Soil moisture control in subirrigation open ditch system with constant depth of groundwater table
1988
Brandyk, T. (Szkola Glowna Gospodarstwa Wiejskiego - Akademia Rolnicza, Warszawa (Poland). Katedra Melioracji Rolnych i Lesnych)
An application of steady state water flow solutions of unsaturated and saturated zone for soil moisture control in subirrigation open ditch system with constant depth of groundwater table is shown in this paper. Soil moisture content of the upper layer of the root zone soil profile is dependent on the effective height of the capillary rise from the groundwater table at certain evapotranspiration rate. This height can be calculated using the numerical solution of Dracy's law for unsaturated zone. Using known value of the effective height of the capillary rise, the depth of the root zone and the minimal allowed soil moisture content in this zone, the required depth of the groundwater table in two parallel ditches can be calculated. Values of this groundwater table depth can be applied for determination of required levels in the ditches at different evapotranspiration rates using Ernst's equations as presented in this work
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