通过玉米品种"郑单958"与"沈单16号"分别在两种密度(45 000株·hm-2, 60 000株·hm-2)下隔行间作试验, 测定了不同生育期玉米茎流速率及根系导水率, 结合生育期蒸腾水量和耗水量变化特征, 分析了不同的品种间作模式对玉米水分平衡的影响。结果表明: 两品种不同密度间作可以提高玉米的根系导水率和根系活力, 延长功能期, 且不同间作处理下, 高密度品种根系导水率提高明显; 不同品种茎流速率随其间作密度的提高呈增加趋势, 且高密度间作品种日变化曲线呈"M"型, 低密度为单峰曲线, 间作下高密度品种茎流速率的最大值较早出现; 各生育期内, 高密度间作品种的蒸腾量高于低密度间作品种, 高密度间作品种最大日蒸腾量出现在灌浆期和蜡熟期, 低密度则出现在抽雄期和乳熟期。水分利用效率(WUE)呈现低密度单作<间作<高密度单作, 主要受产量的影响。不同品种间作可以有效改善玉米的根系吸水能力, 延长根系功能活性; 间作可提高WUE, 但效果不显著, 这与间作品种组合和密度水平有关。
Water transport is a fundamental aspect of crop physiology and an active area of research. Also water budget research under different maize cultivation patterns has been largely inadequate, especially on the area of maize cultivars intercropping and water balance. To determine the impacts of maize cultivars intercropping on plant-level water balance, "Zhengdan958" and "Shendan16" maize cultivars were planted in inter-lacing rows at two different inter-planting densities (45 000 plants·hm-2 and 60 000 plants·hm-2) in a total of four treatments. Grain yield, soil water content, stem sap flow (SSF) and root water conductivity (RHC) at different growth stages were investigated. The combined effects were analyzed for different characteristics of plant water consumption and transpiration. This enabled the efficient analysis of all the relevant factors of plant water transport. The results showed that intercropping improved root water conductivity, enhanced root water absorption vigor and functional continuity. Just as RHC, SSF obviously increased with increasing intercrop density. Daily variations in SSF followed an M-shaped curve under high density, but inverted a V-shaped curve under low density. Because of interplant density, maximum SSF appeared earlier in high than in low density treatments. Based on the changes in RHC and SSF, daily plant transpiration was extremely higher in high than low density plants. The maximum transpiration value for high-density plants occurred at grain filling and waxing stages. It occurred at tasseling and milking stages in low-density plants. Consequently, water use efficiency (WUE) was in the order of: low-density monoculture < intercropping < high-density monoculture. The above sequence was directly driven by yield differences. Cultivar intercropping improved root water absorption, extended root vigor and enhanced WUE. However, WUE distinctly varied with cultivar type and intercropping density. Further research was needed to build more understanding into these plant processes.