Effects of N, P and K fertilizers on photosynthetic characteristics of mulberry | 氮磷钾施肥水平对桑树光合特性的影响

Chinese. [目的]研究氮磷钾施肥水平对桑树光合特性的影响。[方法]以桑树品种川826为试验材料，探讨氮磷钾不同施肥条件下桑叶的光合特性，分析其叶绿素含量、叶面积指数、净光合速率、叶片气孔导度、胞间CO2浓度、蒸腾速率等与N、P、K肥及其施用量之间的关系。[结果]氮磷钾不同施肥水平对桑树光合指标具有显著影响，适宜氮、磷、钾施肥量可以提高桑树LAI、Chla+b、Pn、Cond以及Tr，而缺少或过量施肥可使其光合能力降低；不施肥处理桑树叶片Ci显著高于施肥处理。适宜的氮、磷、钾施用水平（N 600 kg/hm2、P 210 kg/hm2、K 300 kg/hm2）可保持桑树功能叶适宜的光合状态，并能保持较长的高光合持续期。[结论]该研究阐明了桑树叶片的光合特性及不同施肥处理对桑树光合作用的调控效应，为优质高产桑园建设提供了理论依据。

English. [Objective] The aim was to research the effects of N, P and K fertilizers on photosynthetic characteristics of mulberry. [Method] In the test, Chuan 826, a variety of mulberry, was taken as an example to explore the relationships of chlorophyll content, leaf area index, net photosynthetic rate, stomatal conductance of leaf, CO2 concentration of cells in leaves and transpiration rate with N, P and K fertilizers at different quantities. [Result] N, P and K fertilizers at different quantities have effects on photosynthetic indices. In detail, N, P and K fertilizer at appropriate quantities enhanced LAI, Chla+b, Pn, Cond and Tr; Ci of mulberry leaves in control group without fertilizers was significantly higher than that in treatment groups. N, P and K at proper quantities (N at 600 kg/hm2, P at 210 kg/hm2 and K at 300 kg/hm2) would keep functional leaves well and higher photosynthetic period for a long term. [Conclusion] The research explored adjustment of photosynthetic characteristics and different treatments on photosynthesis of mulberry, providing reference for construction of excellent and highly-qualified mulberry garden.