THE EFFECT OF THREE DEPTHS OF SUBSURFACE DRIP IRRIGATION LEVELS WITH TWO TYPES OF SOIL ON THE PERCENTAGE OF SOIL MOISTURE CONTENT

The experiment was carried out in the educational nursery field of Department of Plant Production Technologies / Mosul Technical Institute during the agricultural season 2019-2020, to study two factors; the first is studying the effect of three depths, 5 cm (T1), 10 cm (T2) and 15 cm (T3), using Subsurface Drip Irrigation (SDI) The second factor is studying two types of sandy and silty loam soil on the soil moisture content and on some characteristics of the vegetative growth and yield of radish plants. The results show that the best depth of subsurface irrigation pipes was at treatment T3 (15 cm), where the highest values of moisture content at treatment T3, and the percentage of increase of the humidity before and after irrigation when the treatment (T1, T2, T3) is (10%, 12%, 16.3%) for the silty loam soil. As for sandy soils, it is shown that the percentage increase of moisture before and after irrigation when the treatment (T1, T2, T3) is ( 11.6%, 16%, 22.9%); meaning that the highest increase of moisture content is at Treatment T3, and this is due to evaporation from the ground surface decreases as the depth of wet soil increases, as well as the depth of i 5 cm provides a direct connection of water to the plant root area, and the results show that the best depth is for subsurface irrigation pipes 15 cm, i.e. treatment T3 in terms root weight and diameter root, plant height, leaves number, and total 'yield.