July 2015: Q+A with University of Maryland Researcher Dr. John Lea-Cox

Photo courtesy of Edwin Remsberg/University of Maryland, College Park

Meet Dr. John Lea-Cox, Professor and Nursery Extension Specialist in the Department of Plant Science and Landscape Architecture with the University of Maryland, College Park. Dr. Lea-Cox is a nutrient and water management expert and currently leads a team of researchers focused on developing and implementing wireless water and soil sensor technology. To watch a video about the wireless networks, please click here. To learn more about the how this technology improves strawberry production, please click here.

Q: How does the wireless technology work?

We use sensors to measure changes in soil moisture and other environmental data (for example rainfall, light, air temperature, relative humidity and wind).  These sensors are connected to radio “nodes” in the field that log this data (typically every five minutes) and transmit that data either to a base-station computer on the farm, or alternatively via cellular networks to a “cloud” server.  Once this information is captured, we use computer software to provide intuitive graphs, alerts, irrigation scheduling and other tools for each farm site via the internet –directly to anyone who has access to the farm website.  Each farm’s website is password protected, so that data remains private.  In this way, farmers and managers can access this information to make better decisions about when and if they need to irrigate.

Q: Why is this information important for nutrient management and water conservation?

Sensors add tremendous value to making good decisions because growers can rapidly assess and quantify these conditions from various strategically placed sensors.  Using the new sensor control technology we developed,  sensors turn on the water only when soil moisture or environmental conditions indicate that plants need water.  Most often it is not about when to turn the water on – it’s about when to turn it off.   Sometimes, we totally miscalculate how much water it takes to replenish water in the root zone – and that is how we lose most of our water.

By knowing when to turn the water off, we achieve our greatest water savings. These savings are typically between 40 and 70 percent of prior water use — depending on the crop, the time of year and how good the irrigation manager is against whom we are comparing our data.   And if we reduce the amount of irrigation water applied, we have shown that we can reduce the leaching of soluble nutrients from the root zone by up to 50 percent.

Q: Why did you decide to use this technology for strawberries?

Our first research project was targeted at high-intensity ornamental production systems – container-nursery and greenhouse systems since they almost always require irrigation and using water and nutrients wisely is a top concern for this industry, nationally.   However, strawberry production faces similar challenges since they are grown very intensively, often on sandy porous soils.  So, by employing exactly the same tools, we hope to demonstrate similar savings for a very economically important food crop.  The National Strawberry Sustainability Initiative grant we received from the Walmart Foundation provided us with the opportunity to work on this with two very progressive fruit and vegetable farmers in Maryland, investigating this technology with strawberry production.

Q: Do any strawberry growers currently use this technology?

Many strawberry growers use some form of controlled irrigation method, perhaps combined with irrigation sensing devices.  But, getting and interpreting the data from these types of sensors is most often very tedious and time-consuming for the grower. To our knowledge, this affordable real-time wireless technology, which delivers the results directly to a farmer’s cellphone, has not been used very extensively in strawberry production until now.

Q: How have these growers benefited from this technology thus far?

Of course, the year we implemented the irrigation control in this study had to be one of the wettest years in the past decade in Maryland.  So, we haven’t seen many differences between irrigation treatments in terms of growth or yield this year, but we are continuing the study for another year in 2015/16.

However, one of the additional benefits we have explored with this project is the use of frost-detection sensors placed in the strawberry canopy at ground level.  Frost protection is a very tedious activity for growers in spring, as they have to get out of bed at 4am if they anticipate that frost may occur that morning.  They have to then start overhead irrigating the crops as soon as those temperatures approach freezing.  Since these frost-detection sensors measure leaf and flower temperature in the canopy, our growers literally have “eyes” in the field.  They can see this data updated every five minutes and also monitor wind and air temperatures right on their cell phone or office computer.  Both growers really liked the utility of this application, and particularly the alert feature which texts their phone to alert them of perilous conditions.  The technology doesn’t substitute for what the farmer has to do to turn on the pumps and sprinklers, but it does allow for some greater peace of mind.   We are also documenting the economics of the time, resources and labor savings we are able to achieve with these systems. 

Q: Why is technology important for the future of agricultural research and science?    

I truly believe that we are just beginning to explore how technology can better inform us and automate some of the tedious activities we have to do in farming. Ask most farmers about their greatest management issues, and usually the answer is (1) labor and (2) having enough time to get everything done every day.  We have transitioned from a largely agro-industrial society to a knowledge-based economy in the past 50 years.  However automating food production – especially for perishable crops – has yet to really occur, except for the most valuable crops.   So, we are going either have to be willing to pay a lot more for those crops that require high-labor inputs for producing, picking or processing, or we will have to find new and efficient ways to address these challenges with technology.

Q: Do you have a favorite way to eat strawberries or a favorite strawberry recipe?

My favorite? Chocolate-covered — nothing else required!

Q: What’s the best way to grow strawberries at home?

I’ve always thought that the most fun way to grow strawberries is using a vertical strawberry planter on your back deck or patio. Check them out on the web – there’s lots of different planters out there which you can plant with different strawberry varieties.

Photo courtesy of Edwin Remsberg/University of Maryland, College Park

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Agriculture is America. In short, the agriculture industry – sustained in large part by the American land-grant university system through Colleges of Agriculture, Agricultural Experiment Stations, and Cooperative Extension – is integral to jobs, national security, and health.


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