Written by Debby Wechsler
Ben Butler – Butler’s Orchard
Project: Implementing Low-Cost Wireless Sensor Networks for Irrigation, Nutrient Management and Frost Protection of Strawberry
John Lea-Cox, University of Maryland
When George and Shirley Butler started Butler’s Orchard in the early 1950s as a pick-your-own farm, few people were aware of the concept. Their children and grandchildren now run the much-expanded farm, including Ben Butler, assistant farm manager and third-generation Butler farmer. Located within suburban and highly developed Montgomery County, Maryland, where few farms remain, the Butlers provide a special on-farm experience for their huge customer base, including many school groups for blossom tours in the spring and pumpkin tours in the fall.
Their progression of pick-your-own crops starts with strawberries and peas in the spring, continues through tart cherries, blueberries, black raspberries, blackberries, potatoes, tomatoes, herbs, flowers, fall red raspberries, pumpkins, and apples, and ends with Christmas trees. They also have a retail farm market and bakery, with about 5 acres devoted to producing vegetables for the retail market.
Strawberries have been grown on the farm since 1953 and the Butlers currently have 18 acres in matted row production. Says Ben Butler, “We explored plasticulture about 15 years ago, but it just didn’t fit into the way we do things. It requires more intensive management, especially for row covers and frost protection, with the plants blooming several weeks earlier, and is more difficult to fit into our rotations.” The Butlers typically keep a strawberry planting for 4-6 years and do not fumigate.
Ben says he helped plant the seed of the idea for the Maryland Strawberry Sustainability Initiative project exploring the use of wireless sensor technology in strawberries. “I took a class on greenhouse technology with Dr. Lea-Cox when I was in college at the University of Maryland, and started to wonder ‘How can I use this in our operation?’ I felt that frost protection was a major challenge, and I knew my father would be out checking thermometers in the field one at a time – and then I’d get a call in the middle of the night to help start the irrigation. I asked Dr. Lea-Cox if there was anything growers could do to better manage this, and I think he kept it in his head, and later came to me with the idea for a proposal.”
The project set up an array of air temperature and soil-moisture sensor nodes in a 1.5 acre field, and also set up sensors in a low-lying area likely to frost before the rest of the farm. Besides monitoring temperatures, the sensors could collect data relating to soil moisture and fertilizer levels, with a goal of making it possible for growers to provide optimum growing conditions to the crop and reduce excessive water and fertilizer application. The project also provided a weather station that collects even more data, including air temperature, relative humidity, solar radiation, wind speed and rainfall. Ben can access all of this information both from a base computer and through the internet on his iPhone.
The frost alert function wasn’t needed this spring because of a lack of frost events, but Ben has already found many other ways to use the system. “It generates a ton of data. One of the nicest parts is that it can measure bloom and air temperatures, which is really helpful for evaporative cooling during harvest. I’m actively using the program and will still use it for other crops when strawberries are finished. I’d love to use it in blueberries to monitor soil moisture. The weather station is almost invaluable at this point – right now I’m watching wind speed and direction as I get ready to spray the sweet cherries.” He’s also excited about another potential project that would incorporate sensors for leaf wetness into a forecasting program for grey mold (Botrytis) and anthracnose in strawberries, indicating when conditions are conducive to outbreaks.
“We really believe in the project and the methods,” says Ben. “Sustainability has become such a polarized buzz-word. I think a lot of farmers back away because of misconceptions.”