水肥耦合对紫花苜蓿叶绿素含量和硝酸还原酶活性的影响

Coupling Effect of Water and Fertilizer on Chlorophyll Content and Nitrate Reductase Activity in Alfalfa Leaves

在温室盆栽条件下,以氮、磷、水用量和配比作为变量,以叶绿素含量和硝酸还原酶活性为目标函数建立方程,研究水肥耦合对敖汉苜蓿叶绿素含量和硝酸还原酶活性的影响。结果表明：（1）叶绿素含量和硝酸还原酶活性与氮、磷、水密切相关,呈二次幂函数关系。（2）叶绿素回归方程中,各因素的作用为氮〉磷〉水,且氮为正值,磷、水为负值,磷—水交互作用为正值。硝酸还原酶回归方程中,各因素的作用为水〉氮〉磷,且都为正值,氮—水及磷—水交互作用为正值。（3）叶绿素含量最高的处理为N 300kg/hm2、P2O50kg/hm2、土壤含水量5%~10%,叶绿素含量为3.25mg/g;硝酸还原酶活性最高的处理为N 300kg/hm2、P2O5450kg/hm2、土壤含水量5%~10%,硝酸还原酶活性为8.59μg/（g.h）。

Taking Medicago sativa L.cv.Aohan as experimental material,the ternary quadratic regression equations were established by using fertilizer quantities of nitrogen,phosphorus and irrigation as variables and using chlorophyll and nitrate reductases content in alfalfa as target function,coupling effect of water and fertilizer on chlorophyll and nitrate reductase content in alfalfa leaves were studied in greenhouse.The results showed that：（1） The content of chlorophyll and nitrate reductase activity were closely related to nitrogen,phosphorus,water and the relation were quadratic power function.（2） In the regression equation of chlorophyll,the role of each factor was： nitrogenphosphoruswater,and nitrogen was positive;phosphorus and water was negative;phosphorus—water interaction was positive.In the regression equation of nitrate reductase,the role of various factors was：waternitrogenphosphorus and all were positive;nitrogen—water and phosphorus—water interaction were positive.（3） The treatment for highest chlorophyll content was： N 300kg/hm2,P2O5 0kg/hm2,soil moisture 5%~10%,the content was 3.25mg/g.The treatment for highest nitrate reductase activity was：N 300kg/hm2,P2O5 450kg/hm2,soil moisture 5%~10%,the content was 8.59μg/（g· h）.