When form beats function: Plant-scrapers and indoor growing

Kristen 1 4This entry is from Kristen Bastug, a senior Biology major at the University of St. Thomas.

The global agriculture system has benefited from technological advances, and scientists and farmers continue to search for ways to combine technology with agriculture to feed increasing numbers of people. Examples can be seen across the globe: Japan hosts an indoor lettuce farm, vertical farming takes place in Singapore, and hydroponic rooftop gardening can be found in New York. Many countries in Europe, such as Sweden, contain buildings designed with agriculture in mind. These “plant-scrapers,” shown below, serve to produce food and are aesthetically pleasing, attracting outside visitors in a process known as agro-tourism. These innovations are trendy, but trends are not always practical.

Swedish-American company "Plantagon” breaks ground in Linkoping, Sweden with plans to build multiple plant-scrapers in the future. (http://inhabitat.com/plantagon-breaks-ground-on-its-first-plantscraper-vertical-farm-in-sweden/)

Swedish-American company “Plantagon” breaks ground in Linkoping, Sweden with plans to build multiple plant-scrapers in the future. (http://inhabitat.com/plantagon-breaks-ground-on-its-first-plantscraper-vertical-farm-in-sweden/)

Plant-scrapers exemplify a technological advance to the food production system that is an entertaining but unrealistic solution for feeding the world. This is a daunting task in itself, as current food production must double by the year 2050 in order to meet future need (Foley et al. 2011). Plants require soil, water, and sunlight to grow, all of which must be supplied to an indoor setting. The most costly of these is providing enough light, which is passively obtained in an outdoor setting. If vertical farms were used to produce a year’s amount of wheat in the United States, running only the lights would require eight times as much electricity as the nation’s current utilities can supply in a year. This would only free up 15% of the nation’s cropland. Growing corn in the same manner would require 40 times the nation’s energy. Even growing just vegetables indoors would necessitate the doubling of the current power supply, and this would only free up 2% of crop land. These numbers don’t consider the energy required for climate control either, such as heating in the winter and cooling in the summer (Cox and Tassel 2010). Examining these inputs discredits the idea that vertical farming is an efficient use of space and resources. Agricultural solutions must be sustainable and scalable, neither of which apply to indoor growing.

Artificial trees in Singapore attract visitors to the island. (http://www.redicecreations.com/ul_img/20838supertreesC.jpg)

Artificial trees in Singapore attract visitors to the island. (http://www.redicecreations.com/ul_img/20838supertreesC.jpg)

The danger of promoting unrealistic growing methods is a resulting decrease in appreciation for large scale rural farming. The majority of the world’s food is generated this way, and incorporating traditional forms of agriculture into the urban environment is an alternative way to bring agriculture to the city without building high-input indoor systems. An analysis of Cleveland, Ohio found that using vacant lots, residential lawns, and hydroponic gardening on industrial and commercial rooftops can supply up to 100% of the city’s fresh produce need (Grewal and Grewal 2012). Additionally, outdoor urban agriculture can help reduce the urban heat island effect, mitigate storm water impacts, and lower the amount of energy that goes into food production (Ackerman et al. 2014), benefits that are lost when agriculture is moved indoors.

Plants grown in an indoor setting require an artificial source of light (http://2.bp.blogspot.com/-9QxCq9skL_A/U9Dc_lT2HsI/AAAAAAAACP0/ICf7Cw4TDI4/s1600/vericle-farming.png)

Plants grown in an indoor setting require an artificial source of light (http://2.bp.blogspot.com/-9QxCq9skL_A/U9Dc_lT2HsI/AAAAAAAACP0/ICf7Cw4TDI4/s1600/vericle-farming.png)

While plant-scrapers may not be a global solution, they do help increase awareness about sustainability issues. An indoor growing facility is intriguing and can help city dwellers reconnect with the natural world. The United Nations reported that 54% of the world’s population currently lives in cities, and this is expected to rise to 66% by the year 2050. Currently, the world contains 28 megacities with populations of over 10 million people; this number is expected to increase to 41 megacities by the year 2030, less than 6 years away. Inspiring urban dwellers to consider global food issues is therefore important, and urbanites may be inspired to start their own gardens upon seeing a beautiful plant-scraper. Plant-scrapers should not be viewed as the way of future farming, but seen as one way for a city to generate food with a limited amount of space.

Demanding forms of agriculture that can help feed the world in a sustainable manner is more important than demanding a flashy, futuristic form of farming that is less efficient. Incorporating plant-scrapers into cities should be done with the knowledge that these buildings contribute to the local food supply, but come at a cost and are not scalable on a global level. We must acknowledge the reality of our global state of agriculture and demand practical solutions; nature has mastered both form and function and we should strive to do the same.

UST Environmental Science students in national sustainability competition

The blog has been on hiatus for a while, partly because we’ve had so many exciting things going on.  One of our current projects involves investigating the feasibility of using hydroponic gardens to improve water quality in a local urban lake (Saint Paul’s Como Lake), turning a waste product (nutrient pollution) into a product of value (locally grown food).

The rationale is simple: many of our urban lakes suffer from excess phosphorus, which comes from our lawns and gardens, pet waste, and leaves.  Phosphorus is necessary for all life–it serves as the backbone of DNA, for example–but in lakes it fuels the growth of excess algae.  The decomposing algae can use up a lake’s dissolved oxygen, causing fish kills, and algae-covered lakes are less desirable for recreation.  Many different initiatives have focused on reducing phosphorus inputs to Como Lake, through increasing stormwater infiltration (through rain gardens or underground trenches) and from neighborhood leaf cleanup initiatives.  While these initiatives have reduced P inputs, the problem is that there is a huge amount of phosphorus stored in the lake sediments, which is the main contributor to lake water phosphorus.  To achieve any improvement in lake water quality, somehow we have to address this hidden source of phosphorus to the lake.

My students and I have conducted experiments with our 600-gallon aquaponics system for the last few years, in which vegetables grow hydroponically while removing nutrients from fish waste.  We wondered about using similar technology to clean urban lakes, and received a grant through EPA’s People, Prosperity, and the Planet Student Design Competition for Sustainability.


Last summer Jessica Brown conducted the first phase of this work, funded by a Young Scholars grant through the UST Grants and Research Office.  Jessica’s study focused on measuring the maximum rates that different plant species could remove phosphorus from lake water, and on identifying limitation by other nutrients (like nitrogen and iron) that limit plant growth in lake water.  Her research showed that legumes (such as peas and beans) can partially compensate for low nitrogen in the lake water by “fixing” atmospheric nitrogen, but the plants require additional nutrition to thrive.  Currently my Environmental Problem Solving class is designing an experiment to find the best solution to this problem.  The class will also be exploring the effects of hydroponic gardens on lake water quality by building on the lake ecosystem model begun by research student Quinn Niederluecke.

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Results from Jessica Brown’s study measuring the amount of phosphorus that could be sequestered in different types of crops growing hydroponically in urban lake water.

In mid-April, a team of our students will travel to Washington D.C. to present our project at the National Sustainable Design Expo and compete for a Phase II award.  We’ll be posting updates on the project periodically throughout this semester.

The End of Growth? Perspectives from an Aquinas Honors seminar

“Questioning (economic) growth is deemed to be the act of lunatics, idealists, or revolutionaries. But question it we must. The idea of a non-growing economy may be an anathema to an economist. But the idea of a continually growing economy is an anathema to an ecologist.” – Tim Jackson, Prosperity Without Growth

‘Supertrees’, Singapore. Photo credit: Wikimedia Commons

‘Supertrees’, Singapore. Photo credit: Wikimedia Commons

Conventional economics is based on the assumption that the environment is merely a subset of the economy, resources can be infinitely substituted for one another, and human population growth and consumption can continue indefinitely. Growth is held out as the elixir for our social and economic ills such as unemployment, poverty, and the staggering government and private debt. In an age of rising energy costs, a changing climate, land use degradation, and an ever growing population, the importance of ecological consequences of economic growth are becoming increasingly obvious. This semester, Jim Vincent (UST Economics) and I lead an Aquinas Honors seminar to discuss relationships between economic growth and the environment. We asked our 12 students to write essays on an issue of their choice that integrated themes from Ecology and Economics.

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Masdar City: Oasis of Sustainability, or Just a Mirage?


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Can a city be truly sustainable?  In a 2012 paper, ecologist Robbie Burger argues that even Portland, Oregon, widely considered to be the “greenest” city in the United States, falls far short of true sustainability.  Despite the city’s farmers markets, bike trails, and public transportation, Portland’s per capita fossil fuel consumption was not much different than that of the average U.S. citizen.  Portland, like all cities, is intrinsically embedded within the larger, unsustainable, global economy.

Cities are like organisms: materials and energy come in and get processed, and waste products result.  In my Urban Ecosystem Ecology class, we’ve been digging in to studies of urban metabolism.  There are fundamental similarities across these cities, such as major CO2 fluxes generated from transportation and electricity production.

We came across an interesting, and very different, example in Masdar City, a planned sustainable city/research campus on the outskirts of Abu Dhabi.  While the United Arab Emirites is a leading oil producer, Masdar is powered by a massive 100 MW solar array, and built with passive technology to minimize the energy demand for cooling.  It’s also a car-free city, where futuristic driverless cars transport people between underground stations.  Labs in Masdar conduct research on renewable energy.  Masdar City has won accolades from various environmental groups, and is supported in part by the U.S. Department of Energy.


Masdar City under construction in 2012. Source: Wikimedia Commons.

Is Masdar City truly a sustainable city?  Yes, the city’s carbon footprint is remarkably small (although not zero, as initially planned).  Sustainably harvested palmwood is used in construction, and greywater is planned to be used for crop irrigation.  On the other hand, currently the “city” only has around 4,000 residents (plans are for the population to grow to 50,000 in coming years).  There are no gas-burning cars in the city proper, but many workers commute from nearby Abu Dhabi.

What raised the biggest red flag for me, from the video we watched, was seeing the CEO of Masdar, Dr. Sultan Ahmed al Jaber, explain why Abu Dhabi is trying to become a leader in sustainable energy production, despite its oil riches.  He explains that the emirate loses money with every barrel of oil that it uses domestically rather than exporting.

If the ultimate goal of this “sustainable city” is for more Middle Eastern oil to be burned in the United States, that doesn’t bode well.  That’s like a city shutting down its local power plant, and instead importing electricity from a more distant plant, and claiming to have drastically cut its CO2 emissions.  It might look good on paper, but it accomplishes nothing.  Robbie Burger’s argument was that sustainability must be considered in a holistic sense–there is no validity in walling off a city (either figuratively, or, in the case of Masdar City, literally) and proclaiming it to be sustainable.  Climate change is a global problem, and externalizing pollution to achieve local-scale sustainability is little more than a marketing ploy.  On the other hand, if Masdar City’s model of government-owned, profit-driven sustainability research drives innovations that gain traction and become widely accepted, perhaps there are real benefits.

Aquaponics Update


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As winter continues its grip on Minnesota, a tropical river ecosystem is thriving inside the OWS greenhouse.  We started last spring with a small-scale experiment, asking how efficiently we could turn food waste into worms, worms into tilapia, and tilapia waste into basil.


Last summer we started up a 600-gallon aquaponics system where we grew a crop of tomatoes, and now we’re growing kale and basil.  I also started a collaboration with Healing Haiti, an aid organization that runs a commercial-scale aquaponics system in a village near Port-au-Prince.

Students in my Urban Ecosystem Ecology class are currently constructing an ecosystem model using STELLA software, based on our data from the small experiments, the larger greenhouse system, and the giant system in Haiti.  Our goal is to create a management tool that will help managers run the Haiti system more efficiently, thereby increasing the capacity for food production in the poorest country in our hemisphere.


We’re also kicking off a new experiment with the six smaller aquaponics systems, involving freshwater shrimp (Macrobrachium rosenbergii).  We’ll be growing shrimp and tilapia, separately and in combination, to measure overvielding–i.e., do we get extra animal production per unit of food added in the higher biodiversity treatments?

The shrimp have arrived and are settling in to their new homes.  Unfortunately, with the cold weather, our new tilapia have not been shipped from their home in south Florida.  Hopefully they’ll ship in a few weeks and we’ll get started.  Stay tuned for details.


Scientists stepping out of the ivory tower

This week I read a pair of remarkable articles on scientists who have stood up against industry.

The first piece, in the Feb. 10 edition of The New Yorker, profiles UC-Berkeley toxicologist Tyrone Hayes and is decade-long battle against agrochemical giant Syngenta regarding the credibility of his research showing that trace amounts of the herbicide atrazine can cause hermaphrodism in frogs.  Recent documents reveal the extent to which the company deployed legal and communications teams to attempt to discredit Hayes. 

The second article, in the Feb. 7 edition of Science, profiles University of Maryland ecologist Margaret Palmer, whose research on stream restoration has led to her frequent appearances as an expert witness in court battles over mountaintop removal mining in West Virginia (and even an appearance on the Colbert Report!).  The article documents examples of cross-examinations that verge on personal attacks, yet the naturally-introverted Palmer has remained unflappable.


The landscape of much of West Virginia has been altered through mountaintop removal, prompting University of Maryland ecologist Margaret Palmer to become engaged in legal battles. Photo: Wikimedia Commons

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On not seeing the forest for the trees (or the watershed for the lake)


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One lesson I try to get across to my students is the importance of thinking about environmental problems from a holistic perspective.  Otherwise, focusing only on one part of a problem can inadvertently worsen other problems (some interesting examples described in this article by Emily Bernhardt).

One problem that I think about a lot (as do many other Minnesotans) is the issue of nutrient pollution in lakes.  The classic lake management success story is Lake Washington, near the city of Seattle.  During the 1940’s and 1950’s, eleven sewage treatment plants were discharging nutrient-rich treated wastewater directly into the lake.  The fertilization of the lake resulted in massive blooms of blue-green algae, and led to fish kills.  Based on years of data collected by the limnologist Tommy Edmondson at the University of Washington, phosphorus was identified as the culprit, and a series of expensive engineering projects eventually re-routed the wastewater discharge directly into Puget Sound, bypassing the lake.  Over the ensuing decades, water quality improved, and the lake is now twice as clear as it was in 1950.

Something about this story has always bothered me, though.  Puget Sound has its own problems with nutrient pollution.  Shunting pollution further downstream is an awfully narrow definition of success.  Every ecosystem is embedded in a larger ecosystem.  Sustainability requires considering the whole, not just one of the parts.

I was reminded of the Lake Washington story by an article that my mother-in-law sent me recently, about Jordan Lake, a reservoir in my home state of North Carolina.  This reservoir is a popular recreation spot near Raleigh (I used to kayak there) and provides drinking water for more than a quarter of a million people.  And, like many lakes near urban areas, it has suffered from nutrient pollution and algal blooms.  To address this problem, the state has imposed strict limits on nutrient runoff throughout the lake’s watershed, a policy that some in the business community have argued is costly and ineffective.

The state is now shifting gears and trying a completely different approach by installing 36 solar-powered pumps throughout the reservoir to circulate water.  The idea is that by mixing water from different depths, algae will not have enough light to survive, despite the excess nutrients.  The proponent of this plan is a former toxicologist for the EPA, who now works for the company that makes these pumps (and is leasing them to the state for $1.4 million for the next two years).  As part of this plan, the state will ease regulations on nutrient runoff.

There’s plenty of politics at play here.  The GOP controls the state government now, and is happy to loosen environmental regulations that it considers to be expensive and ineffective.  State Senator Rick Gunn, who led the rewrite of the environmental program, claims that high nutrients alone are not a problem.


After years of problems with excess nutrients leading to algal blooms, the state is trying a different approach by installing solar-powered pumps to mix the lake water–while easing restrictions on nutrient control. Image: Wikimedia Commons.

These pumps have been deployed in several other lakes around the country, with mixed results.  Will they work here?  Maybe.  I think it’s an interesting experiment.  But the part about easing nutrient restrictions–that gets back to the Lake Washington problem.  The thing about rivers is that water moves downstream.  Even if the pumps work perfectly and prevent algae blooms in Jordan Lake–and that’s a big “if”–these excess nutrients are going to flow into, and out of the reservoir, and on down the Cape Fear River, eventually reaching the coast where they undoubtedly will cause problems.

This is a case of treating the symptoms and ignoring the underlying problem.  Sometimes you need to pay attention to both–and that requires looking at the big picture.

Are we in for a hard landing? Professor Tom Hickson thinks so.

Dr. Tom Hickson, of the UST Geology Department, sent me the following post last week, just as the government shutdown ended.  -cs


Maybe a soft landing is too much to ask for? Source: Wikimedia Commons.

Thank you, Tea Party?  

As the government shutdown comes to a close, as the U.S. temporarily averts a default on its debt, some nagging thoughts are floating around in my mind.  They are half-baked.  I’m not an economist, so they could be fatally flawed or screwy.  Here’s the gist of my internal ramblings:

The U.S. is the consumption leader of the world, with China and India racing to meet us.  World population continues to grow.  We hurtle toward an unsustainable future and the powers that try to impede this headlong rush are tiny compared to those that drive us on.  How much progress have we made in reducing oil consumption?  Have we reduced greenhouse gas emissions or are we on any sort of path to do this in the near future in any meaningful way?  Agricultural practices globally put our soils at substantial risk.  And yet growth is the economic panacea, essentially unquestioned except by a narrow and tiny group of academics and Occupy Wall Street supporters (I know there are more; I’m being testy here).  An unquestioned reliance on economic growth is absurd when thermodynamics dictates that there is no free lunch.  Resources are finite, so growth is limited.  This seems like a no-brainer to me. 

So, if we are to achieve a sustainable economy, we must limit growth in terms of some combination of population and consumption.  Am I missing something here?  But if powerful forces insist on growth to make economies function, how can these forces be curtailed?

Certainly one answer is through gradual social change, the political process, education, and a hoped-for enlightenment that will make us eager to live simply, to contract.  Right.

 Another answer is through global recession or depression.  Let the U.S. default on its loans, many of which are held by China, Japan, Germany, and other nations that like their consumption just fine.  Let the U.S. drag the world into economic collapse.  My guess: consumption would plummet.  All of sudden it’s sexy to carpool and bike to work.  Prius sales go up.  People start planting gardens to feed themselves.  Maybe even corporations would feel the pinch if the collapse were big enough. 

I’m just wondering: is the soft-landing possible or should we just go for the hard landing, bite the bullet, suck it up, whatever.  Would a more sustainable society rise from the ashes of this economic cataclysm? 

Love to hear your thoughts.

Critical Science


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One interesting aspect of the government shutdown is that it allows us to see how our elected officials prioritize different functions of government.  This is playing out today as Republican House members propose restoring funding to more popular pieces of government.  National parks and museums?  Sure.  Cancer research?  Alright.  Don’t forget to pay our National Guard Members, and benefits for veterans.  


The shutdown also forced government agencies to differentiate between critical and noncritical operations.  This week in our Biology of Sustainability labs, our students are beginning a study of the effects of environmental estrogens on fish in the Mississippi River.  When we tried to access a comprehensive U.S. Geologic Survey study on endocrine-active chemicals from wastewater treatment plants throughout Minnesota (on which UST Biology Professor Dalma Martinovic is a coauthor), we discovered that the website was down.  In fact, only those USGS websites “necessary to protect lives and property” are currently accessible.


What makes the cut?  Coastal erosion, earthquakes, volcanoes, landslides, and geomagnetic activity all have operational websites with tools, maps, and real-time data.  Synthetic chemicals in our rivers and lakes–and ultimately in our drinking water–that are turning male fish into females?  That can wait, apparently.


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