Hexgardens in a Harsh Environment
After several years of working with experimental aquaponic systems, including the SPACE 200 and the Hi-SEAS X-30 systems, we began plans to build a system scaled to production volumes. To better understand the logistics for growing off-season produce in our region, we built a small demonstration system in our home shop. Our shop space has a fairly small footprint (12’ x 12’) with high ceilings (13’).
To capitalize on our headspace, we built the system to suspend from the ceiling which allowed us to conserve floor space for seed starting. Although this allowed us to make the most of the floor space, it turned out to be a dangerous and tedious arrangement for managing plants. To check on our crops, we had to climb a very tall ladder to see them and then climb down to move the ladder to check the next tower over. Although we saved space by building high, we were wasting a lot of time and energy due to inaccessibility, not to mention the safety risks involved with working on a ladder so often.
To solve this problem, Jeff implemented a winch system that raises and lowers the towers when we need check on the plants. There are still some balance issues to work out with the winch, which becomes messy when the rows are full of water. Perhaps we should have hung the towers at eye level from the beginning, but hopefully our mistakes will inform future developments.
We had some really interesting results with our Zero-G system. Basil grew quite well and definitely has potential for commercial production. Herbs are generally thought to do poorly in controlled environment systems. This is usually because the environment is too accommodating to induce the stresses required to stimulate essential oil production in herbs. Nonetheless, we were able to grow some very fragrant rosemary, basil and lavender. Perhaps the frequency of our LED lights helped stimulate essential oil production.
We also grew a few varieties of leafy greens, but they exhibited a very strange growth pattern of elongated nodes. I have read that this growth pattern occurs in soybeans when there is a non-ideal ratio of red to far red light used. The article stated that a certain threshold of blue light can remedy this problem. The next time we grow leafy greens I will try using a more complete spectrum. The leafy greens also had heavy issues with whiteflies and aphids. We didn’t see any insects on the herbs, probably because their essential oil production acted as a herbivore deterrence.
We shut the system down at the end of the winter when we started to focus our attention on outdoor crops. If we were to reboot the Zero-G, I would definitely want to adjust the aforementioned issues. But the most important change I would want to implement is USDA compliance practices so that we can feel more confident about the safety of the food we are producing.
We learned a lot and collected a lot of really great data with the Zero-G experimental system. We considered applying for the Growth Through Agriculture grant again this year, but when I was writing our proposal for a container sized production facility, I kept waking up in the middle of the night with a voice saying “Don’t do this!” After some soul searching, Jeff and I realized that we don’t necessarily want our lives to be about large scale crop production. We love to research, experiment and create. We decided to shift our focus and continue to experiment with controlled environment agriculture while sharing our experiences with the world.
With the 2017 Indoor Ag Con, Las Vegas fast approaching on May 3rd and 4th, we would like to look back on our experiences from the 2016 Indoor Ag Con (IAC). Like many small farmers, we don’t have a huge budget to hit every conference, but it has been well worth it to attend when we are able. In 2016 we attended the IAC conferences in Singapore and Las Vegas, where we were able to meet interesting industry professionals and researchers. It was inspiring to learn about the newest and coolest tech coming out in this rapidly changing field.
Although we have no plans to participate in the Asian vegetable market (that’s quite the antithesis of local foods!) we saw the IAC in Singapore as a very valuable educational experience. Indoor agriculture has had a bit of a headstart in Asia, and we hoped that attending the IAC in Singapore would give us some insight into the future trajectory of the indoor agriculture market in the US.
The reason Asian markets are ahead of the curve is partially due to popular interest in sourcing food that has not been affected by pollution. This is especially true in Japan, where apprehension regarding the effects of Fukushima fallout in soils has engendered a higher value for crops grown using a type of controlled environment agriculture (CEA) referred to as plant factories with artificial lighting (PFALs). Because these consumers are willing to pay a premium for PFAL grown crops, the market is more developed in Asia than it is in the US.
Kozai’s take home message was quite surprising, if not slightly off-putting to investors. Currently, only 30% of PFALs are making a profit; 20% are losing money and 50% are just breaking even. After dropping this somewhat discouraging information, Kozai went on to discuss many of the often overlooked variables that impact the delicate profit margin in PFALs. Of particular importance is the photosynthetic rate which is set by the availability of carbon dioxide. Many of the PFAL operators who were failing to turn a profit were not aware of this aspect of plant biology and had not been implementing carbon dioxide supplementation.
Another important factor that is a bit more obvious is resource use efficiency (RUE), i.e. the weight of marketable crop produced compared to the energy resources that go into growing it. One thing that I thought was kind of interesting about RUE is that a lot of energy goes into cooling PFALs because so much waste heat is generated by lights and pumps. I had thought that it would take more energy to run a PFAL in a cold climate because there would be a cost to heating the indoor environment, but this is actually not the case. Instead, RUE is arguably higher in a cold climates because incidental heat from lights and pumps passively heat the indoor environment. In cold climates, excess heat can easily be released to the outside environment, therefore eliminating the need to expend energy on cooling the inside environment.
Another important metric to consider for RUE is the root to leaf ratio of the crop. This is because energy resources go into growing the entire plant, including the often unsellable root biomass. That can be considered wasted profit. Kozai advocated for focusing on crops where all parts are eaten, including the roots. There are a lot of high value medicinal chinese herbs that fit into this category.
Kozai also spoke on the need for open access to information, because PFAL operations are very competitive right now but they could be much more successful if they were collaborating. This is why the OpenAg Initiative at MIT is so important.
After his talk, Jeff was very excited to meet Dr. Toyoki Kozai and we immediately went on Amazon and ordered his book, Plant Factory. It is very well put together, although a bit on the academic side. I prefer that style of writing sometimes. It may be more difficult to get through, but the information is more specific and therefore more easily applied.
Dr. Eiji Coto from Chiba Horticulture discussed using environmental controls to maximize crop quality. The problem with PFAL conditions is that they are too perfect for plant growth. As a result, the lack of stress prevents the formation of nutritional compounds like antioxidants. Coto reminded us that although blue light induces antioxidant production in crops, it also requires more energy to run this type of grow light. However, Coto was experimentally able to show that finishing crops with a short blue light period towards the end of their growth cycle induced production of antioxidants.
IAC Las Vegas was very different from IAC Singapore. It seems like the CEA industry in the U.S. is a much more diverse beast than the predominantly PFAL juggernaut taking over in Asia. At IAC Las Vegas, we heard from a lot of companies providing mini-PFAL container farms for the small farmer, a paradigm which was not really as relevant at IAC Asia. Another huge difference was the effects of the U.S. cannabis market on CEA. This cash crop seems to be the main driver of the CEA industry in our country.
Eric Amyot from Modular Farms spoke about the fact that most of his customers do not have much experience farming. Because of this observation, his business model has directed energy towards empowerment and education of container farm owner-operators. This is aso a huge part of the philosophy behind Bright Agrotech, a well established company that produces vertical grow towers that are used in many container farm companies. Kyle Seaman from Freight Farms reiterated that container farm crop failure is very often the result of user error and inexperience. For example, top two very popular crops are lettuce and basil, however they require very different environmental conditions. Often inexperienced growers will try to split the difference which reduces quality and productivity overall. A better solution would be to invest in a second container farm and dedicate each container to the specific conditions for the crop within.
We asked Dan Kuenzi from Local Roots about the future of automation in container farms. He very wisely responded that moving parts inherent to automation are really just a liability because they will always require maintenance. Container farm owner-operators are different from large scale PFAL operators because being small scale means they often don’t have the resources to be both farmers and automated robot mechanics. He argued that the less automation a container farm possesses, the less vulnerable it is to breaking. We thought this was a very interesting point to consider for space farming as well. Being so far from new parts, space farmers will probably be better off if their CEA systems are designed to be easily fixable. The more DIY an operation is, the more likely a problem can be easily remedied and high tech often translates to complicated problems.
We are pretty interested in the idea of insect farming, especially for space travel. The conversion ratio from inputs to consumable products is very efficient in insects and their biomass is very high in fat and protein. We were fascinated by the talk from Andrew Brentano of Tiny Farms. He told us that there are currently about 40 insect protein based products on the market and this demand has been doubling every year, especially in products for human consumption. Another really great point he made about insect protein is that it is less likely to contain environmental toxins that often accumulate in larger, longer living animals.
Dr. Neil Mattson from U.C. Davis gave a mike drop presentation on data compiled by researchers at Cornell University regarding the carbon usage of CEA systems compared to traditional field crops. I agree with Mattson’s sentiment that energy is the last frontier in CEA because although we have made many efficiency improvements recently, the carbon footprint for CEA is still too high. To offset this difference, he argued that we need to increase productivity by 4 fold. He suggested several biotech mechanisms for accomplishing this increase in productivity.
Mattson reminded us that food waste in the U.S. is currently up to 40% and suggested a few solutions. He mentioned that storing lettuce with bit of water and their roots in tact increases the shelf life 17-26 days. Of course, there is a tradeoff to consider that includes not only production of the package, but disposal as well.
Furthermore, he suggested genetic modification of foods as a way to increase their shelf life. I’m not sure what part of the genome could be affected to create a slow decay crop, but I feel like there might be an intrinsic correlation between nutrient availability and the ephemeral nature of food. If this feeling has any merit, it leads me to wonder if foods that resist breaking down in the presence of microbial contamination are also less likely to give up nutrients in our bodies as well.
Everyone was eagerly anticipating the final speaker, Alison Kopf, CEO of Agrilyst. Agrilyst is a big data farm management platform that tracks conditions on your farm and provides relevant alerts that allow you to adjust environmental controls for optimizing crop productivity. This made me realize that it one thing to have fancy sensors, but it is quite another thing to understand what to do with the data they collect. We enjoyed her talk very much and look forward to seeing their business grow.
The lineup for Indoor Ag Con, Las Vegas 2017 looks very interesting. We are particularly looking forward to hearing from food safety auditor Sarah Taber who will be talking about health and safety considerations for start-up farmers. This is a topic that I have wondered about, but have not found the most direct information through the USDA website. We are also looking forward to learning about new developments in technology for CEA systems. Representatives from Autogrow and Bright Agrotech will be participating in a technology panel on the first day of the conference, and Dr. Shao Hua Li will give an in depth talk on the latest developments in CEA on the second day of the conference. Also on the second day, there is a discussion session dedicated to indoor mushroom grow operations. We love growing mushrooms in our small system and look forward to hearing from industry professionals on this topic. It will be a great conference and we hope to seeing you there!
by Melissa Pernell
Space farming research can help us improve controlled environment agriculture (CEA) systems so we can grow our food in a more resource conservative manner.
The International Space Station’s model of food production has a lot in common with how we ought to design our food distribution systems here on Earth. Interestingly, support for centralized food production in cities in gaining a lot of traction through the local foods movement. That is because people understand that growing food close to consumers uses less fossil fuels than growing food in the countryside and then shipping it into the city.
However, recent studies show that this is not entirely true: It is still more energetically expensive to grow food locally with CEA in city centers, but not by much. If current trends in renewable energy continue, it will soon cost less energy to grow food indoors using artificial lighting and high tech environmental controls than to ship food from traditional agricultural areas. Because of NASA’s research on light emitting diode (LED) technology, we now have energy efficient grow lighting available for agricultural use. The development of LED lights was motivated for space exploration, but the improvement and application of this technology has made CEA economically possible.
Before LEDs, indoor growing systems required obscene amounts of energy with grow lights like metal halide and high pressure sodium, meaning that only growing cash crops like marijuana could be economically feasible in these systems. With improvements in LEDs, we are just now starting to hit the economic/technological threshold where we are beginning to see the proliferation of CEA operations within cities. These systems are being built in populated areas close to consumers, conserving the fossil fuels currently used to ship produce across the country. With inevitable improvements in solar grid technology, these city-based CEA systems will soon use far less fossil fuel energy than shipping produce in from rural areas.
Even with the current energy costs of CEA, these systems are still more ecologically sustainable than soil based agriculture. Soil erosion is an unfortunate consequence of our current intensive agricultural paradigm and this is especially true for the annual crops that require soil disturbance for planting and harvesting. In contrast, CEA systems are predominantly hydroponic, which means that the soil that would have been used to grow that annual crop can now instead be devoted to perennial trees and shrubs which are able to capture carbon and rebuild farmland soils.
Some farmlands can even be left fallow to return to the complex forest ecosystems that can fix far more carbon and house a wider diversity of wildlife than is tolerated in farmland ecosystems. This is an important concept to consider when we think about habitat destruction and carbon release that occurs as a result of traditional soil based farming practices. CEA makes possible a paradigm shift that will solve several environmental issues all in one shot.
However, the source of nutrients for hydroponic CEA systems is seldom discussed. The nitrogen used in hydroponics relies on the Haber-Bosch Process, an energetically expensive method for fixing atmospheric nitrogen into a form that is usable by plants. Furthermore, the remaining mineral nutrients used in hydroponics are obtained from mining which causes habitat destruction and toxic run-off. Not only that, but the supply of these minerals is limited. For example, it is estimated that there are about 40 years left of mineable phosphorus stores available. After that, the only source left will be the phosphorus derived from animal waste.
There is a very necessary impetus to understand how to recycle plant nutrients from waste in a safe and sustainable manner, rather than depleting our natural resources by continuing to extract new resources. Fortunately, much of the research on nutrient cycling is funded by studies aimed at understanding these processes for application in space colonization. The holy grail of this research is the development of a resilient and truly closed loop ecosystem. Transforming waste into food in a closed system is the alchemy we need to master in order to make it over the first hurdle of self sufficient Martian colonization.
By creating CEA systems that function independently from nature, like we aim to do during space colonization, we are removing the pressure that we have imposed on Earth’s ecosystems when we converted so much forest and prairie into farmland. When annual crops are grown indoors, close to consumers, the farmland that was once used in a soil depleting way can be dedicated to growing perennial trees and shrubs that contribute to soil building, water table stabilization and carbon sequestration.
Two summers ago I was working for the USDA doing a soil survey at Glacier National Park. While in the field, I told the soil scientists I was working for about our aquaponics project at the University of Montana Dining Services, SPACE 200. The next summer, they told their new field assistant Carmel Johnston about our project. Johnston asked the USDA soils crew to connect us because she had hoped to bring an aquaponics system with her on her next project. Johnston was selected to be commander of Hi-SEAS, a yearlong Mars simulation funded by NASA through the University of Hawaii. The Hi-SEAS mission is to study the physiological and psychological effects of isolation on a small group of space settlers. Being a soil scientist and gardener, Johnston had hopes of bringing an aquaponics system into the simulation for her and her crew to grow fresh vegetable during their year of isolation. She had a hunch that having plants on board would confer a positive effect on crew morale as well as her own. When she asked if we would be interested in building an aquaponics system for the Hi-SEAS mission, we were absolutely thrilled to help her out.
Within a week we met up with Johnston to discuss experimental design and the constraints that she would be facing in the Hi-SEAS dome. We decided to build 4 small 30 gallon systems (the x-30s); 2 would use fish effluent and 2 would use human urine as a nutrient source. Unfortunately, there were problems getting fish for the systems due to Hawaii’s strict regulations regarding live fish transport. In the end, the crew was only able to use human urine as a nutrient source, which actually had decent results.
Besides not being able to use the fish we had planned for in our experimental design, there were energy issues to contend with as well. We knew going in that power would be limited, so we selected very low energy usage LED lights. Johnston coped with this limitation by selecting low light requiring plants to grow in the systems. However, the power available to the LED lights was through solar DC power, and therefore was too inconsistent to meet the needs of the plants. Johnson dealt with this by keeping 2 of the systems near a window to receive to available sunlight from outside.
Ultimately, Johnston and her crew were able to successfully grow peas and chard, although at low production levels. Although the systems were not as productive as they would have been if there were fewer limitations, the crew reported that working together on the project had value in terms of psychological benefits. The psychological effects of the astronaut diet were addressed in depth when the Hi-SEAS crew was interviewed for a recent podcast on Hidden Brain. They reported that much of their time is spent thinking about food because their options are so limited. Previous research has shown that astronauts often become bored of their limited food choices and then stop eating as much as they need for optimal health. The theory here is that humans are foraging omnivores and we are evolved to desire a certain level of variety that helps to ensure that we consume the diverse set of nutrients we require. For the crew of Hi-SEAS, having the novelty of fresh vegetables, even if only on special occasions, really helped them feel excited about meals during their year of living on preserved astronaut food.
Galactic Farms was very excited to have been able to participate in the Hi-SEAS project. It was a lucky happenstance that we connected with Carmel Johnston through our USDA friends. Our luck continued when one of Johnston’s crew members, astrobiologist Cyprien Verseux, sent us a very interesting review article he and his colleagues wrote on the potential for using cyanobacteria as a way of extracting nutrients from undeveloped rock dust (regolith) found on Mars. This seemed like a pretty interesting thing to look into and inspired us to start a cyanobacteria culture at Galactic Farms. Furthermore, the Verseux paper was the foundation for our submission to the Mars City Design competition, where we were able to place first in the agricultural section of the contest. For more details on this project, click the link: