Measuring on-farm irrigation efficiency with chloride tracing under deficit irrigation.

Book Title: NA
Year Published: 2005
Month Published: NA
Author: Samani, Z. ; Sammis, T. ; Skaggs, R. ; Alkhatiri, N. ; Deras, J.
Book Group Author: NA
Abstract:

Water is a limited resource in agricultural production in arid climates. Under such conditions, high irrigation efficiency can be obtained either through implementation of efficient irrigation systems such as drip or sprinkler systems or through the age-old practice of deficit irrigation with gravity systems. The method used to increase irrigation efficiency is often dictated by economic and/or social factors. In either case, the effectiveness of water management at the farm level needs to be evaluated by measuring irrigation efficiency. The objective of this study was to evaluate the irrigation efficiencies for three crops (pecans, cotton and alfalfa) in Southern New Mexico using the chloride technique. The chloride technique is a simple method in which the natural chloride in the irrigation water is used as a tracer to estimate the leaching fraction and the irrigation efficiency at the farm level. Soil samples were collected from various fields in 15 cm increments to a depth of 180 cm at the end of the irrigation season. The samples were analysed for moisture and chloride content. In addition to the chloride technique, on-farm irrigation efficiencies were measured using applied water, yield, and water production functions. Water production functions and yields were used to estimate total evapotranspiration while flow measurements were used to calculate the amount of applied water. The results showed that high irrigation efficiency can be accomplished using deficit irrigation. Irrigation efficiency values ranged from 83 to 98%. Irrigation efficiencies using the chloride technique were compared with efficiencies estimated from direct flow measurements. The differences between the two methods ranged from 2 to 11.4%. The results showed that even though the chloride technique is subject to sampling errors and simplified theoretical assumptions, it can be used to estimate on-farm irrigation efficiency with considerable accuracy.

Pages: 555 - 559
URL: http://0-search.ebscohost.com.catalog.library.colostate.edu/login.aspx?direct=true&AuthType=cookie,ip,url,cpid&custid=s4640792&db=lah&AN=20063019757&site=ehost-live
Volume: 131
Number: 6
Journal: Journal of Irrigation and Drainage Engineering
Journal ISO: NA
Organization: NA
Publisher: NA
ISBN: NA
ISSN: 0733-9437
DOI: NA
Keywords:

accuracy, chemical composition, chlorides, cotton,efficiency, estimation, evapotranspiration, farms, fibre plants,irrigation, irrigation systems, irrigation water, leaching, lucerne,measurement, methodology, pecans, soil composition, soil water,techniques, tracers, water flow, water management, water use efficiency,yields, New Mexico, USA, Carya, Carya illinoinensis, Gossypium,Gossypium hirsutum, Medicago, Medicago sativa, Carya, Juglandaceae,Juglandales, dicotyledons, angiosperms, Spermatophyta, plants,Gossypium, Malvaceae, Malvales, Medicago, Fabaceae, Fabales, MountainStates of USA, Western States of USA, USA, North America, America,Developed Countries, OECD Countries, Great Plains States of USA,Southwestern States of USA, Horticultural Crops (FF003) (New March2000), Field Crops (FF005) (New March 2000), Forage and Fodder Crops(FF007) (New March 2000), Plant Water Relations (FF062), Soil Chemistryand Mineralogy (JJ200), Soil Physics (JJ300), Soil Water Management (Irr

Source: EBSCO
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