苏北农田林网对小麦光合作用及产量的影响

Effects of Farmland Shelterbelt Nets on Photosynthesis and Grain Yield of Wheat in Northern Jiangsu

为了进一步研究苏北地区闭合微型农田林网对小麦的胁地效应,并探寻该类型林网小麦的光合作用变化特征。选择江苏省宿迁市2个农田林网典型乡镇为试点,按不同方位林带和不同林缘距离设置试验样方,于灌浆前期,测定不同处理样方小麦功能叶片净光合速率(Pn)及其主要影响因素光合有效辐射(PAR)、叶温(Tl)、相对湿度(RH)和蒸腾速率(Tr)、气孔导度(C)、细胞间隙CO2浓度(Ci)等;并于成熟期拷种测量小麦产量及其结构,将上述各项测定结果与对照处理分别进行对比分析。结果显示:PAR、Tr和C是Pn的主要影响因素,而Tl和RH对Pn的影响甚微;小麦单位面积穗数和每穗粒数与Pn相关显著,前两者的降低是造成林缘区域小麦减产的主要原因。

To investigate the shade effect of micro-closed type farmland shelterbelt nets on wheat in Northern Jiangsu,two typical township with farmland shelterbelt nets in Suqian city of Jiangsu province were selected as experimental sites,and the quadrats were set up according to different orientations and different distance from the forest edge.Net photosynthetic rate（Pn）,photosynthetically active radiation（PAR）,leaf temperature（Tl）,relative humidity（RH）,transpiration rate（Tr）,stomatal conductance（C） and intercellular carbon dioxide concentration（Ci） of wheat functional leaves were determined at early grain filling stage,and the yield and yield components were measured in wheat maturity stages.Determination of the above different treatment data were analyzed compared with their corresponding control,respectively.PAR,Tr and C were main factors influencing Pn,while Tl and RH had little influence on Pn.Ears per unit area and grains per ear closely correlated with Pn,and the reduction of ears per unit area and grains per ear were the main reason for low yield in forest edge area.