Irrigated Agriculture
MEA provides an extensive range of high quality and cost effective measurement systems for use in Irrigated Agriculture.
MEA's soil moisture monitoring products include a comprehensive range of soil moisture tension and content sensors. The sensors can be connected to manual readers, to low cost data loggers or to our telemetry systems. There are options available for all needs and budgets.
Our Automatic Weather Stations have an unmatched reputation for data integrity and reliability.
MEA's products are available through a network of accredited Resellers. (If you are interested in becoming an MEA reseller, contact MEA).
MEA's History In Agricultural Monitoring
MEA has been building measurement systems for the Agriculture industry since 1990.
MEA's products are well proven. Many began life as new tools or technology for the research community. For a researcher, the ultimate reward is having ideas accepted by growers. And this is the role MEA has taken - converting research systems into practical every day tools. Soil moisture monitoring for developments such as RDI (regulated deficit irrigation) and PRD (partial rootzone drying) are prime examples of this. MEA measurement systems continue to underpin agricultural research and development.
Why Make Measurements?
With increased demands on the performance of agricultural crops every year there are a number of key areas where monitoring has immediate and long term benefits.
Increased Quality
The pressure on growers to produce higher quality grapes in the wine industry is increasing. Research has proven that deficit irrigation practices used in conjunction with soil moisture and climate information can increase crop quality and value.
Increased Water Use Efficiency
Water is fast becoming the most valued resource in Australia and its availability is the key issue relating to the success of irrigated crops. Extensive research is being performed to determine how to make best use of available water by improving irrigation timing and reducing the plant's water requirements using strategies which manipulate vegetative growth or transpiration rates. These practices can only be effectively implemented and maintained through the use of monitoring technologies.
Long Term Data
The long term benefits of recording climate and soil moisture data include the ability to compare crop data (yield, quality, disease) against measured data to promote a greater understanding of how the crop functions. Temperature and sunlight remain the key factors that effect plant growth and the ability to assess this in a quantitative manner becomes a great asset to the property manager.
What To Look For When Choosing A Measurement System
The most important factor to consider when choosing a measurement system is the measurement itself. While this is an obvious statement, it is easy to become distracted by the features other than the quality, reliability and meaningfulness of the measurement. The most beautiful software presentation of data from an inaccurate sensor is still just inaccurate data. A sensor which is accurate, reliable and has a long term calibration will provide useful information.
An appreciation of the basic factors which govern how well a system performs is essential to making an informed choice.
Accuracy
This is perhaps the key factor to use when assessing a measurement system. Accuracy is the range of error within which a sensor can be guaranteed. For example a temperature sensor may have an accuracy of +/- 0.5 degC. This says that at any time this sensor will read a value that is not more than 0.5degC from the real value of temperature.
Some sensors also state different accuracies for different parts of their measurement range. A humidity sensor may be +/- 3% over 10 to 80% but +/-5% over the range 80 to 100%. If it is important to make accurate measurements of humidity in the range 80 to 100% for fungal disease monitoring for example then it is important to choose a sensor that can offer the best accuracy in this range.
Accuracy is easily understood by considering an archer shooting arrows at a target. If the archer is accurate, all arrows will end up close to the centre of the target. If all the arrows are clustered on one side of the target, the archer is not accurate but is consistent (repeatable). If the arrows are scattered all over the target, they are neither accurate nor repeatable. The best sensors are both accurate and repeatable.
Note also that there is a price premium attached to higher accuracy sensors and ultimately the decision will be based on a sensor with acceptable accuracy at an affordable price.
Calibration and Drift
All sensors have some calibration which translates the electrical measurement into a real world value. Some sensors have fixed calibrations, however many are factory calibrated and require regular recalibration (annually or bi-annually) to correct for the effects of drift. Drift can be accelerated by poisoning from agricultural sprays or other airborne chemicals.
This again relates to the quality of the sensor and how capable it is of maintaining a good calibration over an extended period of time.