Soil water dynamics under Moistube irrigation

Publication date: Available online 11 January 2020Source: Physics and Chemistry of the Earth, Parts A/B/CAuthor(s): Edwin Kimutai Kanda, Aidan Senzanje, Tafadzwanashe MabhaudhiAbstractThe design and management of irrigation systems require knowledge of soil water movement. There are few studies on soil water dynamics of Moistube irrigation (MTI) since it is a relatively new type of subsurface irrigation technology. It was hypothesised that soil texture influences soil water distribution under MTI. We determined soil water distribution, experimentally and numerically, using HYDRUS 2D/3D model for two soil textures (loamy sand and sandy clay loam). The experiment consisted of a soil box filled with soil and Moistube, supplied with water under a constant pressure head of 60 kPa, placed at 20 cm below the top of the soil surface. Soil water content (SWC) was measured using Decagon MPS-2 sensors installed at depths of 5 cm, 10 cm, 15 cm, 20 cm, 30 cm, 40 cm and 50 cm and laterally at 10 cm, 20 cm and 30 cm over a period of 72 h. Results showed that simulated SWC closely matched (R2 ≥ 0.70 and RMSE ≤ 0.045 cm3 cm−3) observed values for all depths considered for the two soil textures. The model slightly under- or over-estimated SWC (<15.6%). There was no significant difference (p > 0.05) between the soil water distribution in lateral and downward direction for both sandy clay loam soil and loamy sand. However, the SWC upward of the...
Source: Physics and Chemistry of the Earth, Parts ABC - Category: Science Source Type: research