A “Nest” for Your Lawn

Duke Smart Home experiment makes efficient work of lawn care

What if there were a service like Nest for your lawn?

That’s the goal of a new “Smart Lawn” experiment at Duke University’s Smart Home, headed by Amilcare Porporato, the Addy Professor of Civil and Environmental Engineering, and his postdoctoral researcher, Jun Yin. A network of sensors in the ground gather data, complemented by a tower taking atmospheric measurements. The setup’s shared hardware monitors water, carbon, and energy fluxes through evapotranspiration, rainfall, sun radiation, and carbon uptake by the vegetation.

Launched in November 2015, the project is a collaboration with Jim Gaston, associate dean for undergraduate research, Lydia Olander, director of the Ecosystem Services Group of the Nicholas Institute, and Mark Schmidt, principal scientist at John Deere.  The system is designed, on a small scale, to determine what Duke’s live-in student laboratory needs for its lawn. It will inform the optimal management of the Smart Home’s water cistern, irrigation systems, types of crops and lawns, and fertilization schedule. The goal is to optimize the retention of nutrients and the use of water and other materials and maximize the related ecosystem services.

On a large scale, the findings will help calibrate and set parameters for computer models to predict the precise needs of lawns and farmland in North Carolina and in general for the Southeast US where irrigation water needs are particularly variable thought the growing seasons. And if these predictions can be made on a small enough set of variables that can be easily monitored, a system like Nest for your lawn would not be far away.

“One of our goals is to see how much water is needed for the lawn and how much rain harvested by the cisterns can be used for the Smart Home’s laundry and toilets,” said Porporato. “Since the climate changes unpredictably we need long-term measurements and models that account for this uncertainty. This is a necessary step to use sustainably soil and water resources and reduce the impact of our buildings on the environment. It is exciting to work at the Duke Smart Home for this research as it is also a great opportunity to interact with students interested in these specific problems of water resources, environmental engineering and sustainability.”

And if you’re wondering how the Smart Home’s lawn is doing at this very instant, you can check out real-time measurements of carbon dioxide, soil moisture, rain, wind speed, net radiation, net radiation corrected by wind speed, temperature/humidity at three levels, soil heat flux and soil temperature.