行距对玉米—大豆套作体系中玉米产量及干物质积累与分配的影响

Effects of row spacing on yield,dry matter accumulation and partitioning of maize in maizesoybean relay strip intercropping system

合理的田间配置是间套作种植挖掘作物产量潜力的关键。通过2年大田试验,在带宽160和200 cm条件下分别设置了6个玉米行距(20、30、40、50、60和70 cm)处理,探究玉米—大豆套作体系下行距对套作玉米产量及干物质积累与分配的影响。结果表明,160和200 cm带宽下,行距变化显著影响玉米产量和单株干物质积累量,随着玉米行距的增加呈先增高后降低的趋势。2种带宽下,大豆产量随玉米行距的变宽不断降低;行距为20~50 cm时,群体产量随行距增加而显著增加,玉米行距为40和50 cm时,群体产量无显著差异;行距为50~70 cm时,群体产量呈下降趋势。2种带宽下,玉米群体干物质积累最大增长速率、快增期的干物质积累量和花后干物质同化量随窄行行距的增加亦呈先增高后降低的变化趋势,茎鞘和叶片的转运率和贡献率变化则与之相反;2种带宽均在窄行距50 cm时,玉米群体干物质积累最大增长速率和花后干物质同化量最大,分别为320.63、119.53 kg·hm^(-2)d^(-1)和376.92、140.90 g·株-1。合理的行距配置(玉米窄行距40~50 cm)可以显著增加套作玉米穗粒数,提高玉米的干物质积累速率,同时促进花后光合产物的形成,增加快增期干物质的积累量,对套作玉米产量潜力的发挥和群体产量的提高具有重要作用。

Optimum planting pattern is the key to increase crop yield potential in intercropping system. In order to investigate the effects of narrow rowspacing on the maize yield and matter accumulation and partitioning in maizesoybean relay strip intercropping system （M/S）. Field experiments were conducted with 6 marrow row spacing （20, 30, 40, 50, 60,70 cm） treatments in the 160 and 200 cm strip width,respectively in 2012 and 2013 year. The re-sults show-ed that row spacing had significant effect on maize grain yield and dr^^ matter accumulation. Yield and dry matter accumulation of maize were increased with the increasing of narrow spacing. Under 160 and 200 cm strip width, soybean yield decreased with the increasing of maize narrow row spacing; Yield of M/S significantly increased with narrow row spacing increasing from 20 cm to 50 cm, and there was no significant difference between the treat-ments of 40 and 50 cm; While the narrow row spacing more than 50 cm, population yield tend to decrease. The change trend of the maximum increasing rate, dr^^ matter accumulation of rapid increasing stage and post-anthesis as-similation were similar to maize yield. Contrary trends were observed in the maximum transportation efficiency and contribution rate of stem-sheath and leaves. The highest maximum increasing rate and post-anthesis assimilation were realized when the narrow row spacing was 50 cm under the two strip width, with the values of 320. 63, 119. 53 kg^ hm^-2d^-1 and 376. 92, 140. 90 g·plant^-1 , respectively. In general, comprehensive results showed that optimum row spacing （maize narrow row spacing was 40 cm to 50 cm） could significantly increase kernels per ear and improve the maximum increasing rate of dry matter accumulation, post-anthesis assimilate and plant dry mater accumulation of rapid increasing stage. So optimum row spacing was an important role for crop yield potential.