施氮量对高产春大豆光合特性及产量的影响

Effects of Nitrogen Application on Photosynthetic Characteristics and Yield of High-yield Spring Soybean

为揭示不同施氮量对滴灌条件下高产春大豆不同冠层光合特性的影响规律,在大田条件下,研究4种施氮量(0、75、150、225 kg/hm^2)对高产春大豆植株形态特征及不同冠层叶片叶绿素含量、光合参数的影响。结果表明:增施氮肥显著提高大豆植株中上部节间长度、叶柄长度和叶形指数;提高大豆不同冠层叶片叶绿素含量,施氮处理使植株后期中上部叶片叶绿素含量的下降幅度较N0处理减缓1.31%~4.44%;提高不同生育时期不同冠层叶片的净光合速率(Pn),减缓了中后期不同冠层净光合速率的下降幅度;施氮增加产量,以N150产量较高,为4889.62 kg/hm^2,氮肥农学利用效率3.58 kg/kg。

To reveal the effect of different nitrogen application rates on photosynthetic characteristics of different canopy layers of high-yield spring soybean under drip irrigation,under field condition,the effects of 4 nitrogen application levels(0,75,150 and 225 kg/hm^2)on the plant morphological characteristics,the chlorophyll content and photosynthetic parameters of different canopy leaves of high yield spring soybean were studied.The results showed that the increase of nitrogen fertilizer significantly increased the internode length,petiole length and leaf shape index of soybean plants;it also increased the chlorophyll content of different canopy leaves of soybean;the decrease of chlorophyll content in the middle and upper leaves of the plant treated with nitrogen fertilizer was 1.31%-4.44%lower than that of the N0 treatment.The net photosynthetic rate(Pn)of different canopy leaves at different growth stages increased,which slowed down the decline of net photosynthetic rate of different canopy layers at different mid-late stages.The production of N150 was relatively high,which was 4889.62 kg/hm^2.Agronomic efficiency of nitrogen fertilizer was 3.58 kg/kg.