膜下滴灌氮肥运筹对花生光合和抗氧化特性的影响

Effects of Nitrogen Allocation on Photosynthesis and Antioxidant Characteristics of Peanut under Mulching Fertigation

为研究膜下滴灌氮肥运筹对花生光合和抗氧化特性的影响,在氮肥总量不变的情况下,以花生品种青花7号为材料,设置了6种氮肥运筹方案。各处理基施∶花针期追肥∶结荚期追肥的氮肥比例分别为5∶0∶0(T2),3∶1∶1(T3),2∶2∶1(T4),1∶2∶2(T5),1∶3∶1(T6),0∶3∶2(T7),以不施氮肥处理(T1)为对照。结果表明:与其他处理相比,T6处理显著提高了不同生育时期叶片的光合速率、气孔导度、叶绿素含量、超氧化物歧化酶、过氧化物酶和过氧化氢酶活性,显著降低了叶片丙二醛含量。特别是在花生生长发育后期仍然使叶片保持较高的光合速率和抗氧化酶活性,降低膜脂过氧化程度,延缓叶片衰老,从而利于产量的形成。综上,本研究条件下,青花7号以基施∶花针期追肥∶结荚期追肥按1∶3∶1比例为最优氮肥运筹方案。

In order to study the effects of nitrogen management on photosynthesis and antioxidant characteristics of peanut under mulching drip irrigation, six nitrogen management were set up with peanut cultivar Qinghua7 as material under the same amount of nitrogen application. The proportions of nitrogen fertilizer in each treatment were 5∶0∶0(T2), 3∶1∶1(T3), 2∶2∶1(T4), 1∶2∶2(T5), 1∶3∶1(T6), and 0∶3∶2(T7) at basal application∶topdressing at flowering-pegging stage∶topdressing at pod-bearting stage, respectively. No nitrogen fertilizer application treatment(T1) was taken as control. The results showed that compared with other treatments, T6 significantly increased photosynthetic rate, stomatal conductance, SPAD value, superoxide dismutase activity, peroxidase activity and catalase activity whereas decreased MDA content in leaves at different peanut growth stages. Particularly, in the later period of peanut growth and development, the leaves could maintain high photosynthetic rate and antioxidant enzyme activity so as to reduce the degree of membrane lipid peroxidation, delay leaf senescence, and therefore contribute to the higher productivity. Consequently, under the circumstance of the present experiment, the nitrogen ratio of basal application∶topdressing at flowering-pegging stage∶topdressing at pod-bearing stage as 1∶3∶1 was the optimum nitrogen management for peanut cultivar Qinghua7.