以郑单958为材料, 采用田间试验方法, 在50 025株/hm²、67 500株/hm²、100 050株/hm²密度下分别设两种株行距配置, 探讨增密条件下调控株行距配置对玉米根系性状及产量影响。结果表明, 3个种植密度下总体表现为小行距种植方式在0～60 cm土层内的根重密度、根长密度及根表面积密度均高于大行距处理。50 025株/hm²下吐丝期时0～60 cm土层内的根重密度和根长密度在两个株行距配置间差异显著(P<0.05), 两个株行距配置的根表面积密度在10叶展、吐丝期和吐丝后25 d差异显著(P<0.05);67 500株/hm²下不同时期两个株行距配置根重密度差异显著(P<0.05), 根长密度和根表面积密度在10叶展和吐丝后25 d差异显著(P<0.05);100 050株/hm²下, 两个株行距配置间根重密度和根长密度在10叶展和吐丝后25 d差异显著(P<0.05), 不同时期根表面积密度差异显著(P< 0.05)。同一密度下缩行增株后单株木质部伤流液体积增大, 根系供应能力增强, 产量增加, 50 025株/hm²、67 500株/hm²下产量分别提高了6.76%和4.89%。不同时期0～60 cm土层内根重密度、根长密度和根表面积密度与产量呈正相关, 其中10叶展时各根系性状均与产量呈显著正相关。

A field experiment was carried out to study the effect of changing spacing allocations on root growth and yield of maize. Maize variety Zhengdan958 was used, and six treatments were set under three densities. The results showed as follows. Generally, root weight density, root length density and root surface area density with narrow row spacing were greater than wide row spacing in 0-60 cm soil depth under each plant density. In addition, under density of 50 025 plants/ha, significant differences on root weight density and root length density were observed between two row spacing at silking stage, and also on the root surface area density at the 10-leaf stage, silking stage and 25 days after silking. Moreover, under density of 67 500 plants/ha, root weight density at three stages and root length density and root surface area density at 10-leaf stage and 25 days after silking between two row spacing were significantly different. Under density of 100 050 plants/ha, root weight density and root length density were significantly different between two row spacing at the 10-leaf stage and 25 days after silking, and root weight density at three stages between two row spacing were also significant. The xylem sap volume was greater when reducing row spacing, demonstrating stronger root function, which benefit to yield formation, 6.76% and 4.89% more yield after reducing row spacing under 50 025 plants/ha and 67 500 plants/ha. Especially, significantly positive correlations existed between root traits and yield at the 10-leaf stage, showing the critical stage of root formation for high yield of summer maize.

国家“十二五”重大科技支撑计划(2011BAD16B15);“973”计划项目(2009CB118602)