Agricultural Sensors for optimal water and nutrient use efficiency
By Dr. Louis Ehlers Manager
Nutriology® Solution Development
Agriculture consumes around 70% of global freshwater resources and increasing water scarcity fuels the demand for new innovative agricultural solutions.
Innovations in information communication technology accelerated the convergence and integration of IT with precision agricultural technologies such as automated irrigation, remote operation and real-time sensing. These emerging trends aims at increasing efficiencies, productivity and profitability, while minimizing unintended impacts on the environment.
It is believed that 21st century robotics and sensing technologies can make crop production significantly more efficient and more sustainable. These technologies include fruit and flower detection and recognition; robots for pruning, thinning, harvesting, mowing, spraying and weed removal; aerial and ground sensors for soil, water and crop monitoring, prediction and decision making. Although some of these technologies are already available, most are still at the research stage.
Figure 1: An installed dendrometer monitors the circumference of a fruit tree
A large variety of water, soil and crop sensors are available to help farmers monitor and optimize crops. A sensor is an electronic device that recognizes and responds to a specific input (light, heat, moisture, pressure, etc.) from the physical environment.
These include electrochemical sensors (pH and soil nutrient levels), optical sensors (different frequencies of light reflectance in near-infrared, mid-infrared, and polarized light spectrums), radiometric sensors (CEC and soil texture), acoustic sensors (wind and rain), mechanical sensors (load cells, strain gauges and tensiometers), dielectric soil moisture sensors and agricultural weather stations.
Sensor output is generally a signal that is converted to a readable display on the sensor itself, or is transmitted electronically over a network for display or further processing.
Figure 2: A Pessl agricultural weather station Figure 3: A fruit size sensor
A wireless sensor network (WSN) refers to technology that enables communication and access to the internet without cable connection between electronic devices and computers. These networks usually consist of a number of low-cost, battery-powered nodes equipped with multipurpose sensors (spatially distributed) which collect appropriate information and transmit it wirelessly to a central base-station (or a Cloud). The base-station (or Cloud) uses the data dynamically for monitoring and control purposes, or stores it for future processing. The fundamental properties to the proper operation of a WSN depends on its specific application and are mainly as follows:
- Reliable network connectivity;
- Sufficient accuracy of measurements;
- Low power consumption or renewable sources like solar options; and
- Data security.
Benefits of sensor technology in agriculture
As an integral part of precision agriculture, agricultural sensor technology is a cost-effective and time-saving solution to monitor a variety of parameters crucial for optimum crop and plant growth. The main benefits of using wireless sensor technologies in agricultural applications are as follows:
- Real-time data unlock the potential for analysis and information-driven solutions which can send alerts to ensure process optimization.
- Wireless monitoring solutions offer the ability to use software for data viewing, analysis and comparison from any device.
- The installation process is easy, quick and cost-effective with sensors that can function up to 10 years without battery replacement.
- Monitoring critical parameters is crucially important to ensure optimum productivity with low operational costs.
Advances in crop sensing technology created a foundation for obtaining real-time information. Instead of making decisions based on some hypothetical average condition, it provides a solid base to farmers to adjust production strategies at any time to ensure optimal nutrient and water use efficiency.