晋西地区果树—农作物复合模式的光合特点

Photosynthetic Characteristics of Agroforestry in Western Shanxi

以晋西黄土区苹果+玉米、苹果+绿豆、核桃+玉米、核桃+绿豆4种果树—农作物复合模式为研究对象,分析与不同农作物复合的相同果树的光合速率、蒸腾速率、水分利用效率的差异和原因,果树对农作物的遮荫影响,以及净光合速率(Pn)、蒸腾速率与环境因子的关系。结果表明:苹果树对农作物的遮荫明显;苹果和核桃树与矮秆作物绿豆复合比与高秆作物玉米复合净光合速率日平均值高,蒸腾速率的日平均值略低,水分利用率高,但是在各个复合模式中的相同果树的水分利用率变化趋势基本相同;不同模式中的同种果树的净光合速率与环境因子相关系数基本相同,与光量子通量相关性最显著,其次是气孔导度。对蒸腾速率的影响因子从大到小依次为光量子通量、气孔导度、温度、相对湿度。

Taking the agroforestry modes of Apple＋maize,Apple＋Mung bean, Walnut＋maize and Walnut＋Mung bean in western Shanxi province in loess area as subject,the net photosynthetic rate,transpiration rat,water use efficiency and environmental factors of the same crop or fruit in the four were measured with a portable steady porometer（Li-6400） to study their difference and relationship.The results indicated that： the apple tree provides more obvious shading for the crops;The average net photosynthetic rate and water use efficiency of the apple tree and the walnut tree in PL and HL are higher than those in PY and HY,but they have the similar change tendency;the relationship between photosynthetic indicators and the environmental factors of the same crop and fruit in different crop-fruit ecosystems is similar.Net photosynthetic rate and light quantum flux relevance are most remarkable,and then is the blowhole leading.Based on their degree of influence,the factors of influencing transpiration rate can be arranged in the following order,PPFD,cond,temperature and relative humidity.