Can RFID Track Tree Growth?

A nurseryman here in Australia recently approached me and asked if there was an RFID tag that could monitor the growth of a tree over a number of years. His concept is to look at various inputs and compare which produced the best results. Have you heard of a tag that can do this?

—Sean (Sydney, Australia)

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Sean,

I am unsure of what this person wants to do. RFID can be used to identify trees uniquely, so the nurseryman could track each trees growth, but the tag would not report that a tree grew, for example, 5 inches since the tag was last read.

In 2010, we published an article about Hawaiian Legacy Hardwoods planting an RFID tag alongside saplings to enable the grower to track each sapling's lineage, by storing data not just about that tree (linked to a tag's unique ID number), but also the mother tree (the source of the tree's specific seed). This is helping the company to better manage forest diversity, and thus ensure a healthier tree crop (see RFID Helps Foresters Grow Koa Trees).

Back in 2004, we wrote about graduate students at the University of Washington, in Seattle, embedding RFID transponders in trees. The university's Precision Forestry Cooperative was set up with funding from the state legislature to use advanced technology to improve conservation techniques in the forestry industry. After two years of preparation, students embedded the tags in two-year-old saplings to determine if RFID could be used to identify trees that had been genetically modified to grow more rapidly. The trees are planted and monitored. Eventually their seeds are harvested to create a new generation of faster-growing trees. Big money was invested in the genetic modification, so the seeds of the original saplings are very valuable.

Students embedded a 134.2 kHz glass-encapsulated transponder from Texas Instruments in each sapling. Each tag has 80 bits of read-write memory, which can be used to store a serial number and other data about the sapling. A scientist with a handheld computer equipped with a reader can go to an area of the forest where genetically modified saplings have been planted, scan the tag and gather data about the tree in the field. Since trees grow from the top, the transponders stay at the same height. New growth forms around the transponder, so it becomes completely embedded in the middle of the tree trunk (see Out on a Limb and RFID in the Forest).

With the above examples in mind, the nurseryman could use a handheld interrogator to read a tag, call up that unique plant's file and input information, such as its current high and general health. This could later be transferred to a laptop via a Bluetooth connection or a cradle. I hope that helps.

—Mark Roberti, Founder and Editor, RFID Journal