高产施肥条件下玉米的光合特性研究

采用田间试验与生化分析相结合的方法，研究了不同氮、磷、钾肥施用量对春玉米产量及叶片光合特性的影响。研究结果表明：当N、P2O5、K2O用量分别为240、150和240kg／hm^2时，玉米的产量、叶绿素含量和叶面积指数、叶片的光合速率、气孔导度和胞间CO2浓度等光合特性均处于最高水平，缺乏或过量的氮、磷、钾供应均不利于春玉米产量和光合性能的提高。由此得出以下结论：适宜的氮、磷、钾肥用量能够在春玉米生育前期提高其叶面积指数和光合色素含量以及光合速率等光合特性，在生育后期能延缓叶面积指数的衰退和光舍色素含量的降低，使得叶片具有较高的光合性能，从而促进了高产的形成。

Studies on Photosynthetic Characteristics of Maize Leaves with High-yield Fertilization

The method of field trials experiments combined with biochemical examination were adopted to study the effects of different N,P and K fertilization on the yield and some photosynthetic characteristics of spring maize leaves.The results showed when N,P and K application amount were 240,150 and 240 kg/ha,the yield and the photosynthetic characteristics such as Chlorophyll content and leaf area index(LAI),Photosynthetic rate(Pn),Stomatal conductance(Gs) and Intercellular CO2 concentration(Ci) took on the highest level.The results also showed that deficient or superfluous N,P and K application could decrease the photosynthetic characteristics of maize leaves.So the conclusion as follow: Rational N,P and K application could accelerate the photosynthetic characteristics such as LAI,Chlorophyll content and Pn of spring maize at earlier stages,could slow down the recession LAI and Chlorophyll content,therefore stimulate maize yield.