Low-cost Computer-Controlled Automated Irrigation System

Introduction

An automated irrigation computer control system has been developed by an Indian institute for management of irrigation. The development consisted of three distinctive steps: (1) Design of soil moisture sensor; (2) Design of suitable hardware to interface soil moisture sensors with personal computer and to control water application; (3) Development of device driver programme and a user-friendly software interface that allows easy control of the system.

The system consists of eight soil moisture sensors, a hardware input/output (interfacing circuit), a computer with a software interface and solenoid valves as actuators. The software offers options of time-based and soil moisture-based irrigation scheduling. Under the time-based irrigation scheduling there are options of operating the irrigation either at regular time intervals or at particular dates and times. Soil moisturebased irrigation scheduling consists of setting the upper and lower limits of the soil moisture content by the user. The programme reads the soil mosture status at pre-decided time intervals, also set by the user. Irrigation starts when the read soil moisture content is lower than the set lower limit of soil moisture content, and stops when the soil moisture content reaches the set upper limit of soil moisture content.

Areas of application

• For automating irrigation at small and medium size farms;
• For drip and sprinkler irrigation; and
• In greenhouses.

Advantages

• Applies precise quantity of water and nutrients, which results in higher crop yield;
• Low cost;
• Starts watering just at the right time;
• Stops watering when soil moisture attains field capacity or at any other desired level;
• Takes into account effective rainfall for scheduling irrigation;
• Saves water;
• Saves labour costs involved with manual operations;
• Precludes need to visit farm at odd times;
• Avoids leaching of minerals and nitrogen vital for plants healthy growth;
• Eliminates long-term ill effects of over-irrigation that cause salinity;
• Circuit can be interfaced to any resistance-type soil moisture sensor;
• Offers option of soil moisture-based irrigation scheduling or time-based irrigation scheduling; and
• Irrigation scheduling at large farms can be done conveniently. The circuit has been designed for scheduling irrigation at 8 plots but it can be further increased up to 64 plots.

Inputs required

Setting the upper and lower limits of soil moisture level for stopping and starting irrigation.

Raw materials

Personal computer 486 or pentium, solenoid valves, cable for connecting soil moisture sensors and solenoid valves to the computer, designed interfacing circuit, device driver programme and software for taking irrigation decisions.

Development status

Prototype

Economic data

Approximate cost INR 50,000 (US$ 1,100)

Transfer forms

Technology transfer

For further information please contact

Director
National Metallurgical Laboratory
Jamshedpur - 831007, India
Tel : 91-657-2271715, 2270092
Fax: 91-657-2270527, 2271159
E-Mail: director@nmlindia.org