缓释肥对杉木容器苗生长和光合特性的影响

Effects of slow release fertilizers on growth and photosynthesis characteristics of Cunninghamia lanceolata container seedlings

[目的]探讨杉木容器苗生长和光合特性对不同缓释肥施用量的响应,为杉木幼苗的高效培育提供依据。[方法]以杉木轻基质容器苗为研究材料,共设置6个处理:T 1~T 5分别表示缓释肥施用量为200、400、800、1600和3200 g·m^(-3),以不施缓释肥为对照(CK)。分析杉木容器苗生长量及叶绿素含量、叶绿素荧光参数和气体交换参数的变化,筛选出适合其生长的施肥量。[结果](1)缓释肥可以显著促进容器苗苗高和地径的生长及生物量的积累,且在T 4处理时达到最大值。(2)叶片光合色素含量随缓释肥施用量的增加呈先升高后降低的趋势,在T 4处理时达到峰值。(3)各施肥处理中叶片最大荧光(F_(m))、可变荧光(F_(v))、PSⅡ最大光化学效率(F_(v)/F_(m))、PSⅡ潜在活性(F_(v)/F_(o))和光化学猝灭系数(Qp)均显著高于CK,且各指标均在T 4处理达到最大值,而初始荧光(F_(o))和非光化学猝灭系数(NPQ)显著低于CK。(4)随着施肥量的增加,叶片净光合速率(P_(n))、气孔导度(G_(s))和蒸腾速率(T r)整体上呈增长趋势,且各指标均显著高于CK,而叶片胞间CO_(2)浓度(C_(i))则显著低于CK。[结论]T 4处理(施肥量1600 g·m^(-3))最适合杉木幼苗生长,通过提高叶片光合色素含量,增强叶片对光能的利用率及光合效率,进而促进幼苗生长。

[Purpose]To study the growth and photosynthetic characteristics responses of Cunninghamia lanceolata container seedlings to different amounts of slow-release fertilizers(SRF).It provides basis for efficient cultivation of C.lanceolata container seedlings.[Method]C.lanceolata light-matrix container seedlings were used as experimental material.A total of six treatments were set up with different amounts of SRF[CK(0 g·m^(-3)),T 1(200 g·m^(-3)),T 2(400 g·m^(-3)),T 3(800 g·m^(-3)),T 4(1600 g·m^(-3))and T 5(3200 g·m^(-3))]to investigate the changes of seedling growth volume,chlorophyll content,chlorophyll fluorescence parameters,and gas exchange parameters.The most suitable SRF amount was selected for the growth of C.lanceolata container seedlings.[Result](1)SRF can significantly promote the height and ground diameter of seedling,and biomass accumulation.All of these indexes reached their maximum values during T 4 treatment.(2)The content of leaf photosynthetic pigment displayed first increased then decreased pattern with the increase of SRF amount,but reached its maximum value during T 4 treatment.(3)The maximum leaf fluorescence(F_(m)),variable fluorescence(F v),PSⅡmaximum photochemical efficiency(F v/F_(m)),PSⅡpotential activity(F v/F_(o))and photochemical quenching coefficient(Qp)were significantly higher than CK in each fertilizer treatment.Each index reached the maximum value of during T 4 treatment.The initial fluorescence(F_(o))and non-photochemical extinction coefficient(NPQ),however,were significantly lower than CK.(4)In terms of gas exchange parameters,the net photosynthetic rate(P_(n)),stomatal conductance(G s)and evapotranspiration rate(T r)of leaf blades showed an overall upward trend with increasing amount of fertilizers and these indexes were significantly higher than CK,while the carbon dioxide concentration(C_(i))between the leaf cells was significantly lower than CK.[Conclusion]The T 4 treatment(1600 g·m^(-3) SRF)is most suitable for the growth of C.lanceolata container seedlings,by increasing the content of photosynthetic pigments in leaves,enhancing the utilization efficiency of light energy and photosynthesis,and thus promoting seedling growth.