长期施用无机NPK肥对保护地黄瓜光合特性及产量的影响

在长期单施无机氮肥(15年)条件下,黄瓜生长发育正常,而且随着施N量的增加(试验中的最高施N处理为每年600kghm-2),叶面积显著增大,叶片的叶绿素含量、光合速率显著提高,但处理间叶片胞间CO2浓度、气孔导度无显著差异,说明不同N水平对黄瓜叶片净光合速率的作用主要是由非气孔因素造成的,长期单施无机氮肥还显著地提高了黄瓜的产量、结瓜数、座瓜率,降低了畸形瓜率。N、P、K配施可进一步提高黄瓜叶片的叶绿素含量、光合速率、产量、结瓜数和座瓜率,降低畸形瓜率,但处理间叶片胞间CO2浓度、气孔导度仍无显著差异,说明不同N、P、K配施对黄瓜叶片净光合速率的作用主要也是由非气孔因素造成的。同时,在N、P、K配施试验中,以N对黄瓜光合作用及产量的影响最大,P次之,K较小。

Effect of Long-term Application of Inorganic NPK Fertilizer on the Photosynthesis and Yield of Cucumber

On the condition of long-term single application of inorganic N fertilizer for 15 years, the cucumber normally grows and along with increasing of the amount of N fertilizer (the supreme treatment of N is 600kg hm~(-2) year~(-1)) the areas of leaf largen, the content of chlorophyll and the rate of photosynthesis remarkably increase. Cell interval CO_2 concentration and stomatal aperture of cucumber leaf in each treatment are not remarkable difference. From it we know that the effect of different level of N fertilizer on the rate of photosynthesis of cucumber is mainly affected by non-stomatal factors. What's more, long-term single application of inorganic N fertilizer remarkably improves the yield,the amount of fruit and the rate of fruit set of cucumber, and reduces the rate of odd fruit of cucumber. Combined application N,P and K further improves the content of chlorophyll of leaf,the rate of photosynthesis,the yield,the amount of fruit and the rate of fruit set, and reduces the rate of odd fruit. Cell internal CO_2 concentration and stomatal aperture of cucumber leaf in each treatment are not also remarkable difference. From it we can know that effect of Combined application N,P and K on the rate of photosynthesis of cucumber leaf is also affected by non-stomatal factors. Meanwhile in the experiment of Combined application N,P and K the effect of N on photosynthesis and yield of cucumber is greater than that of P and the effect of K is the least.