Smart agriculture and advanced sensor-based systems can optimize agricultural processes, improve decision-making, and increase efficiency in water management and crop cultivation. 

The number of people on the planet is growing at an accelerated rate, and this increases the demand for food. Only by focusing on the agriculture sector would it be possible to produce enough food and meet each person's basic needs. 

Any country must prioritize agriculture as a key economic sector. Smart agriculture (SA) is an important and more popular topic in the current scenario for all countries. 

What is the role of the Internet of Things and wireless sensor networks?

Enhancing food production in a variety of agricultural domains, such as irrigation, soil moisture monitoring, fertilizer optimization and control, early-stage pest and crop disease management, and energy conservation, requires integrating the Internet of Things (IoT) and Wireless Sensor Networks (WSNs). 

Automation in agriculture should therefore be integrated and changed from conventional to SA. The IoT-WSN widely used in irrigation systems in smart agriculture applications is discussed in detail in this article.

Role of Sensors in Irrigation System

A scientific field called Smart Irrigation Systems (SIS) uses data-intensive methods to increase agricultural yield while minimizing environmental effects. With the help of various sensors, advanced agricultural processes provide data that improves awareness of activities and operational conditions. 

It enables extremely precise and effective decision-making. The SIS is a new method that conserves water and enhances performance by automating irrigation systems. 

With the help of recently implemented topologies that conserve water for irrigation, farmers can meet their needs by adapting irrigation according to the soil and weather conditions. To achieve this facility, the irrigation system uses wireless network protocols and WSN. 

A few of the proposed topologies are discussed in detail in this article.

Raspberry Pi 4B SBC-Based System

Researchers have proposed an inventive IoT-based prototype system for precision crop irrigation. This system utilizes microprocessors and a single-board computer (SBC) to gather sensor data. 

This system monitors critical soil factors, including:

  • Temperature
  • Humidity
  • UV light
  • Moisture

One noteworthy characteristic is the Raspberry devices' powerful 4-core CPUs running at 1.5GHz (Fig. 1), which highlights their computational efficiency when compared to the Arduino UNO's 16MHz operation. 

Fig. 1 Raspberry Pi 4. Source: raspberry.com

The system incorporates several sensors, such as:

  • DHT22 sensor for temperature and humidity measurements in the air 
  • VEML6070 UV sensor for tracking UV radiation and its impact on crop growth
  • Capacitive soil moisture sensors. 

An Arduino MEGA 2560 R3 microcontroller module is linked to the sensors. A Raspberry Pi 4B SBC receives the data wirelessly from the sensors attached to the Arduino. The Raspberry Pi 4B 11 is the newest computer in the well-known Raspberry Pi line. The XBee Zigbee S2 2mW (ZigBee Mesh) is the wireless module. 

This work makes a significant contribution to water management applications and agricultural technologies.

Arduino Pro-Mini Microcontroller-Based System

Researchers suggested wireless soil moisture sensors with low energy consumption and affordability, making them feasible from a technological and financial standpoint. 

This sensor is unique in that it uses a single parameter to precisely calibrate itself, allowing continuous tracking of irrigation water demand. Significant issues with water use efficiency were successfully addressed since it was purposefully created to adapt to the unique needs of water consumers and was effectively implemented inside an irrigation plan in Tunisia. 

The proposed topology comprises of:

  • The Pilowtech sensor
  • The capacitance soil moisture sensor, model EK1940 v1.2 
  • The microcontroller used is Arduino Pro-Mini (Fig. 2)
  • LoRaWAN (Long-Range Wide-Area Network) communication protocol (LoRa SX1276 communication module)
  • Rechargeable Li-ion 18,650 battery (3.7 V and 3500 mAh).

Fig. 2 Arduino Pro Mini. Source: ardunio.cc

Throughout a growing season, they tested the WSN on pilot plots and compared its results to those of commercial sensors to evaluate the sensor. Notably, communication inside the network was accomplished using the skilled application of Wi-Fi technology. 

Additionally, the authors offered insightful advice by supporting the use of these reasonably priced sensors as a key instrument for enhancing water resource management and for current-time irrigation monitoring.

ESP32-LoRa Microcontroller-Based System

Researchers proposed a cost-effective cloud-based irrigation system. It is dependent on the SigFox network for internet connectivity and the WSN-based microcontroller ESP32-LoRa. 

The outcomes confirm the resilience and stability of the system. This system was equipped with multiple sensors that measured a range of irrigation parameters, including soil and air variables like:

  • pH
  • Temperature
  • Humidity
  • Matric potential
  • Irradiance
  • Wind speed 
  • Precipitation

The study proved the efficacy of an Internet of Things-based irrigation control and management system that is appropriate for a variety of agricultural environments. The use of affordable SigFox technology addresses the issues of connectivity and energy availability for SA systems in rural areas.

ESP32 MCU-Based System

Researchers developed an Internet of Things system to assist farmers in estimating the quantity of water they will need for irrigation. This novel system uses sensors to measure temperature and moisture in the soil. 

The data it collects is then sent to the LoRaWAN system, which includes the computation of evapotranspiration. Cropwat software is utilized to determine global evapotranspiration, and analysis of the sensor data allows for accurate estimates that are customized to microclimate circumstances. 

Fig. 3 ESP32 development kit. Source: espressif.com

The ESP32 MCU, as shown in Fig. 3, was selected with built-in Wi-Fi connectivity, which guarantees a constant internet gateway connection and allows data to stream smoothly into application layer services. This method greatly improves the efficiency of data gathering and transmission.

Summarizing the Key Points

  •  Integration of IoT and WSN technologies enhances precision agriculture practices, optimizing irrigation and resource management.
  • Smart farming systems enable real-time monitoring of soil conditions, leading to improved crop yield and water efficiency.
  • Cost-effective sensor networks offer sustainable solutions for irrigation control and management in diverse agricultural settings.
  • The utilization of advanced sensors and cloud-based systems revolutionizes agricultural practices, promoting data-driven decision-making.
  • Adoption of IoT-based systems facilitates customized irrigation strategies, promotes sustainable water usage and enhances crop productivity.

Reference

Mowla, M. N., Mowla, N., Shah, A. F. M. S., Rabie, K. M., & Shongwe, T. (2023). Internet of Things and Wireless Sensor Networks for Smart Agriculture Applications: A Survey. IEEE Access, 11, 145813–145852. https://doi.org/10.1109/access.2023.3346299

Routis, G., & Roussaki, I. (2023, October). Low Power IoT Electronics in Precision Irrigation. Smart Agricultural Technology, 5, 100310.
https://doi.org/10.1016/j.atech.2023.100310

Vandôme, P., Leauthaud, C., Moinard, S., Sainlez, O., Mekki, I., Zairi, A., & Belaud, G. (2023, August). Making technological innovations accessible to agricultural water management: Design of a low-cost wireless sensor network for drip irrigation monitoring in Tunisia. Smart Agricultural Technology, 4, 100227. https://doi.org/10.1016/j.atech.2023.100227