品种与施肥对次生盐碱地牧草光合特性的影响

摘要

通过正交设计 L18（61×36）在宁夏盐池次生盐碱地进行草地建植试验，探讨牧草品种、有机肥、NKP 肥及苦豆子秸秆对牧草光合特性的影响。结果表明：正交设计方法得到提高净光合速率（Pn）、气孔导度（Gs）、水分利用效率（WUE）、叶绿素含量及降低胞间 C02浓度（Ci）的最佳组合为草木樨（Melilotus offcinalia）＋有机肥36 t・hm －2＋NPK（N 165 kg・hm －2、P 135 kg・hm －2和 K 135 kg・hm －2 ）＋秸秆15 t・hm －2 ，这与 Pn 、Gs 、WUE 、叶绿素含量最高及 Ci 最低的处理15相一致，证实了正交设计结果的可靠性；4个因素对蒸腾速率（Tr）、Pn 、Gs 及 Ci 的影响程度大小均为品种＞有机肥＞ NPK ＞秸秆，对 WUE 及叶绿素含量的影响程度大小为品种＞ NPK ＞有机肥＞秸秆；品种和有机肥对 Pn 、Tr 、Gs 、WUE 及叶绿素含量影响极显著（ P ＜0．01），NPK 对 Pn 、Gs 、WUE 及叶绿素含量影响极显著（ P ＜0．01），对 Tr 和 Ci 影响显著（P＜0．05），苦豆子秸秆对 Pn 和 WUE 影响极显著（ P ＜0．01）；豆科的 Pn 、Tr 、Gs 、WUE及叶绿素含量显著大于禾本科（P＜0．05），草木樨的 Pn 、Gs 、WUE 及叶绿素含量显著高于紫花苜蓿（Medicago sati－va）和沙打旺（Astragalus adsurgens），禾本科披碱草（Elymus cylindricus ）的 Pn 、WUE 及叶绿素含量显著高于扁穗冰草（Agropyron cristatum）和蒙古冰草（Agropyron mongolicum Keng）；相关分析表明，Pn 与 Tr 、Gs 、WUE 及叶绿素含量呈极显著正相关（P＜0．01），与 Ci 呈极显著负相关（P＜0．01）。%To compare the effects of species ,organic manure ,NPK and sophora alopecuroides straw on leaf photo-synthetic characteristics ,an artificial pasture planting in Ningxia in arid sandy area using L 18 (61 × 36 ) orthogonal test was implemented .The results showed that the optimal combination to enhance net photosynthetic rate ( Pn) ,stomatal con-ductance (Gs) ,water use efficiency (WUE) ,chlorophyll content and intercellular CO2 concentration(Ci) was to use Melilotus offcinalia + organic manure 36 t・hm - 2 + NPK (N 165 kg・hm - 2 ,P 135 kg・hm - 2 and K 135 kg・hm - 2 ) +straw 15 t・hm - 2 .The combination was consistent with the Treatment 15 that had the highest Pn ,Gs ,WUE ,chloro-phyll content and lowest Ci .The influencing effects on transpiration rate (Tr) ,Pn ,Gs ,Ci were in the order of species> organic manure > NPK > straw and WUE ,and for chlorophyll content ,the order was species > NPK > organic manure> straw .The effects of species and organic manure on Pn ,transpiration rate ,Gs ,WUE and chlorophyll content were highly significant (P< 0 .01) ,and those of NPK on Pn ,Gs ,WUE and chlorophyll content were highly significant (P< 0 .01) but significant ( P< 0 .05) on transpiration and rate Ci .Effects of straw on Pn and WUE were highly signifi-cant ( P< 0 .01) .Legume was significantly ( P < 0 .05) higher in Pn , Tr , Gs , WUE and chlorophyll content than gramineae .Melilotus suaveolens had stronger productive performance than Medicago sativa and Astragalus adsurgens , and Elymus cylindricus had higher Pn , WUE and chlorophyll content than Agropyron cristatum and Agropyron mon-golicum Keng .Pn had highly significant positive correlations with Tr ,Gs ,WUE and chlorophyll content and significant negative correlation with Ci (P< 0 .01) .