Harold R. Duke

Sensor Placement for Real Time Infiltration Parameter Evaluation

ABSTRACT THE design and operation of surface irrigation systems are significantly influenced by the infiltration rate of the field. Therefore, temporal and spatial variability of infiltration rates must be considered in the management procedures. Surge irrigation requires reliable management procedures to achieve the desirable application efficiency and uniformity coefficient under optimum cycle on and off times. A procedure is proposed to estimate the average application efficiency and uniformity coefficient of a surge irrigation event during the first advance cycle. Data from 28 adjacent furrows in an irrigation event are used to find the best location of two stations for estimation of infiltration parameters. A kinematic wave model is used with an assumed management procedure to find the average application efficiency and uniformity coefficient for the given infiltration parameters and observed surge irrigation event. Comparisons showed that the application efficiencies and uniformity coefficients predicted for station-pairs of 20 to 100 and 40 to 100 m from the inlet are in close agreement with the estimated average values. The station-pair of 20 to 40 m is the poorest choice for prediction of average application efficiency and uniformity coefficient. Increasing the number of sensors decreases the error in predictions; however the relative decrease in the average error is more significant changing from one sensor-pair to two, than from two sensor-pairs to three. Errors in predicting average application efficiency and uniformity coefficient from the poorest station-pair of 20 to 40 m with three pairs of sensors are significantly higher than with a single pair of sensor at 20 to 100 m.

‘User friendly’ software for an integrated water-energy management system for center pivot irrigation

Abstract Computers are becoming more commonly used by farmers for improving their management. The big need is ‘user friendly’ software for use by farmers. An integrated water-energy management system was developed. It includes ‘user friendly’ software run on a microcomputer which communicates to center pivot irrigation systems via radio. The program provides monitoring, control, irrigation scheduling and electrical load control. The system has been used and accepted by our cooperator for three irrigation seasons. He has been able to improve his management and reduce the amount of overirrigation and the variation between systems of total water applied.

Integrated Water-Energy Management System for Center Pivot Irrigation: Implementation

ABSTRACT AN integrated water-energy management system providing monitoring, pump control, irrigation schedules, and load control for 15 center pivots is described. The logic for establishing priorities for power interruption based on soils, crops, and irrigation systems is presented. An example showing how this system interfaces with the power suppliers existing load control equipment and interruption sequence is given.

Computer Control of Irrigation for Electrical Load Management

ABSTRACT MANY electrical power suppliers have initiated load shedding programs to reduce the operating load on the transmission and delivery system during periods of peak demand. Typically, these programs result in irrigation pump shutoff on a predetermined rotational schedule. A computerized radio telemetry system was developed which automatically determines the soil water status of the field served by each pump based on climatic data, sets priorities for load interruption based on soil water status, and stops pumps upon receipt of a signal from the power supplier. The system also provides for remote control of pumps and monitoring of their operational status.

Integrated Water-Energy Management System for Center Pivot Irrigation: Functional Requirements

ABSTRACT AN integrated water-energy management system utilizing a microcomputer and radio telemetry system for pump monitoring, pump control, irrigation scheduling and electric load control is described. This system collects, processes and stores pump operation and weather data automatically yet allows the operator real time control of individual pumps. The sequencing of the various tasks between automatic data collection and real time control is explained. The various interactive tasks available to the operator for manual control and monitoring are described.