cotton - Greenmount Press

Irrigation
feature…
Adaptive control
to improve
surface irrigation
efficiency
THERE are potential water use efficiency improvements
in surface irrigation through the use of automation and
control systems to account for spatial variability of water
requirements within the field.
It is envisaged that this technology will lead to a fully
automated irrigation decision-making and control system. This
will involve soil and crop sensors that can be mounted on onfarm
vehicles to collect data while spraying or tilling. Data from
these sensors feed into the control strategy which determines
the irrigation application and/or timing. This control strategy then
automatically sends control actions to control valves into each
furrow or group of furrows to start, end or adjust the irrigation
application.
Research conducted by Dr Alison McCarthy of the National
Centre for Engineering in Agriculture (NCEA), a research centre
within the University of Southern Queensland, is evaluating
adaptive control systems for surface irrigation systems, and
providing a step towards a fully automated irrigation system.
“My research demonstrates that irrigation requirements may
be determined using adaptive control and provides potential for
yield and water use improvements,” Alison said.
The research is funded by the Cotton Research and
Development Corporation. The aim of this research is to
account for the spatial variability of irrigation requirements
across the field. This has been achieved using control systems
that determine site-specific irrigation application. These control
systems require:
■ Infield soil and plant measurements;
■ Real-time advance rate data;
■ A control strategy to determine irrigation application and/or
timing; and,
■ Actuator hardware to adjust irrigation application.
A crop model-based control strategy was applied to surface
irrigation in a field experiment in 2011–12. This involved:
■ Calibrating a crop production model (OzCOT) using the
available weather, soil and plant data;
■ Using the crop model to predict the irrigation timing and/or
volume that produces the desired performance; and,
■ Using the surface irrigation model SISCO to determine
the irrigation flow rate and advance trajectory that best
corresponds to the optimal irrigation distribution.
Flow meters and controllable valves that receive control
signals to adjust flow rate or stop irrigation.
Plant sensing apparatus under shroud.
Precision Irrigation Made Easy
CENTRE PIVOT and
LATERAL MOVE IRRIGATION
24 — The Australian Cottongrower December 2012–January 2013