NATICK, Mass. (Oct. 16, 2015) -- Don Holman was raised on a farm in Michigan and served 30 years in the Navy, which makes him a perfect fit to help test whether American warships could one day grow their own fresh vegetables.
Inside a repurposed former refrigerated shipping container tucked behind the Combat Feeding Directorate, or CFD, at Natick Soldier Research, Development and Engineering Center, Holman has been growing lettuce since August in a climate-controlled, 40-by-8-foot "hydroponic farm." What will be a year-long effort has been undertaken for the Navy, which aims to explore the capability of growing produce at sea utilizing hydroponics technology.
"I want to see what can grow and what can't grow," said Holman, an engineering technician with the Joint Foodservice and Engineering Team at CFD and a retired command master chief. "We want to experiment with all varieties of vegetables and see how much produce we can produce.
"The end goal is to provide the Navy a technical report detailing the test results of the equipment, its possibilities and limitations."
Currently, ships on long deployments receive fresh fruit and vegetables by helicopter or by tensioned cable between ships with a pulley system.
"Much of it comes from locally-procured overseas sources," Holman said.
The hydroponic farm is growing produce from seeds without using soil. Seeds germinate and grow first in peat moss plugs placed in trays and then are transferred into vertical "towers." Through each step, the seedlings and, later, plants are moistened with nutrient-enriched water that is pH balanced.
"You can grow more plants in a vertical arrangement, rather than a horizontal configuration," Holman said. "It takes up very little floor space when it's hung vertically. There is more growth in less area."
The space is illuminated with light-emitting diode lights, and the 24-hour operation simulates daytime and nighttime conditions and accelerates plant growth. The container has Wi-Fi and Bluetooth capability and is equipped with an infrared camera.
"All functions are instrumented and automatically controlled, which simplifies data collection," Holman said. "The Wi-Fi allows one to monitor the farm from an iPhone at home, to ensure the farm's operating correctly."
The current hydroponic farm runs efficiently, consuming approximately 6.8 kilowatt-hours of electricity during daytime operations and 1.2 kWh at night.
"The power requirements are minimal," Holman said. "We're still collecting power consumption data, as well."
Only 10 of the 280 gallons of water circulating through the farm's vertical towers are consumed daily.
"You can't do that on a dirt farm," Holman said. "It's going to take a lot more water than that. The manufacturers estimate a 90-percent reduction in water consumption."
As Holman pointed out, there are other advantages over outdoor farming.
"There are no insects," Holman said. "We do not have the diseases normally associated with a dirt farm. The atmosphere is controlled for temperature and humidity as well as the nutrients and pH levels of the water - an obvious advantage over a dirt farm."
The first lettuce crop was harvested Oct. 14. After it's thoroughly tested by a CFD microbiologist, the produce may be used in the Natick Soldier Systems Center dining facility.
"We continued for several weeks planting lettuce to learn the farm and to make necessary modifications," Holman said.
Broccoli, Brussels sprouts and bush beans - currently growing in trays - will move to the towers next.
"Now that we've learned how to operate the farm, we're going into full test mode, to determine the farm's production output," Holman said.
According to the manufacturer, the farm will produce the equivalent of an acre of land.
"It remains to be seen," Holman said. "That's why we're testing."
Does Holman believe that hydroponic farming technology will translate well to today's warships?
"Space is always a premium aboard ship," Holman said, "but once that issue is resolved, I don't think the challenges are going to be that great."
Holman went even further than that.
"If the farm tests well, its potential wouldn't be limited to just the Navy," Holman said. "The Army and Marine Corps would benefit greatly from reduced produce costs, shipping costs, and the logistics of moving produce on the battlefield. I think the applications for all the services are great."