【摘要】 从高产施肥的角度,研究了不同氮、磷、钾肥用量对旱作春玉米穗位叶净光合速率(Pn)、气孔导度(Cond)、胞间CO2浓度(Ci)、蒸腾速率(Tr)等光合指标的影响。结果表明:各施肥条件下,穗位叶全展后期Pn、Cond随玉米生育期的推进呈现逐渐下降的变化趋势,而Ci、Tr则呈先降低后增加的趋势。不同氮、磷、钾用量对穗位叶4个光合指标的影响也较明显:穗位叶全展前期,Pn、Cond、Ci和Tr均随施氮、磷水平的提高而增加,而随钾肥水平的提高,Cond、Ci、Tr均降低;而后期,表现出适宜氮、磷、钾施肥量有提高光合能力的优势,即氮、磷、钾养分缺乏或过量均会使后期光合能力降低。可见,适宜的氮、磷、钾用量(N240kg.hm-2、P2O5150kg·hm-2、K2O75kg·hm-2)可保持春玉米穗位叶净光合速率、气孔导度、胞间CO2浓度、蒸腾速率等光合指标的适宜状态,并能保持较长的高光合持续期,有效地提高玉米的光合作用,增加产量。更多还原

【Abstract】 From the viewpoint of high-yield application of fertilizers,we studied the effect of different nitrogen,phosphorus and postassium contents on photosynthesis rate(Pn),stomatal conductance(Cond),intercellular CO2 concentrations(Ci),transpiration rate(Tr) in ear-leaf of spring maize under drought conditions.The results indicated that under different fertilizer applications,the photosynthesis rate,stomatal conductance had a similar downtrend with growth stage;The intercellular CO2 concentrations and the transpiration rate increased at first and then decreased;different nitrogen,phosphorus and potassium contents affected photosynthesis.Pn,Cond,Ci and Tr in ear leaves increased with application of nitrogen,phosphorus raising prophase.With the postassium increase,Cond,Ci and Tr lowered.However,the optimal proportions of nitrogen,phosphorus and potash fertilizer contents could raise the photosynthesis at late stage.The photosynthesis would decline if the nitrogen,phosphorus and postassium contents were too high or low.The suitable nitrogen,phosphorus and postassium contents(N 240 kg.hm-2,P2O5 150 kg·hm-2,K2O 75 kg·hm-2)could keep the photosynthesis rate,stomatal conductance,intercellular CO2 and transpiration rate at high levels and result in high yields.更多还原