夏大豆群体内植株分布对干物质积累分配及产量的影响

试验于2007—2008年进行, 在相同密度下,设置5种处理，即行距×株距分别为A：18 cm×18 cm，B：27 cm×12 cm，C：36 cm×9 cm，D：45 cm×7.2 cm，E：54 cm×6 cm，研究其对干物质积累分配及产量的影响。结果表明，A、B处理叶面积指数分别高出E处理30%、25%，差异显著；A、B处理干物质总量分别高于E处理20%、19%，差异显著，C、D、E处理间无显著差异；A、B、C处理分枝豆荚重量和总豆荚重量显著高于E处理，D、E间无显著差异；A、B处理产量分别高于E处理11%、10%，差异显著，C、D、E处理间无显著差异。植株分布均匀性变差使群体内部对资源的利用产生激烈竞争，降低了群体叶面积指数，从而使干物质积累量以及分配比例减少，最终导致产量下降。因此，在确定的种植密度下较均匀的植株分布能够使光合产物积累分配合理，形成较高经济产量。由于A、B处理间无显著差异，而B处理方便于实际生产过程中的栽培管理，所以，本文推荐B处理为大田生产的最优群体。

Effect of Plant Density Patterns in Population on Dry Matter Accumulation, Partitioning and Yield in Summer Soybean

The experiment was carried out in 2007–2008. The five plant distribution patterns under the same plant density were A: 18 cm×18 cm, B: 27 cm×12 cm, C: 36 cm×9 cm, D: 45 cm×7.2 cm, E: 54 cm×6 cm in row spacing (cm) ×plant spacing (cm), respectively. The results showed that the average leaf area index in A and B treatments was 30% and 25% significantly higher than that in E treatment respectively in the whole growing period access two years. Compared with in E treatment the dry matter accumulation in A and B treatments was increased significantly by 30%, 19% at the whole growing stage in two years, respectively, C, D, and E treatments had no significant difference between each other. The number of pods and pods per branch in A, B, and C treatments were significantly higher than these in E treatment at the whole growing stage in two years, respectively, while there was no significant difference between D and E treatments. A and B treatments were 11%, 10% significantly higher than E treatment in average yield in the two years, respectively, while there was no significant difference between C, D, and E treatments. The leaf area index (LAI) decreased with the increase of row spacing that caused fierce competition for resources, and thus the reduction in dry matter accumulation and distribution, and eventually led the yield to decline. These results indicate that summer soybean population with relatively uniform plant distribution leads to rational dry matter distribution, and higher yield. A and B treatments had no significant difference but B treatment was better for cultivation and management in the actual production process, suggesting that B treatment is the best plant distribution for a population.