TITLE:
Effects of Water Distribution Uniformity on Waxy Corn (Zea mays L.) Yield: Preliminary Results
AUTHORS:
Lucia Bortolini, Marco Martello
KEYWORDS:
Drip Irrigation, Sprinkler Irrigation, Profitability, Efficiency, GIS
JOURNAL NAME:
Journal of Water Resource and Protection,
Vol.6 No.11,
August
20,
2014
ABSTRACT: To face
climatic changes, the increase of frequency and severity of droughts, and
economic development pressures, Water Management Institutions point at the
necessity of water conserving. A sustainable demand-led approach is the most
viable option, focusing on achieving more efficient irrigation practices
instead of less sustainable expansion of supply. The aim of this work is to
investigate on some aspects of the rational water management for the irrigation
of corn in order to evaluate the actual possibility of introduction of drip
irrigation systems on the Venetian Plain. Trials were carried out on a farm
located in Isola della Scala (Verona, Italy) in an area of about 13 ha (12 ha
with a drip irrigation system and 1 ha with a solid-set sprinkler system); the
effects of the performance of the two systems on waxy corn yield were
considered. In particular, water distribution uniformity, water use efficiency,
and yield performance of irrigation systems were evaluated. DUlq and
CU coefficients for distribution uniformity and IWUe and WUEb indexes for water use efficiency were calculated. To visualize and better
analyze the distribution uniformity, the crop yield and the efficiency
parameters, ArcGIS 10 (ESRI?) with IDW interpolation were used to create maps.
First results show a good water uniformity distribution in the drip irrigation
system but only with a careful and proper design of the entire system. As
regards the water use efficiency, drip irrigation values are lower than those
of sprinkler irrigation (-46% for IWUe and -25% for WUEb),
probably due to different irrigation management and water volumes used: in
fact, drip irrigation was scheduled every three days, while only supplemental
operations were done for sprinkler irrigation. No statistical correlation was
found between application rate and yield for both irrigations systems, while a
significant correlation was found between irrigation volume and crop water use
efficiency. The profitability of the two irrigation systems was compared. The
results show that the income of drip irrigation is slightly lower than
sprinkler irrigation, mostly due to the use of “throw away” drip lines.