According to Wowryk, shipping challenges have been one of the biggest hurdles over the last year.
Photo courtesy of Nature Fresh Farms
Produce Grower: What logistical challenges has the last year presented?
Ray Wowryk: The largest disruption we experienced this past year has been airfreight. With the reduction of flights from growing regions such as Israel, Spain, and the Netherlands, overall supply during off peak production within North America has reduced supply access. At major border crossings, we have experienced sporadic truck shortages with elevated rates and delays on destination arrivals. Port delays in [Los Angeles] have caused delays of packaging materials, adding additional challenges to the farm and for packaging facilities in all areas of the industry.
PG: Are any of the changes this year permanent or are they likely to go back to the old normal when everything, at least in some ways, moves past the COVID-19 pandemic?
RW: Greater focus on food security will continue as consumer’s interest in local and a desire to know more about how their food is grown. All forms of protective agriculture are in a growth mode and those who can leverage innovation and scale production to remain competitive will be the new normal of the future of agriculture.
PG: Has there been any added or unexpected opportunity for businesses like Nature Fresh based in North America in filling gaps created by the delays in product sent from overseas?
RW: A shift in consumer shopping habits along with fewer shopping trips and home delivery has influenced all products packaged. The ease of filling home delivery orders and consumers buying more value added, fueled by the healthier lifestyle trend, has had a positive growth impact. This has not affected our bulk offerings at all, and we have seen growth in line with all industry reports on tomatoes, cucumbers as well as bell peppers.
PG: For Nature Fresh specifically, how has the organic category grown in the last year or so?
RW: Over the course of the pandemic, we have seen organic sales rise. As families grew accustomed to cooking at home during lockdowns, more consumers were out purchasing fresh products to cook with. We believe organics will continue to surge as more consumers look for healthier options.
PG: What does the market look like over the next year?
RW: We believe, now that at home cooking has made a return, we will see people purchasing more fresh products to cook with and looking for more ways to make homecooked meals, looking for recipes and preparation ideas to go towards a healthier lifestyle.
HR for vertical farms: How COVID, CEA’s high-tech focus have changed hiring
Features - human resources
A recent webinar explored ways that vertical produce farms – one of ag’s hottest segments with young people – can successfully attract the talent and expertise needed for long-term staying power.
Fifth Season (Pittsburgh, Pennsylvania) is in a great location for recruiting “horti-curious” employees with solid applied technology and engineering backgrounds.
A recent webinar presented by Indoor Ag Conversations (indoor.ag/webinar/) detailed creative and fresh approaches for attracting talent in one of agriculture’s hottest segments: vertical indoor farming.
Featuring representatives from some of the highest-profile vertical farming operations around — AeroFarms (Newark, New Jersey), Fifth Season (Pittsburgh, Pennsylvania) and Kalera (multiple sites across U.S. Southwest) — the panel discussed how hiring practices have shifted, morphed and evolved in the controlled environment ag universe.
“To me, the crux of the entire vertical farming industry is this unique intersection of agriculture and technology with hiring that means finding the candidate with the horticulture background and the technology expertise,” says Brac Webb, Fifth Season’s co-founder and COO.
Finding the right talent
MaryAlice Feinstein is AeroFarm’s chief people officer, heading up human resources for the world’s largest vertical produce farm by gross output.
Feinstein says that casting a wide net and being data-driven are two guiding principles for her recruitment efforts for the massive, East Coast-based B Corp.
“Diversity and inclusion in our hiring practices [are] super important to us, so the wider the net we can cast, the better,” Feinstein says, noting the success the vertical farm has found in recruiting former interns to fill permanent, full-time roles.
“We are committed to keeping those internships going even during COVID, and it’s paid off and been really successful,” she adds. “We’ve also sponsored and had good success with some regional incarceration re-entry programs. It’s something we’re super proud of.”
And when the steady open-spigot stream of compelling candidates slows to a trickle, it is time to deep dive into your data — your own website data, social media data, etc. — and see where good candidates have come from in the past, and double back to those sources, she advises.
Kalera’s Keri Gasiorowski, chief human resources officer, says a well-rounded recruiting effort should leave no stone unturned, even if that “stone” turns out to be the local food truck lunch meet-up spot down the street.
“I find it fascinating that we’ve found a bunch of good employees here in Orlando just by chatting up some of the locals at the neighborhood taco truck,” she says. “And we’ve had solid prospecting with hosting hiring events in partnership with a local career center, or even the Goodwill center.”
In Pittsburgh, Fifth Season’s Webb leans on a burgeoning local tech hub scene that has organically bubbled up in the city’s Oakland neighborhood near Pitt University and Carnegie Mellon University. They are also working on getting to know the neighbors, which the leadership team hopes will help the group hire more local prospects based on referrals.
“We’re working on these walk-up events for the people that live here in town, so they can learn about the facility, they can come in and ask us all the questions that they have and see what we’re doing here, and also get some fresh, nutritious locally grown food to take home with them as well,” he shares.
How COVID changed the game
AeroFarms proactively kick-started the touchy process of determining which employees were indeed “essential” to the operation, and thus would remain on site through much of the pandemic, and those who could conceivably function and provide support remotely.
Then, the real heavy lifting came into play.
“I feel like we were way ahead of the game in setting up daily temperature taking stations before it was mandated by the state. I’d say overall we did a really good job [dealing with COVID],” Feinstein says. “Now we bring in someone to COVID test our employees on site every two weeks, and the employees really seem to appreciate that.”
Instead of panicking and barking up every tree in search of a magic solution to deal with COVID, Feinstein says the group’s cool headedness has paid dividends.
“We kept a cool and calm mindset, and we just looked around and we kind of realized that all of the resources and knowledge that we have around us in this diverse organization, that we could lean on that and we could make this work,” she says.
The pandemic itself added to the preliminary hiring qualifications that Kalera looks for in a candidate. Sure, passing a pre-employment drug screen and background check are still important boxes to check, but now just as crucial is making sure a prospective employee will fit in with the ethos of the greater organization.
“I think COVID has been really unique in that it’s become this all-encompassing, moral, political, ethical and health issue, and for us it’s just as important that anyone we hire finds alignment with how our organization views and responds to COVID as those other pre-employment screening activities,” Gasiorowski says. “And keep in mind you’ll likely have employees with opinions about COVID that fall on both sides of the aisle.”
At Fifth Season, Webb points to the strong culture the group put in place from the start as the catalyst in holding everything together during a chaotic time.
“My biggest tip is to establish your culture first. That is just incredibly important because it influences how people work together, as well as how innovative whatever they’ve been hired to produce will turn out,” he says. “Start from day one with a leadership outlook, get that great culture in place with a great team and great leaders, and then it just becomes as simple as finding the right talent pipeline and building that up.”
Expansion comes two-fold at Great Lakes Growers
Features - operation update
One of Ohio’s earliest adopters of CEA leafy green and herb production added on to the greenhouse, and aggressively upscaled its product offerings, in 2020.
What was born a decade ago from an experimental crop of butter lettuce in 300 square feet of homemade poly greenhouse today has evolved into 3 acres of sleek and efficient production under glass.
Great Lakes Growers in Burton, Ohio, efficiently and perpetually plants, harvests and ships 12 different leafy green product mixes, as well as 14 fresh cut herb offerings, in a sleek, modern, Dutch-style double gutter connected greenhouse about 40 miles south of the Cleveland-Akron/Canton metropolitan area.
Head grower and founder John Bonner describes the operation as “semi-automated” when it comes to its level of technology adoption.
“We’ll always be that way, we’re not going to go to full automation like you hear about with a lot of the vertical farms that are coming online more and more,” he says. “We like to be able to touch and see our plants up close.”
Expanding amid the pandemic
In 2020, GLG added on 10,000 square feet of climate-controlled packing space, as well 60,000 square feet of teched out row space for crop production. We are talking all the horticultural bells and whistles, with the latest in lighting (LED toplights for supplemental), automation (climate controllers), HVAC and nutrient film technology (NFT) irrigation and dosing, as well as sliding benches.
Previously, GLG added on 80,000 square feet of canopy space back in 2018, doubling its production capacity just in time for the local microgreens trend to take hold amongst consumers.
Over the last few years, the facility add-ons have backed impressive growth and continued diversification of GLG’s product offerings, according to Bonner. Today, the grower ships 25 unique retail items to regional grocery players like Heinen's and Giant Eagle, GLG also serves an extensive food service line for local restaurants and chefs that Bonner admits right off the bat has “taken a bit of a hit during the quarantine, although it’s opening up more now, thankfully.”
“We feel like we’ve finally uncovered most of the skeletons in the closet when it comes to growing these crops,” Bonner says. “We’ve faced and overcome a lot of the unique challenges to indoor growing – pests, diseases, climate issues, you name it – and now we’re pretty comfortable with where we are.”
Comfort for Bonner equates to pressing pause in the short-term on more facility expansions (the group has room at its current location to scale up to 5 acres under glass eventually) and focusing more on building out relevant and consumer attention grabbing product lines. Even with the temporary hit to its food service business, GLG is still enjoying very robust demand at retail.
“We’re focusing on organically growing these product lines, getting out into some of the surrounding Midwest states like Michigan, western New York, Pennsylvania and Virginia, as well as other regions with our partners,” Bonner says, noting the various intricacies that must be managed when shipping a perishable product, as well as the rising expense of trucking out product.
Photos courtesy of Tim Ward
Top: GLG's latest expansion project features LED toplighting fixtures and climate controllers. Bottom: GLG founder John Bonner
Enabling expansion
Two somewhat recent developments in the CEA industry have made GLG’s commitment to expansion easier to execute, according to Bonner: the improved efficiency and lowered cost of new LED lighting technologies, and a greater commitment from seed breeders to hunt out phenotypes that work best for indoor production.
Bonner started out with HPS lights, but after establishing a trial space in the greenhouses’ experimental range with LED toplighting fixtures from Philips, he was quickly convinced.
“We started seeing a 35% boost in production capacity, and just from a plant quality standpoint, the LEDs have really flattened out our production lines in the winter, because with the HPS lights we were seeing a major yield hit in the winter months,” Bonner says.. He also notes that the LEDs have even made the operation’s finished crops taste better.
Genetics-wise, he is excited to see the seed breeding companies focus more heavily on breeding plants with characteristics that are ideal for his type of growing style. Just a few years ago, that type of genetic diversity simply did not exist yet, and all of GLG’s lettuce crops are still grown from seed in seed trays, while vegetative cuttings are used for much of the CEA's fresh herb production.
“The focus from the seed companies to develop genetics for this market has really come full circle. Now, they’re breeding lines specifically for us,” Bonner explains. “They’re releasing new romaine cultivars with really vibrant colors, and new lettuce varieties with improved disease tolerance. It really does make this job a little bit easier.”
Final takeaway
It bares mentioning that what Bonner and Co. at GLG are doing should not be considered, in any sense of the word, easy. Unlike his neighboring row crop farmers in Ohio’s ag-focused Geauga County, there are no crop insurance policies to cover indoor crop losses. And generally speaking, growing hydroponically at such a scale, is more difficult than growing in soil, since issues that arise in a hydroponic system will normally progress much faster than in container production.
Mistakes are bound to happen. Learning from those mistakes, and not repeating them, are steps one and two to carving out a sustainable standing in the CEA produce world, Bonner believes.
“There is no playbook out there on how to do this successfully,” he says. “I’ve made more mistakes than I care to admit, and no matter what you read or research, every situation is different. Are you a vertical farm? Are you low tech, or high tech and automated? Are you shipping to the East Coast, where retail prices are higher and transportation costs are a bit lower? Or are you sending your product around the Midwest, where it is a bit more spread out and shipping costs are more expensive? There are a lot of dynamics at play there.”
Gotham Greens’ new era
Features - Cover Story
Ten-plus years after its founding, the urban agriculture company has plans in motion for what's next.
Gotham Greens’ expansion began almost as soon as the company started.
“For the first few years, we were focused on proving our business model, making sure it was financially sustainable,” says CEO and co-founder Viraj Puri. “And then we expanded to Chicago after about five years in business and that was successful.”
After three years of planning by Puri, co-founder and CFO Eric Haley and chief greenhouse officer Jenn Frymark, Gotham Greens’ original facility opened in 2011 in Brooklyn, New York. Next up was another Brooklyn farm, which opened in 2013, followed by two in 2015: one in Queens and one in Chicago — the company’s first footprint outside of New York. Twenty nineteen then marked the next step in Gotham Green’s evolution. That year, the company opened two more greenhouses: one in Edgemere, Maryland, and one in Providence, Rhode Island. Then, in May 2020, it opened a 30,000-square-foot facility in Colorado. Each new facility — and those still to come — are part of the company’s plan to be a major player in a localized and decentralized food system.
By the end of 2020, Gotham Greens had secured more funding to fuel future expansion amid a year where retail sales increased dramatically. In December, the company announced it had raised $87 million in a Series D funding round, pushing its total in capital raised to $130 million. According to Viraj, the money will be primarily used for expansion, both in terms of building new facilities and expanding current ones as the company heads into its new era.
“We’re going to be expanding to more geographies and expand our distribution via retail, via food service and getting our products into meal kits,” Puri says. “The other thing is to increase our operational capacity. All of our greenhouses were designed with the ability to increase size and expand the square footage to meet increasing demand. We’re going to be doing that, too.”
Why now for new investment?
Gotham Greens isn’t the only company to obtain new investment in the past few months. Recently, Kentucky-based AppHarvest went public with an IPO, raising $475 million in gross proceeds. Massachusetts-based Little Leaf Farms raised $90 million in private funding with an eye on expansion throughout the East Coast. Oishii, a New York-based, Japanese-style vertical farm producing exotic varieties of strawberries, announced Series A funding March.
The influx of cash into the industry — predicted to grow exponentially as more product shifts to greenhouses and vertical farming operations, according to Puri — isn’t likely to slow down any time soon. Puri notes that the market for CEA grown products in the U.S. and Canada is currently valued at $100 billion with only a small percentage of crop output coming from greenhouses and vertical farms.
“We’ve been advocates for growing this industry for a long time and I’ve been very excited to see that there’s a lot more retailer interest, consumer interest and investor interest in the space,” he says. “And I continue to see a lot of growth opportunity for this industry.”
In Gotham’s case specifically, Puri said the company weighed a public offering, but elected to not pursue that route now in favor of another round of funding. Way back in 2019, he says the company was beginning to explore other funding options and continued to do so into 2020 before the COVID-19 pandemic hit. That, he says, caused their food service business to slow to a crawl, but with the retail side more than picking up the slack. Gotham, like other companies in the ag space, were able to grow by solving food supply issues for leafy greens and herbs stemming from field producers primarily based on the West Coast unable to fulfill orders as expected.
“This accelerated expansion has been a work in progress for some time,” he says. “It wasn’t just ‘Hey, we arrived in 2020, the pandemic happened and then go raise a bunch of money and that.’ This was already happening. I think what the pandemic has sort of done is that it’s accelerated our expansion a little bit further because we’ve really been able to serve our value proposition to so many of our customers from a regional supply chain standpoint.”
Puri expects that trend to continue with more and more retailers becoming more comfortable with greenhouse suppliers and embracing food that can hit shelves within a few days of a harvest. Back around 2011, it was a lot of cold calling companies and pitching them on the concept for Gotham Green’s sales professionals. Now, Gotham Greens is on the shelves of major retailers like Target and Whole Foods.
“I think we paved the way for the entire industry,” he says. “I’m not trying to brag or say that with any hubris, but it was much more difficult back then for a retailer to bring in locally grown, greenhouse grown produce. Now, it’s seemingly every week or every month that a new company is doing it. It’s become much more mainstream — we don’t need to tell the story because it’s been proven.”
From left to right: CFO Eric Haley, Chief Greenhouse Officer Jenn Frymark and CEO Viraj Puri, Gotham Greens' three co-founders
Communication is king
The core of what Gotham does — local food production — hasn’t changed, but the form it takes on has shifted slightly.
“The technology has moved a lot,” Frymark, the group’s chief greenhouse officer, says. “It wasn’t proven at scale yet. We were the first movers in this space and for the type of model we were going at.” The first Gotham greenhouse, she says, was really a proof of concept. The Gotham setup has changed over time too with the first four farms built on rooftops.
“That hyperlocal, urban location requires a certain type of technology for how you’re going to attach it to the building, as well as how you’re going to handle structural load concerns,” Frymark says.
Since then, as Gotham has open bigger facilities, they have moved the concept more towards being built on the ground. That, in turn, means there is in theory more places to build. They also use natural sunlight for production vs. supplemental lighting, which limited the number of places in New York City where a greenhouse could be feasibly built.
“We’re so focused on using the sun — it’s our most renewable resource and plant growth is the best under solar radiation,” Frymark says. “Land for a greenhouse with access to sun is really hard to find in New York City, so that was why we looked elsewhere.”
As the grower has become more decentralized, Frymark says the operation has continued to embrace technology more and more. To help on-site growers at each facility, data is collected at each facility and analyzed in detail to learn as much as possible from it. Even if it is not done directly by the different growers, a grower in Maryland can learn from what a grower in Denver is doing, and vice versa. At the head grower level, there are virtual team meetings each week to discuss what is happening at each facility and what the company can learn from each development. Frymark says that this is immensely helpful to Gotham Greens, as it helps growers continuously improve and was baked into the company’s model from the beginning.
“Greenhouse growing is half art and half science,” Frymark says. “They can walk the facility and see what’s happening with the plant’s physiology and handle the environment to get the desired yield and quality. But that’s a lot for the human mind to handle. I think giving people tools — the more you can build them out for people and help our talent, it makes us even better growers. I don’t want a culture where our greenhouses are competing against each other.”
This approach has been particularly useful during the on-going COVID-19 pandemic, when the world is changing rapidly, and businesses need to react quickly.
“There’s no sort of guidebook for how to deal with this,” Puri says. “So every couple of days there’s a new situation or a new circumstance to be aware of. You’re building the plane as you’re flying it so to speak, and it’s been mentally and physically exhausting for the past [several] months to have to make new decisions on things based on new information and new circumstances and changing guidance from government agencies and regulatory agencies and public health officials.”
“Being a greenhouse grower is a really hard job,” Frymark says.
After originally building greenhouses on rooftops, Gotham Greens began building greenhouses on solid ground and then looked beyond its original New York City hub.Dressings and other prepared goods are a small, but still growing, part of Gotham’s overall output.
The next steps
In the last few years, Gotham has added to its product portfolio on the edges. In 2017, for instance, the company started selling so-called “ugly greens” that had blemishes or other defects and, while edible, not up cosmetic standards. It has also added chimichurri, pesto and different salad dressing made from its own products as a compliment to the main line of lettuces.
The produce, though, remains — in Puri’s words — ‘the star of the show.’ In the coming years, growth for the company’s business plan will still be about producing more leafy greens and herbs than trying out new products as greenhouse-grown products take a larger market share vs. field grown product.
That said, Puri says that Gotham Greens is looking outside of its current focus for potential future expansions. Nothing is imminent, but ideas have been floated around.
“A lot of people are already growing tomatoes and peppers, so we may not get into that. But certainty strawberries are of interest,” he says. “I think there’s a lot of room to grow even just in terms of what crops we’re growing.”
“It’s hard to say exactly what that’ll look like,” Frymark says. “But I think we’ll have tremendous success with our greenhouses and new products, and eventually bring even more new stuff to the market. We are really focused on leafy greens and herbs right now, but I think we have to be flexible and opportunistic and be open to considering other offerings.”
Gotham Greens' growers all communicate in regular meetings to keep every location on the same page.
And, as expected, Gotham Greens is building another greenhouse — this time in Solano Valley, California, near the campus of UC Davis and in the state where one-third of the lettuce grown in the U.S. is produced. Announced on March 2, Gotham is building out a 10-acre facility that is expected to open later this year and will greatly increase the company’s output. It's the first phase of the California build.
Additionally, it entered a research partnership with the University of California, Davis. As part of the agreement, Gotham will work with UC Davis — which is building its own CEA consortium — to further research all parts of the indoor and urban agriculture industries. What exactly will come from this new venture is still to-be-determined — and it may be years before its full impact is understand — but it fits within what Gotham has done from the beginning: build.
“It’s an approach that combines going deeper in the existing markets with going broader to new markets,” Puri says. “The reason for going broader to new markets is that the business model was successful in New York because we felt like retailers were having to rely on a supply chain that was so far away.”
“Our thesis was that people in the Midwest are facing the same issue,” he continues. “People in New England are facing the same issue. Retailers in the Mid-Atlantic are facing the same issue. So, why not try to export the business model to other regions? And who better to do it than us because we have the experience doing it?”
Choosing the right hydroponic system
Departments - Hydroponic Production Primer
For growers considering CEA, there are a variety of system options to choose from.
Vine crops like tomatoes are best grown via slab culture and Dutch buckets due to their larger size.
Photo courtesy: chris topher J. currey
Producing food crops in greenhouse and controlled environments is an increasingly popular idea. Whether the goal is to offer fruits and vegetables when field production is not possible, have predictable yields, or increased control over factors such as food safety and/or produce quality, controlled-environment agriculture provides opportunities. In these environments, hydroponic systems are an essential part of production. This article will provide an overview of the most widely used hydroponic systems in CEA.
Systems for leafy crops
Leafy crops, such as lettuce, culinary herbs and other leafy greens are characterized by a relatively short crop time, small size and high planting density. The most widely used and most recognizable system for growing leafy crops hydroponically indoors is the nutrient-film technique system (NFT) system. The main feature of NFT systems are the channels plants are placed into and subsequently grow in. Available in a variety of dimensions, channels typically measure approximately 4 inches wide and 2 inches deep and 8 or more feet long.
Seedlings grown in rockwool, phenolic foam, or other stabilized substrate are placed into holes between 1 and 2 inches which are cut either out of lids that affix to channels for two-piece models or simply on the top of the channel for one-piece models. The channels are typically placed approximately waist-high, which facilitates comfortable planting, plant maintenance and harvest. Channels are on a 1% to 3% slope, which allows the nutrient solution to flow from the top to the bottom of the channel, bathing roots in a thin “film” of solution at a rate of 1 to 2 liters of nutrient solution per channel per minute.
These NFT systems are popular for a variety of reasons, including their comfortable working height as well as the naturally high oxygen concentrations in the nutrient resulting from solution movement. However, one of the challenges growers often face is when the pump providing nutrient solution goes down or clogs during irrigation plants don’t have long before damage occurs.
The other popular system used for leafy crops is one with several names: deep-water culture (DWC), deep-flow technique (DFT), raceway or raft culture. Regardless of the name, the idea and system are the same. Raceways are constructed out of different materials from poured concrete, metal frames, polystyrene foam and rubber liners, and sometimes even cinderblocks and plastic. In these pools, rafts float in a nutrient solution that is 4 to12 inches deep. As “raceway” indicates, the rafts are planted on one end of the pond and harvested at the other. As rafts are harvested, they move forward towards the harvesting side. This design is efficient for labor, as planting and harvesting are concentrated at specific areas. When using DWC systems, the nutrient solution must be aerated or oxygenated to maintain sufficient oxygen concentrations for plants, as these systems do not provide the natural aeration that NFT does.
Leafy green and herbs are best suited for NFT or DFT systems.
Systems for vining crops
Compared to leafy crops, vine crops including tomato, cucumber and pepper are much larger in size, with lower planting densities and longer crop cycles. While those systems used for leafy green production are not well-suited for vine crop production, there are two systems that are very popular for vine crops: slab culture and Dutch buckets.
Slab refers to plastic bags containing rockwool or coconut coir, with the most popular sizes measuring approximately 36 to 39 inches long, 6 to 8 inches wide, and 3 to 4 inches tall. In order to modify the water holding capacity, air space, and other physical properties of the substrate, rockwool fibers are packed at different densities and fiber orientation can be rearranged, whereas different blends of crushed and shredded coir are used to vary physical properties.
These slabs are often placed on hanging gutters or in troughs on the floor to facilitate drainage of excess nutrient solution. Before plants are transplanted into the slabs, they must be “prepared.” Drip stakes are placed into the rockwool or coconut slabs, and nutrient solution is provided until the bags are full. Be sure to not cut any slits in the slabs prior to filling with nutrient solution, as it would cause them to drain immediately.
The slabs can be left saturated for approximately 24 hours. For rockwool, this period allows the pH of the substrate to adjust to that of the nutrient solution, which is initially higher than desired for producing greenhouse plants. For coconut coir slabs, this preparation period not only serves to leach excess salts from the coir, but also to decompress the slabs from the compressed form they are shipped and sold in. Dutch, or “bato,” buckets, are another system commonly used for vining crops. These buckets are filled with a loose substrate, typically either coarse perlite or lightweight expanded clay aggregate (LECA). In the bottom of each container is an auto-siphoning elbow that helps drain excess nutrient solution out of the container to prevent overly saturated substrate. To prevent the siphoning elbow from getting clogged with perlite, either cover it with a small piece of screen, or put a few handfuls of LECA around the elbow to act as a filter. Since the area of exposed substrate is greater in a Dutch bucket than in slabs, covers can be placed over the substrate to minimize algae growth and development.
Irrigation in both system is similar, with a nutrient solution is delivered to plants via drip irrigation.
The take-home message
The hydroponics systems discussed here are the four most popular hydroponic systems. However, hydroponic systems encompass a wide spectrum of different technologies and systems, and there are others not mentioned here, as well as deviations from what is described in this article. Regardless, the systems described in this article are going to be a great place to start for those interested in growing leafy greens and herbs or vining crops.
Christopher (ccurrey@iastate.edu) is an associate professor in the Department of Horticulture at Iowa State University.