匀播和施氮量对冬小麦群体、光合及干物质积累的影响

Effect of uniform pattern and N application rate on colony,photosynthesis and dry matter accumulation of winter wheat

为探明匀播方式和施氮量对冬小麦群体、光合及干物质积累的影响,选用’新冬22号’(’XD 22’)和’新冬46号’(’XD 46’)为材料,采用裂区试验设计,主区播种方式设匀播(UN)和常规条播(DR)2个处理,副区施氮量设0(N0)、150(N150)、300(N300)、450(N450)和600(N600)kg/hm^(2)5个水平,测定冬小麦分蘖成穗、叶面积指数、净光合速率、干物质转运、分配及产量等指标。结果表明:1)一定范围内,随着施氮量增加,小麦单株茎数、成穗数和群体叶面积指数(LAI)增大;与DR相比,UN小麦单株茎数、成穗数、群体叶面积指数也增大,尤其增大了灌浆期叶面积指数。2)随着施氮量增大;匀播提高了小麦叶片净光合速率,尤其提高了冠层中、下部叶片的净光合速率。3)随着施氮量增大,小麦花前茎鞘、叶片干物质积累量、营养器官干物质转运量和转运率、植株营养器官干物质转运对籽粒的贡献率、穗数、穗粒数及产量均先增大后减小;与DR相比,UN提高小麦植株营养器官干物质转运量、转运率、穗数、穗粒数和产量,2个品种于N300和N450水平下产量达到最大;在N0、N150、N300、N450和N600水平下,’新冬22号’UN比DR分别增产11.79%、5.36%、4.55%、5.24%和8.73%;’新冬46号’分别增产10.98%、7.07%、14.81%、14.55%和16.10%。综上所述,匀播方式改善了群体结构,提高群体中、下层的光合特性,促进营养器官干物质积累及向籽粒中的转移,进而提高产量,尤其施氮量为300和450kg/hm^(2)增产效果最佳。

In order to explore the effect of uniform planting pattern and N application rate on the colony,photosynthesis and dry matter accumulation of winter wheat,experiments were carried out to determine the tillering heading,leaf area Index,net photosynthetic rates,dry matter accumulation,transport and yield formation of winter wheat.’Xindong 22’(’XD 22’)and’Xindong 46’(’XD 46’)were taken as study material.Split-plot experiment design was applied,the main plot was the planting patterns of the main plot were uniforming(UN)and drilling(DR),and the N application rate levels of subplot were 0,150,300,450 and 600 kg/hm^(2),where were marked as N0,N150,N300,N450 and N600,respectively.The results showed that:1)With the increase of N application rate,the number of stems per plant,number of panicles,and LAI of wheat increased.The number of stems per plant,number of panicles and LAI were also increased,especially at the filling stage.2)With the increase of N application rate,the net photosynthetic rate in wheat leaves were firstly increased and then decreased.Uniform planting increased the net photosynthetic rate of wheat leaves,especially the net photosynthetic rate of middle and lower canopy leaves.3)With the increase of nitrogen application,the stem sheath,leaf dry matter accumulation,dry matter transfer volume and transport rate of vegetative organs,dry matter transport contribution rate of vegetative organs to grains,spikelet,grains per spike and yield of wheat before flower first increased and then decreased.Compared with the regular planting,the uniform planting increased the dry matter transport volume,transport rate and yield of vegetative organs of wheat plants,spikelet,grains per spike and the yield of the two varieties reached the maximum at the level of N300 and N450.At the levels of N0,N150,N300,N450 and N600,the production of uniform planting ratio of ’XD 22’ respectively increased by 11.79%,5.36%,4.55%,5.24%,8.73%,and of’XD 46’increased by 10.98%,7.07%,14.81%and 14.55%,16.10%.To sum up,the uniform planting pattern improved the population structure,the photosynthetic characteristics of middle and lower layer of winter wheat plants.It also promoted the transfer of organs to grain dry matter accumulation and nutrition,and increase production.and the yield increases were the highest at N applications of 300 and 450 kg/hm^(2).