种间距对不同结瘤特性套作大豆物质积累、鼓粒及产量形成的影响

Effects of Row Spacing on Dry Matter Accumulation, Grain Filling and Yield Formation of Different Nodulation Characteristic Soybeans in Intercropping

【目的】间套作是实现资源高效利用、解决粮食供求矛盾的重要途径,间套作体系下作物和谐共生受种间互作强度的重要影响。本研究以玉米-大豆套作系统为研究对象,探讨玉豆种间距对不同结瘤特性大豆干物质积累与产量形成的影响。【方法】2016—2017年,连续2年进行大田试验,二因素随机区组设计,A因素为不同玉豆种间距,大豆净作(A1)与玉米大豆套作(4种玉豆种间距:30 cm,A2;45 cm,A3;60 cm,A4;75 cm,A5),B因素为3个大豆品种(贡选1号,弱结瘤;桂夏3号,中度结瘤;南豆25号,强结瘤),分析大豆干物质积累、鼓粒、产量构成的变化规律。【结果】玉豆种间距对不同结瘤大豆的物质积累分配有显著影响,鼓粒前期净作大豆的干物质积累量显著高于套作,R4期(盛荚期)达到最高;套作大豆的干物质积累则在R5期(始粒期)达到最高,并逐渐高于净作,以玉豆种间距45、60 cm下的物质积累量较高;玉豆种间距60 cm(A4)下的南豆25号在荚果分配率、成熟期干物质积累量和营养器官对荚果的贡献率等方面优于桂夏3号和贡选1号。各品种在套作下均以A4种间距下的鼓粒时间最长、达到最大鼓粒速率时的籽粒重最高,百粒重与产量最大,且与净作产量差异不显著;各玉豆种间距下以南豆25的鼓粒能力最强,A4种间距下南豆25的平均产量分别比桂夏3号、贡选1号高5.4%和6.3%。【结论】强结瘤的南豆25号能较好适应玉米大豆套作环境,且在种间距60 cm下表现最优,有利于干物质向籽粒分配和鼓粒,以增加百粒重,弥补荚数不足,达到套作与净作产量相当的目的。

【Objective】Intercropping is an important way to increase the efficient utilization of resources and to solve the contradiction between grain supply and demand.Under intercropping system,crop symbiosis is influenced by interspecific interaction intensity between the species.In this study,maize-soybean intercropping system was used to investigate the effects of strength of root interaction between maize and soybean on the dry matter accumulation and yield formation of different nodule characteristic soybeans,so as to analyze variation trend dry matter accumulation and yield formation of soybean.【Method】Field experiments were carried out for two consecutive years from 2016 to 2017 with randomized complete block factorial design:factor A was different row spacing between maize and soybean,intercropped soybean followed by different row spacing(A2:30 cm,A3:45 cm,A4:60 cm,A5:75 cm);factor B was three soybean varieties(Gongxuan 1:Weak nodulation,Guixia 3:Moderate nodulation,Nandou 25:Strong nodulation).【Result】The row spacing between soybean and maize had a significant effect on the biomass accumulation and distribution of soybean with different nodulation.Under monoculture,dry matter accumulation of soybean was significantly higher than that of intercropping,and reached the highest at R4(full pod stage).The dry matter accumulation of intercropping soybean reached the highest at R5 stage,and was gradually higher than monoculture.Soybean had a highest amount of biomass accumulation when the row spacing was 45 cm and 60 cm.In intercropping,each variety had the longest grain filling time under A4,and the maximum grain filling rate,100-seeds weight and yield were achieved under A4.Interestingly,there was no significant difference between monoculture and intercropping yield.Nandou 25 had the strongest grain filling capacity under all row spacing.Under A4,the average yield of Nandou 25 was 5.435%and 6.3%higher than that of Guixia 3 and Gongxuan 1,respectively.【Conclusion】Nandou 25 with strong nodulation could adapt to the intercropping environment well,and showed the best performance at 60 cm.It could promote dry matter accumulation and stabilize the yield through increasing grain filling rate and 100-seeds weight in intercropping.Furthermore,it could be useful to achieve the goal of stable and optimal yield in intercropping and monoculture.