玉米品种根系性状和产量不同年代的演替规律及其对深松响应研究

以1970～2010年10个玉米主栽品种为试材,在深松增密条件下,研究玉米品种演替过程中根系性状和产量的变化情况。结果表明,随着年代推进,玉米单株根系性状指标(根系干重、根长、根表面积以及根系平均直径)均呈先升后降的变化趋势,1980年各指标达到最大值。根系性状指标在20～50 cm土壤中根系所占比例随着品种更替而增加,根系不断向深层土壤延伸。深松增密措施更有利于玉米新品种形成横向紧缩、纵向延伸的根系构型,不仅通过改变根系空间分布实现结构性增产,而且通过改善耕层环境实现功能性增产。

Succession Law of Root Traits and Yield of Different Maize Varieties in Different Years and Its Response to Subsoiling

Ten maize cultivars from 1970-2010 were used as the experimental materials. Under the conditions of subsoiling and densification, the changes of root traits and yield during maize succession were studied. The result showed that, the root traits(roots dry weight, root length, root surface area and root mean diameter) showed a unimodal curve change, which increased with the time and reached to the highest in 1980, then decreased thereafter. The proportion of these root traits increased with the maize cultivars succession in 20-50 cm soil depth, and the roots gradually extended into the deeper soil layer. The subsoiling and densification system favoured to the establishment of new maize cultivars, and it not only achieved a "structural" yield increase but also obtained the yield increased by the improvement of root zone environment.