Plant hydraulic resistance controls transpiration of soybean in rotational paddy fields under humid climates
Plant hydraulic resistance controls transpiration of soybean in rotational paddy fields under humid climates
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DOI：
10.1007/s10333-022-00923-5
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发表时间：
2023-01
影响因子：
2.2
通讯作者：
Shigehiro Kubota;K. Nishida;S. Yoshida
中科院分区：
文献类型：
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作者：
Shigehiro Kubota;K. Nishida;S. Yoshida
高效的灌溉和排水管理是提高水稻和高地作物轮作生产力的关键。然而，传统的管理没有充分考虑植物和根区土壤的水分状况。本研究的目的是评估是否土壤（Rs）或植物（Rp）的水力阻力主要控制位于潮湿地区的轮作稻田（RPFs）的蒸腾作用。为了实现这一目标，我们进行了田间测量的土壤水分条件，蒸散速率，和叶水势在开花期后种植的RPFs大豆和计算RsandRp的基础上的根系吸水的理论。开花期后，由于间歇性降水，土壤有时会饱和，从而使Rs维持在一个较低的值。相反，Rp随时间逐渐增加，范围在5.1 × 108 ~ 10.3 × 108 s之间，比Rs高1 ~ 3个数量级。实际蒸腾速率与潜在蒸腾速率的比值在整个调查期间都在下降，即使土壤足够湿润，也很难达到1.0。这些结果表明，Rp，这可能会增加持续土壤饱和度，控制作物蒸腾RPF在潮湿气候下。我们的研究结果表明，排水系统是必不可少的RPF，以避免在Rp的变化，提高作物生产力。
Efficient irrigation and drainage management are highly required for increasing crop productivity in paddy rice and upland crop rotation. However, conventional management does not sufficiently consider the water status of the plants and soil in the root zone. The aim of this study was to evaluate whether the hydraulic resistance of soil (Rs) or plant (Rp) principally controlled transpiration in rotational paddy fields (RPFs) located in humid regions. To achieve this, we conducted field measurements of soil water conditions, evapotranspiration rate, and leaf water potential in RPFs cropped with soybean after the flowering stage and calculatedRsandRpbased on the theory of root water uptake. After the flowering stage, the soil was sometimes saturated owing to intermittent precipitation, and thusRswas maintained at a low value. By contrast,Rpgradually increased over time and ranged between 5.1 × 108and 10.3 × 108s, which was one to three orders of magnitude higher thanRs. The ratio of the actual to the potential transpiration rate decreased throughout the investigation period and hardly reached 1.0, even though the soil was sufficiently wet. These results indicate thatRp, which probably increases with continuous soil saturation, controls crop transpiration in RPFs under humid climates. Our results suggest that drainage systems are essential in RPFs to avoid a change inRpand improve crop productivity.