Comfortable Crops – AG INFORMATION NETWORK OF THE WEST
The OSU plant researcher Dr. Chad Higgins conducted an experiment with dry grasses in which one section was shaded by solar panels and the other was not. For grasses in shady areas … Oregon State University scientists have found a resource to increase agricultural production on dry, unwatered farmland – solar panels.
In a study published Thursday in the journal PLOS One, a research team from the OSU College of Agricultural Sciences found that grasses preferred by sheep and cattle thrive in the shade of a solar array installed in a pasture on the OSU campus .
The results of the OSU study suggest that locating solar panels in pastures or agricultural fields could increase crop yields, said author Chad Higgins, associate professor in the Department of Biological and Ecological Engineering.
“There are some plants that are happier in shady environments,” he said. “The amount of water that went into the production of these plants is enormously less than in the open field. You get twice the yield, less water and all of the solar energy. “
The concept of jointly developing the same area for both solar photovoltaics and conventional agriculture, known as agrivoltaics, dates back to the early 1980s. Ground mounted solar systems are not typically placed on farms to grow crops.
“The idea of putting solar panels on the farm is not new,” said Higgins. “The difference is that this solar system was installed without wanting to affect crop production. It was a coincidence. Nobody developed this system. Now we are trying to develop a deeper understanding of how we can design the system in such a way that it is technically feasible, environmentally friendly and economical. “
OSU has 10 acres of solar project sites in Corvallis that have a capacity of 2.6 million kilowatt hours of electricity per year. This study focused on the 35th Street Solar Array installed on the west side of the OSU campus in 2013.
One day, Higgins and colleagues were walking past the row and noticed that green grass was growing in the shade of the panels. In May 2015 they installed microclimate research stations that recorded the mean air temperature, relative humidity, wind speed, wind direction and soil moisture. By August, the instrumentation showed that the areas under the solar panels had higher soil moisture for the entire three month period.
The result is impressive, said Higgins. The areas under the array produced twice as much plant material as the unshaded areas, including an increase in the nutritional value of the plants. The researchers also noted a significant increase in plant growth in the late season.
“It’s like a turtle and a rabbit race,” said Higgins. “The plants that experience full solar radiation use their water resources as quickly as possible. They grow as far as they can and then die. On the other hand, the plants in the shade take a sip of water because they are less stressed and keep chugging. “
The next step is to test the effect of placing solar panels on certain high quality plants that are suitable for shady conditions, Higgins said.
The study is part of a larger effort to understand the relationships between energy, water, and food systems, said Higgins, founder of the Nexus of Energy, Water and Agriculture Laboratory at OSU. The research team consisted of Elnaz Hassanpour Adeh, a PhD student in the OSU’s water resource engineering program; and John Selker, Distinguished Professor, both in the Department of Biological and Ecological Engineering.