氮磷钾配比对油楠幼苗光合生理特性的影响

【目的】研究不同施肥组合对油楠幼苗光合生理特性的影响，为确定油楠苗期最佳施肥量提供参考依据。【方法】采用L9（3^4）正交试验设计：N（155、310、465mg／株）、P20，（12、24、36mg／株）、KEO（56、112、168mg／株），以不施肥为对照处理，测定不同处理对油楠苗期净光合速率（Pn）、蒸腾速率（Tr）、气孔导度（Gs）、水分利用率（WUE）和叶绿素含量的影响，探讨施肥水平对光合生理指标的影响，寻求最佳施肥方案。【结果】在对各光合生理指标的影响效应上，K〉N〉P，低水平的NP配比更有利于提高油楠叶绿素含量和净光合速率，适当增加施K量能显著提高油楠叶绿素含量和净光合速率。【结论】促进油楠幼苗的净光合速率和改善光合生理的最佳施肥组合是N2P2K3，推荐最佳施肥量为N221．52m琳、P24mg／株、K167．99mg／株。

Effects of N, P and K formula on photosynthetic-physiological properties of Sindora glabra seedling

Objective]Effects of different fertilizer mixtures on photosynthetic-physiological properties of Sindora glabra seedlings were observed to provide references for determining the optimal application rate of fertilizers. Method]By using orthogonal design L9（3^4）, various combination of different amount of N（155, 310, 465 mg/seedling）, P（12, 24, 36 mg/seedling）, K（56, 112, 168 mg/seedling）,and the control （no fertilizer） were applied to Sindora glabra to detect its photosynthesis rate （Pn）, transpiration rate （Tr）, conductivity （Gs）, water use efficiency （WUE） and chlorophyll content. The relationship between fertilization and photosynthetic-physiological index was analyzed to find out the best fertilizer combination. Result]The influencing order on photosynthetic-physiological indexes was K〉N〉P. Low N and P level was beneficial for improving chlorophyll content and net photosynthesis rate, but high level meant less effect. Moderate increase of K fertilizer could evidently improve chlorophyll content and net photosynthesis rate of Sindora glabra. Conclusion]Generally speaking,N2P2K3 was the optimal combination,and the recommended application rates of N,P and K were 221.52,24 and 167.99 mg/seedling, respectively.