水肥耦合条件下春小麦叶片的光合作用

Leaf photosynthesis of spring wheat under water and fertilizer coupling

采用312-D最优饱和设计,在辽宁西部半干旱区进行了田间春小麦光合作用试验研究．结果表明:叶片光合速率与籽粒产量正相关．水肥单因子对叶片光合速率影响的大小顺序是,氮>水>磷．交互耦合作用对叶片光合速率影响的大小顺序为:氮与水耦合>氮与磷耦合>磷与水耦合．水肥耦合促进叶片光合速率提高的主要原因是:扩大了叶面积、提高了叶片蒸腾速率、增大了叶片气孔导度、提高了胞内水浓度、降低了胞内二氧化碳浓度．单叶光合速率高于7．5×10-3μmol／s的水肥优化管理方案是:施氮量为323．4-399．9 kg／hm2、施磷量为65．8-105．7 kg／hm2、灌水量为276．1-353．2 mm．

With 312-D optimized saturation design, field experiments were conducted in semi-arid region in the western Liaoning to study photosynthesis on spring wheat. Results showed that leaf photosynthesis rate was in positive correlation with the yield. Water and fertilizer affect leaf photosynthesis rate, the effect order being nitrogen〉water〉phosphorus and that of interaction being nitrogen and water coupling 〉nitrogen and phosphorus coupling 〉phosphorus and water coupling. Main reasons for higher photosynthesis rate under water and fertilizer coupling were that the coupling with water and fertilizer broadened leaf area, increased transprition rate, expanded stoma condction, increased water concentration in leaf, reduced CO2 concentration in leaf. Simulative result of optimized scheme showed that photosynthesis rate of one whole leaf was above 7.5× 10^-3 μmol/s, amounts of water and fertilizer were nitrogen 323.4-399.9 kg/hm^2, phosphorus 65.8--3105.7 kg/hm^2, irrigation water 276.1-3 353.2 mm, respectively.