New ag-tech innovations show promise

Boston, Mass.-based Massachusetts Institute of Technology (MIT) researchers said this week they’ve engineered a way to use the natural power generated by trees to recharge battery operated sensors that can detect forest fires.

The development figures prominently in an emerging field of technology in which wireless sensors, monitoring devices and novel uses of biological systems for agriculture are being put to use to save resources and improve growth in plants.

There is activity in this emerging market, David Aslin, managing director of AslinVC told the
Cleantech Group (see USDA hands out $35M for cleantech projects).

“But for the most part, precision agriculture has not moved along in any
visible way,” Aslin said.

In the case of the MIT research team, the new system produces enough electricity to allow the temperature and humidity sensors to wirelessly transmit signals four times a day.

It also can send an alert if the device detects a forest fire, according to researchers. Each signal hops from one sensor to the next until it reaches an existing weather station. From that location, the signal is beamed by satellite to a forestry command center in Boise, Idaho.

The bioenergy harvester battery charger and network is being developed by university researchers, Andreas Mershin and Shuguang Zhang. The two researchers have launched a spin-off company Voltree Power based on the technology.

The team said it expects to begin pilot tests this spring on a 10-acre plot of land provided by the U.S. Forest Service. The researchers said it expects that it will need one instrument for every four trees on an acre of land.

Scientists have long known that trees can produce extremely small amounts of electricity. But no one knew exactly how the energy was produced or how to take advantage of the power.

In order to solve the puzzle of where electrical voltage comes from, the researchers set up a number of experiments, which revealed that electricity was not being generated due to a simple electrochemical redox reaction (commonly known as the power generated by potato batteries). It turned out the basic electrical current is driven by an imbalance in pH between the tree and the soil it grows in, the researchers said.

The MIT researchers are not alone in their innovative efforts. Several other new startups and university projects are underway in the area of precision agriculture.

In simple terms, precision agriculture is devoted to applying technology to better manage use of water and other natural resources to improve agricultural production. To date, the private sector has made a significant investment to tailor information technologies for agricultural applications, according to experts.

The other potential sensor applications for agriculture and vineyards include optimizing the use and timing of fertilizer application as well as early warning for frost and excessive heat and prediction of the potential for disease and pest outbreaks.

Some of the other wireless-sensor startups in the area of precision agricultural include Grape Networks and Fruition Sciences. Both are focused on the high end of the winery market.

Fruition Sciences is a startup that was spun out of University of California at Berkeley. Aslin said he’s an investor in the university spinoff. The company is currently conducting pilot tests with its networked water sensors in Northern California vineyards.

The principle idea around the startup is to better monitor rates of evaporation out of wine leaves and thereby adjust water irrigation needs. Common practice is to flood vineyards with more water than is required. This can harm the overall quality of the grapes, and also lead to a great deal of wasted water.

“The economic value of much less water usage and being less wasteful has benefits for the environment,” Aslin said.

Also this week, Ohio State University agriculture engineers said they’d developed a grain-drying technique to help farmers control energy costs by as much as two-thirds, compared to common methods.

The researchers said natural-air grain drying system involves transferring wet corn (20 percent to 24 percent moisture) directly to bin storage (see Vertical farms for food and restoration). That bin includes a perforated floor, which permits natural-air drying fans to dry the grain to an optimum 14 percent to 16 percent moisture over the period of a month.

According to a study conducted by Hansen and other researchers, 80 percent of Ohio's corn growers dry at least part of their corn directly on their farm. Less than 10 percent of farmers use natural-air grain drying.

Researcher Robert Hansen said other benefits besides the lower-energy requirement (common drying is done at 200-220 degrees F) is the fact that air grain drying typically results in higher grain quality. Hansen said he recently demonstrated the technique at the Ohio State University's Farm Science Review to help educate farmers on the equipment and the costs of setting up a natural-air grain drying system.