Effect of management of water consumption on vegetation development in rainwater catchment systems in arid regions

The aim of this research was to study how water use management can increases vegetation cover inrainwater catchment systems. The study was conducted through comparison of two methods of irrigation, i.e. traditional sub-surface drip irrigation and drip irrigation. Three soil samples were taken and analyzed from three locations in north of Sistan from a depth of 50 cm. A furrow was dug with a base depth of 60 cm, width of 50 cm, and  length of 48 m. 12 holds were dug 4 m long, 70 cm deep and 50 cm in diameter. For subsurface irrigation, a 3-inch pipe with a length of 48 m was placed horizontally in the furrow. At 8-m intervals, 2-mm holes were made in the pipe. In the drip irrigation method, a ½-inch pipe with a length of 48 m was placed on the furrow and drippers were connected every 8 m. In each pit, a mulberry tree was planted. Soil moisture was measured every month and growth was measured each season. Data shows that the amount moisture, increase in plant height, and trunk diameter in subsurface irrigation were 53.1, 91.6, and 52.8 percent more than drip irrigation, respectively. Statistical analyses show that soil moisture, plant height, and trunk diameter were significantly higher in subsurface irrigation (P<0.05). In subsurface irrigation, water directly flows to the root zone. Because in this method transpiration is less than drip method, subsurface irrigation has good potential to establish suitable moisture levels for plant growth.