Uptake of water from a Kandosol subsoil: I. Determination of soil water diffusivity
Uptake of water from a Kandosol subsoil: I. Determination of soil water diffusivity
复制标题
DOI：
10.1007/s11104-012-1525-8
复制
发表时间：
2013-07-01
期刊：
影响因子：
4.9
通讯作者：
Katupitiya, Asitha
中科院分区：
文献类型：
--
作者：
Deery, David M.;Passioura, John B.;Katupitiya, Asitha
目的 确定中低含水量（吸力范围为 10 至 150 m 水）的原状田间土壤的土壤水分扩散系数 D(theta)，以模拟植物根系对水分的吸收。 方法 该方法基于对土芯暴露端上方干燥空气湍流引起的一步流出的分析，而芯的另一端则封闭。流出量是随着时间的推移测量的，即核心位于记录天平上时的重量变化。 D(theta) 通过对测得的流出函数进行解卷积来计算。结果 在 10 至 150 m 水的吸力范围内，对原状土壤计算的 D(theta) 范围为 20x10(-9) 至 10x10(-9) [m(2)s(-1)]，远高于其他已发表的在此吸力范围内的估计值。结论 这些异常大的值使人们对水流根部限制从目标底土中吸收水分。
Aims To determine soil water diffusivity, D(theta), on undisturbed field soil at medium to low water content (suction range from 10 to 150 m of water), for the purpose of modeling the uptake of water by plant roots.Methods The method is based on the analysis of one-step outflow induced by a turbulent stream of dry air over the exposed end of a soil core, with the other end of the core enclosed. The outflow is measured through time as the change in the weight of the core as it sits on a recording balance. D(theta) is calculated by deconvoluting the measured outflow function.Results Over the suction range of 10 to 150 m of water, D(theta) calculated on the undisturbed soil ranged from 20x10(-9) to 10x10(-9) [m(2)s(-1)], substantially higher than other published estimates over this range in suction.Conclusions These unusually large values cast doubt on the view that flow of water to roots limits uptake of water from the targeted subsoil.