不同施肥组合对沿海沙地鼓节竹发笋期生长及光合特性的影响

Effects of different fertilizer combination on growth and photosynthetic characteristics of Bambusa tuldoides during shooting period in coastal sandy land

【目的】分析不同施肥组合对鼓节竹发笋期生长及光合特性的影响,为沿海沙地鼓节竹优质栽培提供参考依据。【方法】采用氮磷钾配比(A)、施肥方式(B)和培土高度(C)3因素4水平正交试验设计对3年生鼓节竹进行施肥管理,测定不同施肥组合处理鼓节竹发笋盛期的出笋量、总叶绿素含量和相关光合参数,采用双曲线修正模型拟合光响应曲线,分析光合特性与出笋量和光合色素的关系,筛选出沿海沙地栽培鼓节竹的最优施肥模式。【结果】对鼓节竹发笋期的极差(R)分析结果显示,影响出笋量的因素排序为氮磷钾配比>培土高度>施肥方式,最优施肥组合为A1B3C3,即氮磷钾配比为2∶1∶1、施肥方式为丛中穴施和培土高度为20 cm最适于鼓节竹发笋期出笋。双曲线修正模型模拟鼓节竹叶片的光响应曲线拟合度>0.9900;净光合速率(Pn)先急剧增长后趋于稳定,达到光饱和点(LSP)后呈一定的下降趋势;各施肥组合处理下,蒸腾速率(T_r)和气孔导度(Gs)随光强的增强呈先增大后逐渐平缓直至趋于稳定状态的变化趋势,水分利用效率(WUE)呈先急剧增长后趋于平缓到稳定状态的变化趋势,而胞间二氧化碳浓度(Ci)的变化趋势与T_r、G_s和WUE相反。相关性分析结果表明,P_n与出笋量和总叶绿素含量呈极显著正相关(P<0.01,下同),出笋量与总叶绿素含量呈极显著正相关,LSP与出笋量呈显著正相关(P<0.05)。【结论】在沿海沙地栽培鼓节竹,于发笋期以氮磷钾配比2∶1∶1进行丛中穴施并培土20 cm,可最大程度地提高其出笋量。

【Objective】The effects of different fertilization combinations on the growth and photosynthetic characteristics of Bambusa tuldoides shoots during the period of bamboo shoot development were analyzed to provide reference for the cultivation of bamboo in coastal sand land.【Method】The three-year-old B.tuldoides was fertilized and managed by three-factor and four-level orthogonal test design with nitrogen,phosphorus and potassium ratio(A),fertilization method(B)and soil height(C)as the factors.The shoot yield,total chlorophyll content and related photosynthetic parameters were determined in each fertilization combination.A hyperbolic correction model was used to fit the light response curve,and the relationship between photosynthetic characteristics,shoot output,and photosynthetic pigments was analyzed.The optimal fertilization model for B.tuldoides in coastal sand was screened.【Result】The results of the range(R)analysis on the bamboo shooting period of B.tuldoides showed that the factors that affected the amount of bamboo shoots were ranked as follows:nitrogen,phosphorus and potassium ratio>soil height>fertilization method.The optimal fertilizer combination was A1B3C3.That was,the ratio of nitrogen,phosphorus and potassium was 2∶1∶1,and the optimal fertilization method was to apply the fertilizer in the holes near shoots and the soil height was 20 cm.The hyperbolic correction model simulated the light-response curve fitting degree of bamboo leaves of B.tuldoides was>0.9900.The net photosynthetic rate(Pn)increased rapidly first and then stabilized,presented a downward trend after reaching the light saturation point(LSP).With the increase of light intensity,transpiration rate(Tr)and tomatal conductance(Gs)first increased and gradually decreased until reached a stable state.Water use efficiency(WUE)grew rapidly,flattened then tended to be steady.But the change trend of intercellular CO2 concentration(Ci)was the opposite of Tr,Gs and WUE.The correlation analysis showed that Pn was extremely positively correlated with shoot output and total chlorophyll content(P<0.01).There was extremely positive correlation between shoot output and total chlorophyll content,and there was significant positive correlation between LSP and shoot output(P<0.05).【Conclusion】When planting B.tuldoides in the coastal sandy area,the ratio of nitrogen,phosphorus and potassium being 2:1:1,applying fertilizer in holes near shoots and earthing up 20 cm soil during shooting period can largely increase the amount of B.tuldoides shoots.