施氮量对茶树生长及叶片光合特性的影响

采用水泥池培育的方法,研究了不同氮肥施用量对茶树生长和叶片光合特性的影响。试验设置4个施氮水平,分别为0kg N/hm2（CK）、112.5 kg N/hm2（N1）、225 kg N/hm2（N2）和450 kg N/hm2（N3）。结果表明：施氮显著促进茶树生长,施氮处理茶叶产量比CK显著提高116.98%～141.51%（P〈0.05）,但施氮处理间差异不显著（P〉0.05）;施氮处理茶树叶片叶绿素总量提高30.56%～72.67%,类胡萝卜素含量降低13.37%～29.74%,并与CK差异显著（P〈0.05）;施氮处理茶树叶片净光合速率比CK显著提高14.88%～17.26%（P〈0.05）,但施氮处理间差异不显著（P〉0.05）;氮肥施用提高茶树叶片气孔导度、蒸腾速率和水分利用效率。适量的施氮可提高茶树叶片叶绿素含量、提高光合速率,促进茶树生长和茶叶产量提高;但随着氮肥施用量的增加,单位氮肥对茶树生长的促进效应降低。

Effect of Nitrogen Application Rate on the Growth and Leaf Photosynthetic Characteristics of Tea

Effects of nitrogen application rate on the growth and leaf photosynthetic characteristics of tea by the cement pond cultivation experiment were studied in the paper. There were four treatments of N application, 0（CK）, 112.5（N1）, 225（N2）, 450（N3）kg/hm2, respectively. The results showed that nitrogen application significantly promoted tea growth, and the tea productions of nitrogen application treatments increased significantly than CK from 116.98% to 141.51%（P〈0.05）, but there were no significant difference（P〈0.05）in the 3 treatments. The total chlorophyll contents of tea leaves in 3 N application treatments increased from 30.56% to 72.67%, the carotenoid contents in which decreased from 13.37% to 29.74% and with significant difference to CK（P〈0.05）. The net photosynthetic rates of tea leaves in 3 N application treatments increased significantly from 14.88% to 17.26%（P〈0.05）than CK, however there were no significant difference（P〈0.05）in the N treatments. So it indicated that appropriate N application rate could improve the chlorophyll contents, net photosynthetic rates, growths and productions of tea, but the effects of promotion of unit N application rate decreased with the higher N application rate.