The effect of combined engineering structure on reducing water use of Eucalyptus plantations in Sistan plain

Combating wind erosion is one of the functions of vegetation in environments prone to this type of erosion. But vegetation establishment in such places is limited. In such a situation, the use of physical protection methods like plastic pipe is required to plant trees. The aim of research is to find out the scientific method to re-establish the vegetation cover and desert prevention with low-water-using in dry land regions. In order to conduct the research, 20 holes, 80 cm in diameter and 120 cm in depth were drilled and Eucalyptus seedlings were planted inside them. Inside plastic tubes with a diameter of 15 and a length of 80 cm, 10 seedlings were placed, so that they were 50 cm high and 30 cm inside the soil. The irrigation time was determined using the Time-domain reflectometry, TDR, and the seedlings were irrigated. Seedling height, crown cover and water were measured monthly. 18 soil samples were taken from three plots and six depths, and some of their characteristics were measured. Dates were analyzed using SPSS software. The statistical analysis showed that there is no significant difference between the canopy cover of the two treatments, but there are significant differences between the height, biomass and water consumption of seedlings at the level of 0.01. In addition, biomass index for seedlings of these treatments was estimated to be 1.5 and 6.3, respectively. In order to grow a square meter of canopy and one meter height seedling in treatment with tube, 505 and 132.7 liters of water are required, while for tubeless treatment, they are 1422.22 and 471.2 liters, respectively.