Determination of Irrigation Lengths in Vertisol Soils Using the Two-Point Infiltration Method and Kostiakov-Lewis Equation

Vertisol soils, which cover large lands in irrigated areas Turkey and the world, swell when wet form deep cracks dry. These properties of soils cause a significant decrease irrigation efficiency irrigating with surface methods, thus causing water insufficiency drainage problems. If appropriate time, flow rate furrow-border lengths are used, application can be increased these soils. For this purpose, two-point infiltration tests were carried out using 120 m long, 0.5-0.6% slopping furrows. A constant level orifice was used to keep unchanged during tests. Water advanced recession times observed recorded at stations created 20 intervals. Before after test, cross-sectional area furrow measured rill-meter. By evaluating obtained data, Kostiakov-Lewis equation, is expressed as Z = 0.00822 τ 0.27695 + 0.00048 obtained. With determined optimal length estimated approximately 85 for 90% 115 80% efficiency, advance curves.