Abstract:
Drip irrigation, even though may be considered one of the most efficient irrigation method today, still allows relatively high evaporation from the saturated zone that develops under emitters especially in soils of low infiltration rates. Initial lateral water movement may take a long time in such soils thus exposing surface water to high evaporation. A vertical gravel tube, installed in the soil beneath the emitter, will induce vertical water infiltration keeping the actual water surface deeper in the soil profile. The objectives of this research was to study the effect of gravel vertical mulching (GVM) on the distribution of water in the root zone and the potential for water saving. A field experiment was conducted, at the Agricultural Research and Education Center (AREC), to meet the stated objectives. Two factors were studied; (A) Level of irrigation (100, 70, and 40percent of the total water requirement of the trees) and (B) Gravel mulch in two levels (gravel and no-gravel). The 2 X 3 treatments were randomized over nine trees in three replicates, and soil moisture content was measured at 1, 7, and 14 days after each of two irrigations. Measurements were taken at 3 distances and 4 depths from each dripper. The results indicated that the irrigation level has a significant effect on water storage at deeper soil layers, whereas the gravel mulch was effective in increasing soil water content at the 20-50cm depth and becomes insignificant at deeper layers. Over time, as the soil is drying up, the significance of the gravel factor increases. Considering the root zone profile as a whole, the Graveled plots had higher water content than the Non-Graveled plots. © ISHS.