Advancements In Grape Field Monitoring Systems
April 1, 2008 One of the most talked-about ag technology products in recent years has been the development of the remote field monitoring system. The idea of this system is to deliver climate and other data from your vineyards directly to your personal computer. There are more than 10 manufacturers of various types of remote field monitoring systems, with many having entered the market in the last five to 10 years.
Field monitoring systems can be equipped with sensors to record climate data (temperatures, relative humidity, rainfall, wind speed, and solar radiation) from which you can calculate evapotranspiration, growing degree-days, or create notification points (i.e. a frost warning system). In addition, these systems can be equipped with sensors to record soil moisture levels and plant growth rates, which can form the basis of deciding when to irrigate. The system can also record how long the irrigation system was run. In addition, in-canopy temperatures and leaf wetness levels can be used to help determine the treatment timing for powdery and downy mildew.
A Brief History
Monitoring what is going on in a vineyard began more than 40 years ago when we installed tensiometers or gypsum blocks to measure soil moisture levels. On a weekly basis during the growing season, we walked into the vineyard, wrote down the current reading, then returned to the office or pickup to add the new data to our graph and decide when we needed to irrigate.
Ten to 15 years ago, the “data logger” was introduced for general commercial use. This allowed field data to be recorded more frequently (i.e. once a day, once an hour, or even once every minute). Now, the person walking into the vineyard each week could download a week’s worth of information.
In recent years, remote downloading of field loggers has been done using cell phones or a combination of radio telemetry and cell phones. Loggers are regularly downloaded (every 15 minutes or more frequently) to a Web site, which we in turn can access from our computer.
During the last 40 years, two things have occurred. First, there has been a huge increase in the number of climate, soil, and plant sensor instruments. Forty years ago, we had tensiometers and gypsum blocks; today we have more than 60 different types of soil moisture measuring instruments. Second, we have automated the collection and transfer of data.
Remote Systems
There are two types of remote field monitoring system configurations —the “single unit logger” and the “distributed node.” The most popular system approach consists of a single unit logger to which you can attach a series of instruments (sensors). All of the instruments must be hard-wired to the single unit logger (some manufacturers do allow instruments to be remotely located at up to 1,000 feet away). The logger unit is equipped with a cell phone which transfers data to a Web site. The Web site is then accessed by the user to view the data.
In the distributed node approach, a “base” station unit is used in combination with “nodes,” which are loggers that collect data then send it by radio telemetry to the base component. Using this approach, one can collect data at a base station from points distributed from ½ to 1½ miles away. Data from the “base” component can be downloaded manually (i.e. once a week), or a cell phone can be used to transfer data to a Web site to your PC the same as is done with the single unit logger setup.
Most of the field monitoring system providers do a fairly good job on their Web sites by providing graphic displays of sensor data. Almost all have an Excel download capability for individuals to do their own analysis. However, some manufacturers are quite “flashy” in their graphics and get carried away with projections for vineyard activities (i.e. projecting irrigation needs). A grower should understand what is going on in a Web site calculation before using the results.
Reliability And Cost Of Sensors
If you are basing decisions on field data from a field monitoring system, reliability and accuracy are important, as well as the life expectancy of the sensors. The most reputable suppliers of these systems manufacture their own instrument sensors. Other suppliers use off-the-shelf suppliers whose sensors have a life expectancy which is typically five years or less. In the end, there is the typical tradeoff of quality for cost, though there are some higher cost manufactures with lesser quality.
There are two components of costs. One is the initial capital investment and the second is the annual cost to download data (i.e. cell phone to Web site). Capital costs depend on the manufacturer and the number of sensors added to the system. For a single unit logger system, capital cost typically ranges from $3,000 to $5,000 per unit. For the distributed node systems, the base station cost is $300 to $800 with each node at $800 to $1,200 (depending on sensors).
In addition to the capital costs, there are also annual fees for the transfer of the data to a Web site. These range from $300 to $850 per unit (i.e. per single unit logger or per distributed node).
As we look at the use of current technology in our vineyard operations, we need to remember that all of the approaches described above are viable and effectively used today. The questions are, how much data do you want, and how fast do you want to receive it? If you are considering using some of the newer technologies, be sure to talk to current users or a consultant who has some knowledge and experience with these technologies. And remember that existing technologies may just as well meet your needs.
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