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Authors
Advisor(s)
Abstract(s)
This study aims at assessing the feasibility of deficit irrigation of maize, wheat and
sunflower through an analysis of the economic water productivity (EWP). It focuses on
selected sprinkler-irrigated fields in Vigia Irrigation District, Southern Portugal. Various
scenarios of water deficits and water availability were considered. Simulations were performed
for average, high and very high climatic demand. The potential crop yields were
estimated from regional climatic data and local information. Using field collected data on
yield values, production costs, water costs, commodity prices and irrigation performance,
indicators on EWP were calculated. Results show that a main bottleneck for adopting
deficit irrigation is the presently low performance of the irrigation systems used in the
considered fields, which leads to high water use and low EWP. Decreasing water use
through deficit irrigation also decreases the EWP. Limited water deficits for maize are likely
to be viable when the irrigation performance is improved if water prices do not increase
much, and the commodity price does not return to former low levels. The sunflower crop,
despite lower sensitivity to water deficits than maize, does not appear to be a viable
solution to replace maize when water restrictions are high; however it becomes an
attractive crop if recently high commodity prices are maintained. With improved irrigation
performance, wheat deficit irrigation is viable including when full water costs are applied,
if former low prices are not returned to. However, under drought conditions full water
costs are excessive. Thus, adopting deficit irrigation requires not only an appropriate irrigation
scheduling but higher irrigation performance, and that the application of a water
prices policy would be flexible, thus favouring the improvement of the irrigation systems.
Description
Research Paper:SW-Soil and Water
Keywords
deficit irrigation water produtivity water costs economic impact
Pedagogical Context
Citation
"Biosystems Engineering". ISSN 1537-5110. 103(2009) 536-551