Automatic irrigation system using soil moisture sensor

Automatic irrigation system using soil moisture sensor: a smart water management solution for modern agriculture

 INTRODUCTION

In the rapid development of modern agriculture, the effective management of water resources and the optimization of crop growth have become crucial issues. Traditional irrigation methods often rely on timed water control, which can lead to over-irrigation or under-irrigation, wasting water and affecting crop health. To meet this challenge, automatic soil moisture sensing irrigation systems have been developed, which utilize advanced sensor technology and automated control to realize the intelligence of the irrigation process, greatly improving the efficiency of water use and the production potential of crops.

 The core of the system: soil moisture sensors

The core of an automated irrigation system is the soil moisture sensor. Such sensors can accurately measure the moisture content in the soil and provide real-time feedback on the degree of wetness of the soil through the principles of electromagnetic wave, resistance change or capacitance change. For example, the NBL-S-THR series of sensors, with an accuracy of ±3%, can work stably in a temperature range of -50°C to 100°C, ensuring accurate data.

 The working principle of soil moisture sensor:

Soil moisture sensors usually have 4 main working principles:

Resistive sensor: 

by measuring the conductivity of the soil to determine the moisture content in the soil. More moisture in the soil has a better electrical conductivity, conductivity is higher.

Capacitive sensor: 

By measuring the capacitance change of the soil to deduce the moisture content. The moisture in the soil affects its dielectric constant, so soil moisture can be obtained by measuring the change in capacitance.

TDR Soil Moisture Sensor (Time Domain Reflection):

TDR utilizes the propagation properties of electromagnetic waves to measure soil moisture. The basic principle is to send a pulse signal to an electrode in the soil and measure the propagation time of the pulse signal in the soil. Since the dielectric constant (effect on electromagnetic waves) of water is greater than that of other components in the soil (such as sand or organic matter), the moisture content of the soil directly affects the propagation speed of the signal.

FDR Soil Moisture Sensors (Frequency Domain Reflectance)

FDR technology is based on the variation of the soil's dielectric constant in response to the frequency of an electromagnetic wave.FDR derives the moisture content of the soil by measuring the reflective and absorptive properties of electromagnetic waves in the soil over a specific frequency range. Different soil moisture levels change the soil's dielectric constant, which in turn affects the magnitude and phase of the frequency response.

The data from these sensors is transmitted to the irrigation system in real time, helping the system to make decisions about whether irrigation is needed.

 How Automatic Irrigation Systems Work and What They Offer

The workflow of an automatic irrigation system is simple and efficient. When soil moisture falls below a preset threshold, the sensor sends a signal to the control system, which then activates irrigation equipment, such as sprinklers or drip irrigation systems, to provide the necessary water to the crop. Once the soil moisture reaches the desired level, irrigation is automatically stopped, avoiding over-irrigation and water waste. This demand-based irrigation not only saves valuable water, but also promotes healthy crop growth, yield and quality.

 Components of an automatic irrigation system

The automatic irrigation system is mainly composed of the following components:

1. Soil Moisture Sensor: responsible for monitoring the moisture level of the soil in real time.

2. Controller: Receives data from the sensor and decides whether to start irrigation based on a preset moisture threshold.

3. Irrigation equipment: including sprinkler heads, drip irrigation pipes, etc., responsible for the actual water supply.

4. water source and pump system: provide water for the irrigation system and pressurize it through the pump to ensure the reasonable distribution of moisture.

5. Communication module: realizes data transmission between various parts of the system and supports remote monitoring and adjustment.

 Workflow

1. Real-time monitoring: the soil moisture sensor continuously monitors the soil moisture content and transmits the data to the controller.

2. Logical judgment: The controller compares the soil moisture thresholds according to the preset values and judges whether irrigation is needed.

3. Start irrigation: When the soil moisture is lower than the set threshold, the controller sends a command to the irrigation actuator to turn on the irrigation equipment.

4. Dynamic Adjustment: During the irrigation process, the sensor continues to monitor soil moisture changes, and when the soil moisture reaches the set value, the controller turns off the irrigation equipment.

5. Data transmission: The communication module transmits the system operation data to the monitoring center, so that users can view the irrigation status in real time through cell phones, computers and other terminal devices.

 Intelligent control and integration

Modern automated irrigation systems are often equipped with microcontrollers or Internet of Things (IoT) technology that can be remotely monitored and adjusted via wireless communication (e.g. LoRa or GSM networks). Users can even remotely view soil moisture status through a smartphone app and make smart adjustments based on weather forecasts and crop water requirements for precise irrigation. In addition, the system can combine weather data, soil type and crop growth stage to form a more accurate irrigation program.

 Automatic irrigation system using soil moisture sensor has a wide range of applications

From home gardens to large-scale agricultural parks, automatic irrigation systems using soil moisture sensors have demonstrated their value in a wide range of applications. Specific application scenarios include:

- Agricultural production: In large-scale agricultural fields, automatic irrigation systems can accurately control water supply according to crop demand, especially suitable for water-stressed areas.

- Horticulture and greening: City parks, flower beds, courtyards and other horticultural venues can use automatic irrigation systems for intelligent management, to ensure that plants in different seasons and climatic conditions to get the right amount of water.

- Greenhouse cultivation: In greenhouse environments, automatic irrigation systems can be combined with environmental monitoring data (such as temperature, humidity, etc.) to make intelligent adjustments to meet the water needs of different plants.

- Lawn management: Golf courses, sports fields and other lawns require regular irrigation. Automatic irrigation systems can precisely control the irrigation time and water volume to maintain the best growth condition of the lawn.

 Environmental and Economic Benefits

In the long run, automated soil moisture sensing irrigation systems offer significant environmental and economic benefits:

- Water conservation and efficiency: By monitoring soil moisture in real time, the automated irrigation system avoids over-irrigation and under-irrigation, effectively saving water.

- Improved Crop Health: Precise irrigation keeps the soil in the optimal moisture range, which helps crop roots grow and avoids plant diseases or wilting caused by over- or under-watering.

- Reduced labor costs: Automated systems reduce the need for manual operations, especially on large farms or parks, saving significant labor costs.

- Intelligent management: Users can monitor and control the irrigation system remotely via cell phone or computer, check the soil moisture, weather forecast and other data in real time, and make adjustments accordingly, which further improves the flexibility and intelligence of the system.

- Ecological balance: Reduced dependence on groundwater helps maintain ecological balance and reduce soil erosion.

 Future Outlook

With the continuous development of IoT technology, artificial intelligence and big data, automatic irrigation systems will become smarter and more efficient. In the future, soil moisture sensors will be combined with a variety of information, including weather data, soil type and crop growth stage, to form a more accurate irrigation program. In addition, the system may realize real-time interfacing with weather forecasts to predict rainfall in advance, thus avoiding unnecessary irrigation operations and further improving water-saving efficiency.

 Summary

The automatic irrigation system utilizing soil moisture sensors provides an efficient and water-saving solution for modern agricultural irrigation. It is a symbol of the progress of modern agricultural technology, which solves many problems of traditional irrigation with the power of science and technology. By precisely controlling the amount of water and irrigation time, it not only saves water, but also provides a suitable growing environment to ensure the healthy growth of crops and plants. With the continuous progress of technology and the gradual reduction of costs, this system will be more widely used worldwide, leading agriculture to a greener and smarter future.

Soil moisture sensor datasheet:

1.NBL-S-THR Soil Temperature Moisture Sensor datasheet

NBL-S-THR-Soil-temperature-and-moisture-sensors-Instruction-Manual-V4.0.pdf

2. NBL-S-TMC Soil Temperature Moisture EC Sensor datasheet

NBL-S-TMC-Soil-temperature-and-moisture-conductivity-sensor.pdf

3. NBL-S-TM Soil Temperature Moisture Sensor datasheet

NBL-S-TM-Soil-temperature-and-moisture-sensor-Instruction-Manual-4.0.pdf

4. NBL-S-TMCS Soil Temperature, Moisture, Conductivity and Salinity Integrated Sensor

NBL-S-TMCS-Soil-Temperature-Humidity-Conductivity-and-Salinity-Sensor.pdf