播种量和施氮量对垄沟覆膜栽培冬小麦花后生理性状的影响

为协调冬小麦个体与群体间的关系,充分发挥旱作条件下垄沟栽培优势,以冬小麦品种小偃22为材料,采用二元二次正交旋转组合设计,通过田间试验研究了垄下集中施肥、垄上覆膜、膜际种植模式下播种量和施氮量对冬小麦花后生理性状的影响.结果表明:花后叶面积指数、旗叶叶绿素含量和净光合速率均随施氮量的增加而增加.灌浆前中期叶面积指数随播种量的增加呈先增后稳的趋势;灌浆后期叶面积指数随播种量的增加而降低.随播种量的增加,旗叶的叶绿素含量和净光合速率降低,单株产量呈先减少后增加的趋势.适宜的播种量可以协调个体与群体间的矛盾,而适量增施氮肥有利于花后小麦生理性状的改善和产量的提高.在供试条件下,小偃22在播种量112.5 kg hm-2与施氮量180 ～222 kg N·hm-2配置时,个体与群体的关系比较协调,花后叶面积指数较高,群体结构适宜,而且旗叶叶绿素含量、净光合速率和单茎产量较高,能获得高产.

Effects of seeding rate and nitrogen fertilization rate on physiological traits of winter wheat after anthesis in a field with plastic mulched rides and unmulched furrows

Taking winter wheat cultivar Xiaoyan 22 as test material, a field experiment with central composite rotatable design was conducted to investigate the effects of seeding rate and nitrogen (N) fertilization rate on the physiological traits of the cultivar after anthesis under ridge-furrow cultivation with plastic film mulching, aimed to harmonize the relationships between winter wheat population and its individuals and to fully use the advantages of ridge-furrow cultivation in dry land areas. With increasing N fertilization rate, the leaf area index and the flag leaf chlorophyll content and net photosynthesis rate after anthesis increased; with increasing seeding rate, the leaf area index increased first and was stable then at early and middle milking stages but decreased at later milking stage, the flag leaf chlorophyll content and net photosynthesis rate decreased, and the grain yield per plant increased after an initial decrease. Appropriate seeding rate could optimize the relationships between winter wheat population and its individuals, and optimal N fertilization rate benefited the improvement of winter wheat physiological traits after anthesis and the enhancement of winter wheat yield. Under our experimental condition, seeding rate 112.5 kg x hm(-2) plus N fertilization rate 180-222 kg N x hm(-2) is a scheme beneficial to optimize the relationships between winter wheat population and its individuals and to establish a good winter wheat community structure with a reasonable leaf area index after anthesis, higher flag leaf chlorophyll content and net photosynthesis rate, higher grain yield per plant, and high yield per unit area.