带宽和株距对带状间作大豆物质积累分配及产量形成的影响

Effects of bandwidth and plant spacing on biomass accumulation and allocation and yield formation in strip intercropping soybean

间套作系统中合理的田间配置能改善作物生长环境,增加系统产量。为进一步完善西南地区大豆-玉米带状间作系统高产高效的田间配置技术,本研究以大豆-玉米带状间作为研究对象,采用二因素裂区试验设计,综合分析2.0 m(B1)和2.4 m(B2)2个带宽与9 cm(P1)、11 cm(P2)、14 cm(P3)、18 cm(P4)4个株距对大豆物质积累分配、籽粒灌浆和产量的影响。结果表明,B2带宽下各株距处理的净光合速率均高于B1,其2年平均值在B2下较B1增加14.26%;相同带宽下净光合速率在B1P4和B2P4达到最大,开花期较B1P1和B2P1增加13.57%和25.21%。2个带宽下大豆群体物质积累均随株距增加呈先增后减的趋势且分别在B1P3和B2P2下达到最大,完熟期B2较B1增加9.82%~22.08%。同时,带宽与株距的增加促进了大豆花后物质的积累与向籽粒的转移,与B1相比,B2处理使大豆花后干物质积累量与干物质转移量分别增加13.82%~28.01%和13.38%~37.76%,籽粒物质积累占比增加到41.80%~44.26%。物质积累的增加改善籽粒灌浆过程,B2带宽下籽粒灌浆活跃期(D)较B1延长2~3 d;2种带宽下平均灌浆速率均在P4达到最大且分别较P1增加5.80%和6.58%。产量结果表明,大豆-玉米带状间作模式中,带宽和株距的增加降低了群体有效株数,增加了单株粒数和百粒重;B2带宽下的大豆产量较B1增加22.32%~36.87%,2个带宽下分别在B1P3和B2P2达到最大值,2年间较B1P1和B2P1增加17.83%~26.44%和10.71%~10.76%。综上所述,2.4m带宽下大豆株距为11 cm时能有效改善大豆花后干物质积累和分配,促进籽粒灌浆,增加单株粒数和百粒重,提高大豆群体产量,实现大豆-玉米带状间作系统的高产高效。

Reasonable field configuration can improve crop growth environment and increase system yield in intercropping systems.To further improve the field configuration technology for high yield and efficiency in the soybean-maize strip intercropping system in Southwest China,the soybean-maize strip intercropping system was used as the research object,and two factor split zone design was adopted.The effects of two bandwidths of 2.0 m(B1)and 2.4 m(B2)and four plant spacings of 9 cm(P1),11 cm(P2),14 cm(P3),and 18 cm(P4)on soybean biomass accumulation,allocation,grain filling,and yield were comprehensively analyzed.The results showed that the net photosynthetic rate of each plant spacing treatment under B2 bandwidth was higher than that of B1,and the two–year average increased by 14.26%compared with B1 under B2.At the same bandwidth,the net photosynthetic rate reached the maximum in B1P4 and B2P4,which increased by 13.57%and 25.21%compared with B1P1 and B2P1 at flowering stage,respectively.The biomass accumulation of soybean population increased and then decreased with the increase of plant spacing under the two bandwidths,and reached the maximum at B1P3 and B2P2,respectively,and B2 increased by 9.82%–22.08%compared with B1 at maturity stage.And the increase of bandwidth and plant spacing promoted the accumulation and transfer of soybean post-flowering matter to grain.Compared with B1,post-flowering dry matter accumulation and dry matter transfer increased by 13.82–28.01%and 13.38%–37.76%under B2 treatment,respectively,and the proportion of grain matter accumulation increased to 41.80%–44.26%.The increase of biomass accumulation improved the grain filling process,and the active grain-filling period(D)of soybean under B2 was extended by 2–3 days compared with B1.The mean grain-filling rate reached its maximum at P4 and increased by 5.80%and 6.58%compared with P1 under the two bandwidths.The yield results showed that,with the increase of bandwidth and plant spacing,the effective plants decreased,and the seeds per plan and 100-seed weight increased in the soybean-maize strip intercropping model.The soybean yield under B2 bandwidth increased by 22.32%–36.87%compared with B1,it reached the maximum in B1P3 and B2P2 under the two bandwidths,respectively,and increased by 17.83%–26.44%and 10.71%–10.76%compared with B1P1 and B2P1 for two years.In summary,the soybean plant spacing of 11 cm at the bandwidth of 2.4 m can effectively improve the post-flowering dry matter accumulation and allocation,promote grain filling,increase the number of seeds per plant and 100-seed weight,improve soybean population yield,and achieve the high yield and high efficiency in the soybean-maize intercropping system.