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Floating cows and manure robots: A dairy farm on the sea

Aboard the Dutch vessel that’s redefining agriculture

By Tracy Staedter

Cheese may seem an unlikely factor in maritime greatness. But in the late 1500s, fleets from The Netherlands took to the seas to explore India, Africa, and Indonesia, stockpiled with leidse kaas, which means “cheese from Leiden,” in South Holland.

The cheese was made from the milk of the blaarkop cow, also known as the blister head, a medium-sized breed with a square white face and black or red patches around its eyes. Farmers churned the blister head’s rich, fatty milk into butter and used the remaining skim milk to make leidse kaas. The cheese, which had a longer shelf life than higher-fat varieties, gave Dutch sailors a nutritional advantage over nations like England, which didn’t become a major sea power until the 1600s.

More than 400 years later, The Netherlands is a top dairy producer in Europe, Rotterdam is the continent’s busiest port, and a buoyant dairy farm moored in the city’s Merwehaven Harbor, amid cargo ships, cranes, and containers, has paired dairy and shipping in a new way.

Floating Farm, the vision of engineer and entrepreneur Peter van Wingerden and his wife and business partner, Minke van Wingerden, is a 4,800 square-foot vessel that’s home to 35 dairy cows. It opened in May 2019 as an all-in-one floating cow farm that also houses the machinery to make milk and yogurt and a store for consumers.

From shore, passersby hear the lowing of cows and see two of the farm’s three levels. A roofed, open-air stable on the top floor houses the 35 Meuse-Rhine-Issels, docile and disease-resistant cattle bred in a part of The Netherlands where the Meuse, Rhine, and Issel rivers intersect. White, with large reddish splotches, the cows produce 185 gallons of high-quality milk per day in total — ideal for yogurt and cheese. The animals, attended by one farmer, lounge, munch hay, and are milked in the stable, which affords a nice view of the 50 solar panels on a raft that deliver nearly half of the farm’s electricity. A sturdy, railed gangplank gives the cows access to a small meadow onshore, where they can graze and stretch their legs.

A gangplank for humans leads down to the middle floor, situated at sea level. Enclosed by translucent, plastic walls, the room contains a small factory, where three employees make and package the Melk-branded milk and yogurt and sell them at a retail counter. The bottom floor, below sea level, accommodates storage and electrical and plumbing systems.

Van Wingerden says he designed the farm to better connect food production to urban living. Because it’s located in the city, the farm helps reduce the carbon footprint of food delivery, and because it floats, it can adapt to rising ocean levels caused by climate change, he says. Its high-tech, modular, and sustainable design could also attract young people to agricultural jobs. Van Wingerdens says he chose cattle instead of vegetables because managing large animals inside the city would require more creative thinking and generate more buzz. “If we would have put a greenhouse on a floating device,” he says, “nobody would have come.”

“The most important thing in life is food. So, let’s show to people that it’s more interesting to become a farmer than a banker.”

Peter van Wingerden, co-creator of Floating Farm in Rotterdam

Putting a cow farm on the water seems like a natural move in a country where half of the population and a third of the land lies below sea level. “Netherlands” means low-lying land; to push back the North Sea, the Dutch have, over the centuries, built a 13,670-mile network of dikes, pumps, and polders (land reclaimed from a lake, river, or sea). But the country is sinking between 1.5 and 3 inches per year and sea levels are expected to rise about 10 to 40 inches by 2100. Tens of thousands of Dutch already live on floating houses, and in recent years, the trend has moved to commercial buildings and even entire neighborhoods. Farms could be next.

Van Wingerden says he’s gotten requests to build floating dairy farms in Singapore and China and inquiries from private companies in New York City — but the COVID-19 pandemic interrupted those conversations. Undeterred, he’s planning a second farm in Rotterdam harbor — this one designed for egg-laying hens. “The most important thing in life is food,” he says. “So, let’s show to people that it’s more interesting to become a farmer than a banker.”

Changing tides

The idea for Floating Farm arose from a hurricane. On October 29, 2012, Hurricane Sandy struck New York City, causing an estimated $19 billion in damages. Months later, van Wingerden and several other Dutch architects and engineers visited New York to propose ways the city could become more resilient to storm surges.

Many of van Wingerden’s peers focused on technical solutions to help buildings and infrastructure survive flooding, he says. But van Wingerden, who has a career designing floating buildings and in 2012 became CEO of the international floating construction development firm Beladon, wondered about food. Flooded roads and tunnels in parts of southern Manhattan, Brooklyn, and Queens hobbled much of New York’s food distribution, delaying truck-based food deliveries to wholesale distributors and retailers. Power outages shut down refrigeration systems and storm surges inundated supermarkets and bodegas, according to an assessment from the city of New York.

And it could have been worse: Sandy had hit when the tide was out, saving New York’s low-lying Hunts Point peninsula, home to one of the world’s largest food distribution centers, from disaster. But Hunts Point was vulnerable to future flooding. “That was the reason we thought, ‘Why not design something that is climate independent?’” says van Wingerden.

Back in Rotterdam, van Wingerden and his team got to work, designing a three-story farm that floats on pontoons, anchored to the seafloor by steel beams. Twice per day, tides raise and lower the farm by about eight feet. So far, Floating Farm has remained steady in 110-mile-per-hour winds, says van Wingerden, never tilting more than a foot to one side.

Mostly, the cows roam the main deck’s rubber floor — more comfortable than concrete. They drink rainwater collected from the farm’s roof and desalinated seawater, both of which are purified onboard the vessel. They watch for the robotic feed-belt system overhead to deliver a mixture of hay, grass clippings, and spent grains donated by local breweries. Behind the cows, a manure robot, developed for land-based farms in 2016 by the Dutch company Lely, traces a predetermined route around the floor, sucking up as much as 80 pounds of excrement every two hours.

Each cow wears a collar, also manufactured by Lely, with an electronic tag that uniquely identifies her and helps coordinate robotic milking. When a cow feels the urge to be milked, she voluntarily walks into the milking stall, where a sensor near her head reads the tag. If she’s due to be milked, the stall’s back door closes behind her and a bit of feed falls into a bin in front of her. As she eats, a 3-D camera tracks her motion, while a robotic, laser-guided arm sprays a sanitizing wash over her udders, and then attaches the milking mechanism. After six to eight minutes, the robotic arm retracts, the front gate opens, and the cow walks out.

The manure robot dumps the waste into a shaft to the deck below, where it’s compressed to squeeze out liquid. Remaining solids are used as fertilizer for city parks. A second process, currently being refined in partnership with scientists at Delft University of Technology, pulls nutrients, including nitrogen and phosphorus, from the urine. Those will be used as fertilizer, leaving behind only water.

Although the technology used on Floating Farm is also available to land-based farms and could help them become more efficient, van Wingerden says his primary goal has been to showcase a circular agro-economy in which cows eat local vegetables and garden waste and humans turn bovine excrement into a usable product for plants. Such a system closes a city’s nutrient loop by eliminating the need to ship in feed and store or dispose of animal waste. That lowers the carbon footprint of transportation and reduces the negative discharges of nitrogen into the environment, where it can pollute waterways.

“I think Peter’s doing a good job showing people what modern farming could look like,” says Adriaan van der Giessen, project manager for the City of Rotterdam Economic Development’s Team Food, which supports business growth around sustainable food solutions in the Netherlands’ second-largest city. Traditional farming isn’t popular among young people in the Netherlands, says van der Gieseen, but a floating farm, as well as other high-tech urban agricultural approaches like vertical farming of stacked crops, “attracts new and young people to the agro-food sector,” he says.

By land or by sea?

When van Windergen first proposed putting cows on the water, people joked that the animals might get seasick. City officials who handled his permit applications expressed concern about the odor. He was taken aback. “We are one of the biggest chemical ports in the world,” van Wingerden says now. “What do you mean about smell?”

Jan-Willem van der Schans, an expert in agricultural economy and a senior researcher at Wageningen University and Research, a university in the Netherlands, is also skeptical of van Windergen’s effort. He argues that the floating farm sends an unfair message that rural farmers in the Netherlands are not innovative and that land-based dairy is so dysfunctional, it needs a marine alternative. “It’s a platform signaling innovation, and some of the innovations are actually quite interesting, but to put them all together on a pontoon is kind of like … a theme park,” says van der Schans.

Historically, says van der Schans, circular economies characterized dairy farming in the Netherlands as far back as the 15th century. Farmers fed their cows spent grain and used the manure as fertilizer. So much of it was exported to the country’s coast that it turned the sandy soils of the Westland region into prime horticultural land. “These farmers were innovative already,” says van der Schans. If van Windergen used the floating dairy farm to educate visitors about this forgotten history with plaques or displays, van der Schans says he would better appreciate the effort. “It would restage and modernize this old story that nobody knows about,” says van der Schans. Still, he acknowledges, Floating Farm may provoke a debate about how cities can feed themselves as they grow.

That’s what interests van der Giessen of Rotterdam’s Team Food. He thinks Floating Farm doesn’t necessarily send a message for the Netherlands, where most farms are still small and family-run. Instead, he thinks Floating Farm’s example is most relevant for countries with megacities that exceed 10 million people, where land is scarce and food is shipped from distant regions. “We aren’t going to build hundreds of floating farms in the Netherlands, because we have very good production on the land,” says van der Giessen. “But the farm shows Asian cities or Middle Eastern countries that you can also produce food under totally different circumstances.”

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Tracy Staedter is a writer based in Milwaukee, Wisconsin.


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