Automatic Plant Watering and Irrigation Systems

Automatic Plant Watering and Irrigation Systems . Gardening has always been a blend of art and science, requiring meticulous care and attention to keep plants thriving. With the advent of technology, the introduction of the automatic plant watering and irrigation system has revolutionized the way plants are nurtured.

An automatic irrigation system is a device that delivers water to plants efficiently and consistently without requiring manual intervention. These systems are especially crucial in modern gardening and farming, where water conservation and plant health are top priorities.

How It Works

Sensors and Controllers in Automatic Systems

Automatic watering systems rely on advanced sensors and controllers. These devices monitor soil moisture levels, weather conditions, and plant needs to determine when and how much water to dispense.

Types of Irrigation Methods Used

Drip Irrigation: Delivers water directly to plant roots, minimizing evaporation.
Sprinkler Systems: Simulates rainfall to cover a wide area.
Surface Irrigation: Floods the soil evenly across a garden plot.

Types of Automatic Watering Systems

Pneumatic system

A pneumatic system is a permanent system activated by a bay sensor located at the cut-off point. When water enters the sensor, it pressurises the air, which is piped to a mechanism that activates the opening and closing of irrigation structures.

Portable timer system

A portable timer system is a temporary system which uses electronic clocks to activate the opening and closing of the irrigation structures. Because of its portable nature, 4 or 5 units are usually purchased to move around the whole property.

Timer or sensor hybrid

As the name suggests, this system is a hybrid of portable timer and sensor systems.

Like a portable timer, it uses an electronic device to activate the opening and closing irrigation structures.

This system has an additional feature of the irrigator being able to place a moveable sensor down the bay. When it comes in contact with water, it transmits radio signals to the timer devices at the outlets to open or close the structures. It then sends a radio message to a receiver to let the landowner know water has reached the cut-off points down the bay.

Supervisory Control and Data Acquisition (SCADA)

Automation systems that use SCADA consist of a personal computer and software package to schedule and control irrigation via a radio link.

Signals are sent from the computer to control modules in the paddock to open and close irrigation structures with linear actuators.

Bays are opened and closed on a time basis. Some systems have the capacity to automatically alter the time a bay outlet is open, if the channel supply is inconsistent.

SCADA based systems have the additional benefit of being able to start and stop irrigation pumps and motors.

Automating an irrigation layout

An irrigation layout can be automated at one of two places — in sections of channel or at individual bay outlets.

Automation of channel sections

In this system, the channel structures are automated, allowing the channel level to be changed. The bay outlets do not have opening or closing structures. Moreover, each set of outlets is set at a specific level (such as a set of sills).

This method of automation requires a larger amount of fall to be available in the channel system to allow for a change in water level between different areas.

This change in water level is required to prevent water flowing onto bays previously irrigated, when another section is to be irrigated.

On many farms, this fall is not available, so this method of automation in many cases is not suitable.

Automation of individual bay outlets

This method of automation involves control of the bay outlets to change the flow of water onto the areas being irrigated.

This system of automation is the most frequently used in areas where there is insufficient fall to automate channel sections.

The same type of automatic devices available can be set up to operate either automation of channel sections or automation of bay outlets.

Automatic Plant Watering System using Arduino

During summer, most people are too lazy to water the potted plants on their rooftop gardens every day. So, we build a simple and exciting automatic plant watering system that you can build yourself in just a few hours.

It is an Arduino based automatic plant watering system that uses a soil moisture sensor. The author’s prototype is shown in Fig. 1.

Components Required

Soil Moisture Sensor

Two types of soil moisture sensors are available in the market—contact and non-contact sensors. A contact soil sensor is used in this project because it has to check soil moisture to measure electrical conductivity.

Automatic Plant Watering System circuit

The circuit diagram of the automatic plant watering system is shown in Fig. 2. The circuit comprises an Arduino UNO board, a soil moisture sensor, a servo motor, a 12V water pump, and an L293D (IC1) motor driver IC to run the water pump.

You can power the Arduino board using a 7V to 12V wall wart or plug-in adaptor or solar panel. You need a separate 12V battery or power supply or solar panel for the pump motor.

The moisture sensor provides an analog output, which can easily be interfaced with Arduino. In this project, two sensors can be connected to analog pins, A0 and A1 of the Arduino board. Each sensor has four pins (Vcc, Gnd, Ao, and Do) available for interfacing with the Arduino board.

Here, a digital output pin (Do) is not used. The water pump and servo motor are controlled by Arduino connected to digital pins 3 and 9, respectively. That is, the servo motor signal control pin is connected to pin 9 of the Arduino board.

Fig. 2 Circuit diagram of the automatic plant watering system

The program in the Arduino reads the moisture value from the sensor every 20 seconds. If the value reaches the threshold value, the program does the following three things:

It moves the servo motor horn, along with the water pipe fixed on it, toward the potted plant, whose moisture level is less than the predetermined/ threshold level.
It starts the motor pump to supply water to the plant for a fixed period of time and then stops the water pump.
It brings back the servo motor horn to its initial position.

Automatic Plant Watering System – Code

The program is written in Arduino programming language. The code is well-commented and easy to understand. Compile the autowatering.ino code and upload it to the microcontroller, using Arduino IDE version 1.

The sensor will calibrate by itself once it is kept in the soil and the threshold value will be shown on the serial monitor in Arduino. Serial debugging is available in this program. Comment out if you do not wish to use the serial monitor.

Download Source Code

PCB Design

An actual-size, single-sided PCB layout of the automatic plant watering system is shown in Fig. 3, and its component layout is in Fig. 4.

Assemble the components on the PCB to minimize errors. Alternatively, you can assemble them on a breadboard or Arduino prototyping shield, or a general-purpose PCB. Upload the code to the Arduino UNO board and install the sensors in the soil of the potted plants. Do not immerse the sensors fully inside the soil.

Download PCB and Component Layout

Advantages of Automatic Systems

Water Efficiency

Automated systems use sensors to provide water only when necessary, cutting down water wastage significantly.

Time Savings

For busy individuals, these systems are a game changer, eliminating the need for daily manual watering.

Consistent Plant Health

Plants thrive when they receive consistent watering. Automated systems ensure uniformity, promoting healthier growth.

Key Components of an Automatic Plant Watering System

Moisture Sensors

These sensors measure soil moisture levels and send signals to the controller to activate or stop irrigation.

Control Valves and Timers

Valves regulate the flow of water, while timers ensure irrigation occurs at optimal times of the day.

Irrigation Pipes

Pipes are essential for distributing water to all parts of the garden efficiently.

Read More : Infrared Motion Detector Circuit

How to Choose the Right System

Factors to Consider

Garden Size: Larger areas may require sprinklers, while small gardens benefit from drip systems.
Plant Types: Different plants have unique watering needs.
Budget: High-end systems offer advanced features but cost more upfront.

Matching System to Garden Needs

Evaluate the layout of your garden and select a system that aligns with the plant arrangement and irrigation requirements.

Benefits of Automatic Plant Watering and Irrigation Systems

Step-by-Step Installation Guide

Tools Required

Spade
Irrigation pipes
Timer and controller
Moisture sensors

DIY Installation Steps

Plan the Layout: Identify areas requiring irrigation.
Install Sensors and Pipes: Place moisture sensors strategically and lay pipes accordingly.
Connect the Controller: Set up the controller to manage timing and water flow.
Test the System: Run a test to ensure even water distribution.

Cost Analysis

Initial Investment

Depending on the system type, the initial cost may range from $100 to $1,000.

Maintenance Costs

Regular maintenance, such as cleaning clogged pipes and replacing sensors, is essential but cost-effective in the long run.

Long-Term Savings

The water savings achieved can significantly reduce monthly utility bills, making the system a worthwhile investment.

Common Challenges and Solutions

Dealing with Clogging

Filters can prevent debris from entering pipes and causing blockages. Regular cleaning helps too.

Adjusting for Seasonal Changes

Update the system’s settings during different seasons to match varying water needs.