Vegetable growers, wine grape and other fruit growers, flower and ornamental growers and food processors all benefit from water sensors for accurate, steady and numerous moisture readings. But current sensors are large, may cost thousands of dollars and often must be read manually.

When inserted into a plant stem or into soil, Cornell’s sensor is fitted with wires that can be hooked up to a card for wireless data transmission or is compatible with existing data-loggers. They can be left in place for years, though the units may break in freezing temperatures. Such inexpensive and accurate sensors can be strategically spaced in plants and soil for accurate measurements in agricultural fields.

For example, viticulturists use precise irrigation to put regulated water stress on grapevines to create just the right grape composition for a premium cabernet or a chardonnay wine.

“One of our goals is to try and develop something that is not only a great improvement, but also much cheaper for growers and others to use,” said Alan Lakso, Professor of Horticulture, who has been working on water sensing for twenty years.

The sensors make use of microfluidic technology, developed by Abraham Stroock, Associate Professor of Chemical and Biomolecular Engineering,that places a tiny cavity inside the chip. The cavity is filled with water, and then the chip may be inserted in a plant stem or in the soil where it, through a nanoporous membrane, exchanges moisture with its environment and maintains an equilibrium pressure that the chip measures.

Using chips embedded in plants or spaced across soil and linked wirelessly to computers, growers may “control the precise moisture of blocks of land, based on target goals,” said Vinay Pagay, who helped develop the chip as a doctoral student in Lakso’s lab.

The researchers seek to understand how values gathered from sensors inside a plant and in soils relate to plant growth and function, so that growers can translate sensor values and optimize management.

Ernest and Julio Gallo Winery and Welch’s juice company have already expressed interest in the sensors.

The Cornell Center for Technology Enterprise and Commercialization is handling the intellectual property rights. The researchers hope to commercially produce the sensors for as little as $5 each.

Photo: Vinay Pagay holds a "lab on a chip" that measures moisture levels in soil and can be embedded in plant stems for accurate information on water stress.