玉米/大豆套作下作物叶片氮、磷动态特征及其相关性分析

摘要

A field experiment was conducted to investigate the dynamic changes of leaf N concentration and P concentration of maize and soybean at different growth stages,and analyze their relations in the typical maize/soybean relay strip intercropping system and the soybean monoculture.The soybean (Glycine max L.Merr.)cultivars,Gongxuan1 and Guixia3,and the maize (Zea mays L.) cultivars,Denghai 605,Chuandan 418 and Yayu13,were selected in this study.The N concentrations of leaves of two soybean cuhivars at the V3 stage are lowest,while the concentrations are highest compared with those of other stages.The leaf N and P concentrations of the soybean intercropping with Yayu13 are 5.81％ and 38.56％ higher than those of the soybean monoculture.At the same time,the N∶P ratio of the relay intercropped soybean leaves is lower than that of the monoculture.After the R1 stage,these characteristics are not appeared.For maize,the change trend of leaf P concentration is a low-high-low mode through the growth stage,and the leaf N concentration is lowest at the R6 stage.In addition,the N P ratios of maize and soybean leaves in Renshou are higher than those in Ya' an.The correlation between the N and P concentration of leaves of maize and soybean is significant (r ＞ 0.46,P ＜ 0.05),especially the P concentration and the N∶P ratio (P ＜ 0.01).%在田间小区试验条件下,以登海605(紧凑型)、川单418(半紧凑型)、雅玉13(松散型)3个玉米品种,贡选1和桂夏3两个大豆品种为试验材料,采用玉米/大豆套作种植模式,在仁寿和雅安试验点研究玉米拔节期、大喇叭口期、子粒建成期和成熟期以及大豆苗期、始花期和鼓粒期叶片氮、磷养分动态规律,分析玉米和大豆叶片氮磷含量之间的相关性.结果表明,两大豆品种无论是净作还是套种,叶片氮含量在苗期最低,磷含量在苗期最高；大豆与雅玉13套作比净作其叶片氮和磷含量分别高出5.81％和38.56％以上,而套作大豆叶片氮磷比值却低于净作,仁寿试验点高于雅安试验点,始花期之后净、套作大豆叶片氮磷含量及其比值变化规律不明显.三种株型玉米叶片磷含量随生育期呈现低—高—低的规律,其中松散型玉米品种雅玉13叶片磷含量最高；而叶片氮含量在子粒建成期之前变化幅度较小,成熟期达到最低.同样,玉米氮磷比值仁寿试验点高于雅安试验点.通过叶片氮和磷含量及其比值间的相关性分析,玉米和大豆叶片氮、磷含量与其之间的比例相关性达到显著水平(r ＞0.46,P＜0.05),特别是叶片磷含量与氮、磷比之间的相关性极显著(P＜0.01).