江淮历代冬小麦主栽品种生产力与氮肥效率的比较

于2007～2009年在江苏省丹阳市,以江淮地区20世纪50年代至今冬小麦代表性主栽品种为材料,设置两个氮肥水平,研究该区冬小麦生产力与氮肥效率的变化特征.结果显示,冬小麦生物学产量随年代变迁呈现递减趋势,低氮水平下1980年之前品种的生物量显著高于1980年之后的品种.冬小麦籽粒产量呈现递增趋势,高氮水平下1980年之前品种的籽粒产量明显低于1980年之后的品种.1980年之前品种的生产力对氮肥的响应不明显,而1980年之后品种的生产力则随施氮量增加而明显提高.1980～1990s品种与2000s品种之间的生物量与籽粒产量差异均不显著.低氮水平下,不同年代品种间的茎叶氮含量、籽粒氮含量、地上植株氮积累量、籽粒氮积累量和氮偏生产力无明显变化趋势；高氮水平下,上述各氮指标均随年代变迁而呈现递增趋势,尤其是植株氮积累总量和氮偏生产力显著提高.1980～1990s品种的各氮指标与2000 s品种的相应指标之间无明显变化趋势.冬小麦品种的演变过程是遗传改良与氮肥施用增加的互促过程,现代品种在高氮水平下呈现出增产优势.

Differences in productivity and nitrogen use efficiency of winter wheat between cultivars released in different times in Jianghuai area

This experiment was conducted to study the differences in winter wheat productivity and N use efficiency between the main cultivars released since 1950s with two N levels(N150:150 kg·hm-2,N300:300 kg·hm-2)in Yanling town,Danyang city,Jiangsu province in 2007~2009.Our results showed that winter wheat biomass decreased with time.The biomass of the cultivars released before 1980 was significant higher than that of the cultivars released after 1980 under the lower N application level.The grain yield increased with time.The grain yield of the cultivars released before 1980 was significant lower than that of the cultivars released after 1980 under the higher N application level.There were no significant differences in the biomass and grain yield between the cultivars of 1980~1990 s and 2000 s.Under lower N application level,there were no significant differences in the plant N contents,N accumulation amounts and N use efficiency between the cultivars released in different times.However,these N indexes increased with time under the higher N application level,especially the N accumulation amount and N use efficiency(p<0.05).No significant difference was found in these N indexes between the cultivars released in 1980~1990 s and 2000 s.The above evidences demonstrate that the cultivar change process of winter wheat is an interaction of genetic improvement ant N application increase,and modern cultivars own greater yield advantage under high N application level.