Energy Reduction and Uniformity of Low-Pressure Online Drip Irrigation Emitters in Field Tests

Julia Sokol,Abdelaziz Bouizgaren,Elizabeth Brownell,Rachid Moussadek,Gianni Montanaro,Naem Mazahrih,Khaled Abu Naser,Amos G Winter,Susan Amrose,Abdeljabar Bahri,Khalil Bany Mustafa,Samer Talozi,Bassou Bouazzama,Vinay Nangia,Lhassane Sikaoui

doi:10.3390/w11061195

Abstract

A promising way of addressing the issue of growing water scarcity is through wider use of drip irrigation, which delivers water and fertilizer to crops in a slow, targeted manner, and has been shown to increase yields and water use efficiency. Yet, drip irrigation system adoption is low, primarily due to the high capital cost of the pressurized piping network and the pump, and operating energy cost. Lowering the water pressure needed for drip emitters to deliver water can reduce both capital and operating costs of drip systems. Here we present the results from field trials of new pressure-compensating online drip emitters that operate with a minimum compensating inlet pressure of 15 kPa (0.15 bar), in comparison to typical commercial emitters with minimum pressures of 50–100 kPa (0.5–1.0 bar). The field trials were carried out on nine farms in Morocco and Jordan over the course of one irrigation season with freshwater and treated wastewater. Low-pressure emitters are shown to reduce hydraulic energy per unit volume of water delivered by 43% on average compared to commercial emitters, without significantly sacrificing water emission uniformity (low-pressure emitters show uniformities of 81–91%, compared to 87–96% for commercial emitters). This energy reduction could lead to savings of 22–31% in the capital cost of a pump and emitters and the energy cost for a typical drip irrigation system. Thus, the low-pressure online emitters can be used as substitutes to commercial emitters that require higher water pressures, leading to reduced environmental impact and lower system costs.

Highlights

Rising global water scarcity is limiting the growth of agricultural productivity, especially in arid regions [1]
Due to the differences in the number of irrigation events that passed these criteria at each plot, the hydraulic energy results are normalized by the volume of water delivered to the plot (Equation (4))
In order to translate the savings in hydraulic energy due to the use of low-pressure emitters, as reported in Section 3.1, into pumping energy cost savings that a farmer might experience, the hydraulic reported in Section 3.1, into pumping energy cost savings that a farmer might experience, the energy needs to be divided by the efficiency of the pump supplying the water

Summary

Introduction

Rising global water scarcity is limiting the growth of agricultural productivity, especially in arid regions [1]. PEER REVIEW of 28 pipes with emitters laid out along rows of crops, reducing water lost to evaporation and deep percolation. It allows greater control over the rate and amount of water and fertilizer application and enables water-saving water-saving and and yield-increasing yield-increasing strategies strategies such such as as deficit deficit or or supplemental supplemental irrigation. When best practices practices are are applied, applied, drip drip irrigation irrigation has has been been shown best shown to to reduce reduce water water use use by by 9–70%. 8–50% compared compared to to flood flood irrigation irrigation [2,3,4,5]. [2,3,4,5]. crop

Results

Discussion

Conclusion