HYDRUS simulations of the effects of dual-drip subsurface irrigation and a physical barrier on water movement and solute transport in soils

Subsurface drip irrigation systems, compared to other irrigation systems, enhance the delivery of water and nutrients directly into the root zone. However, in light-textured soils, certain quantities of water may percolate below the root zone due to the subsurface position of drip lines and/or poor management of irrigation systems. The main objective of this paper is to evaluate three technologies to enhance a spatial distribution of water and solutes in the root zone and to limit downward leaching. The three technologies include (a) a physical barrier, (b) a dual-drip system with concurrent irrigation, and (c) a dual-drip system with sequential irrigation. To achieve this objective, we performed computer simulations using the HYDRUS (2D/3D) software for both bare and vegetated soils. The results indicate that the physical barrier is more efficient than dual-drip systems in enhancing the water distribution in the root zone while preventing downward leaching. On the other hand, the dual-drip system improves water distribution in sandy soils. Additionally, the dual-drip system with sequential irrigation, followed by the dual-drip system with concurrent irrigation, is the most efficient in limiting downward leaching of solutes. © 2013 Springer-Verlag Berlin Heidelberg

HYDRUS simulations of the effects of dual-drip subsurface irrigation and a physical barrier on water movement and solute transport in soils

Subsurface drip irrigation systems, compared to other irrigation systems, enhance the delivery of water and nutrients directly into the root zone. However, in light-textured soils, certain quantities of water may percolate below the root zone due to the subsurface position of drip lines and/or poor management of irrigation systems. The main objective of this paper is to evaluate three technologies to enhance a spatial distribution of water and solutes in the root zone and to limit downward leaching. The three technologies include (a) a physical barrier, (b) a dual-drip system with concurrent irrigation, and (c) a dual-drip system with sequential irrigation. To achieve this objective, we performed computer simulations using the HYDRUS (2D/3D) software for both bare and vegetated soils. The results indicate that the physical barrier is more efficient than dual-drip systems in enhancing the water distribution in the root zone while preventing downward leaching. On the other hand, the dual-drip system improves water distribution in sandy soils. Additionally, the dual-drip system with sequential irrigation, followed by the dual-drip system with concurrent irrigation, is the most efficient in limiting downward leaching of solutes. © 2013 Springer-Verlag Berlin Heidelberg

Harvesting water in a center pivot irrigation system: Evaluation of distribution uniformity with varying operating parameters

The main objective of irrigation is to apply the optimum amount of water to the crop root zone that is needed for its growth. Also, when irrigation systems are used to apply fertilizers and pesticides, the irrigation process becomes even more critical in terms of uniformity. Consequently, it is important for center pivot owners and operators to periodically check the uniformity of their systems in order to adjust all the operating parameters involved. To assess the real distribution uniformity of irrigated water, a study was conducted in southern Libya; this paper reports the results of water irrigation in a center pivot system with respect to the effects that the operating pressure (P), the spacing between sprinklers (S), and the height of sprinkler above the ground surface (H) show on the distribution uniformity. Several factors define the uniformity of water distribution; in this work the coefficient of uniformity CU, the low quarter distribution uniformity DUlq, and the coefficient of variation CV are considered. The highest values reached by the uniformity parameters with varying the operating conditions define the best operating practices under which the whole system works efficiently. The final results are given in terms of operating conditions able to save total costs in the studied area and in places characterized by similar geo-hydrological conditions