نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار بخش فنی و مهندسی مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان سمنان (شاهرود)، سازمان تحقیقات، آموزش و ترویج کشاورزی، ایران
2 کارشناس، بخش تحقیقات فنی و مهندسی کشاورزی، مرکز تحقیقات و آموزش کشاورزی و منابع طبیعی استان سمنان (شاهرود)، سازمان تحقیقات، آموزش
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Subsurface drip irrigation is one of the optimal management methods of water application in the agricultural sector. The aim of this study was to investigate the technical performance and soil salinity in the subsurface drip irrigation systems in Semnan Province during the years 2019 to 2020. Five systems were evaluated in Shahroud, Damghan, and Semnan areas. For this purpose, the hydraulic characteristics of the system, soil moisture, and soil salinity were investigated. In general, the results of the evaluation showed that the coefficient of flow variations (Vqs) varied from 4% to 8%, the statistical uniformity coefficient (Us) varied from 85% to 90.7%, and the emitter discharge coefficient of variation (Vpf) varied from 0.09 to 0.15. The hydraulic performance of the systems was relatively good. The evaluation results showed, the pressure at the end of the laterals was less than necessary in some parts, but the use of pressure compensating emitters adjusted the flow in these parts. In the studied orchards, the installation depth of the laterals was non-uniform and between 15 and 45 cm. The amount of moisture increased from the soil surface to lower parts. Examination of salinity profile of soil saturated extract showed that, with increasing horizontal distance from the lateral, the amount of salinity increased, but decreased with increasing depth. The maximum amount of salinity was found in the installation depth of 30 and 40 cm, in the 0-30 and 30-60 cm soil layers. The reason for the increase in salinity in this area was the decrease in soil moisture due to the capillary rise of moisture and its evaporation from the soil surface and faster absorption of moisture by the roots. The most important factors to improve the performance of the systems are proper implementation of the systems and provision of the necessary pressure in the manifolds and laterals, soil salinity leaching in winter with heavy flood irrigation, and installation of the laterals evenly at the appropriate depth.
کلیدواژهها [English]
doi: 10.1016/j.chemosphere.2021.131300