Photo: Adobestock

As technologies such as robotics, artificial intelligence and the Internet of Things (IoT) develop at a dizzying pace, the World Economic Forum claims the world is entering a “fourth industrial revolution.” Klaus Schwab, founder and executive chairman of the World Economic Forum, writes on the nonprofit’s site that this revolution “is characterized by a fusion of technologies that is blurring the lines between the physical, digital, and biological spheres.”

Produce professionals at the forefront of greenhouse production and vertical farming technology realize this, and they seize the opportunity to utilize technological developments to garner investment, improve crop yields and maximize profits. Companies in the produce space offer technologies such as cameras and monitors that notify growers of pest and disease issues; robotic systems that sort, cut and label fruits and vegetables; and hydroponic channels that maximize space efficiency.

In this section, read about several innovative technologies and companies that are influencing the way the produce industry operates, beginning with a profile of indoor farm Plenty here. Next, read about vertical farms in the third part of the Urban Agriculture Series on here. Then read about how columnist Leslie F. Halleck uses technology in her life here. Additionally, you will find stories on automation in hydroponic systems (here), sensor technology (here), a smartphone app (here), produce labeling (here) and robotics (here).

The advancement over the past several decades of technological tools for controlled environment agriculture (CEA) has been nothing short of incredible. Techniques such as hydroponic growing have been around for much longer than that, but have become even more efficient and productive in recent years. In this issue, we’re honing in on several of these technological advancements, including vertical farms that allow growers to produce anywhere, automation that reduces labor needs, sensors that can tell you when a plant has pest, disease, water or nutrition issues, and much more.

Technology has also opened up the lines of communication with consumers. Growers can now reach potential customers directly via social media, email newsletters and their websites. However, growers must use these tools wisely. In contrast to 10 or 20 years ago, news of anything your company does or says — good or bad — can spread quickly online. For example, I recently received a newsletter from a produce company with a photo of a crop that didn’t look quite right. I don’t claim to be a plant specialist, but I do know a few, so I sent the newsletter off to a colleague. He confirmed that the pictured crop was suffering from either a nutritional disorder or perhaps a spider mite infestation; it was difficult to tell from the low-res photo alone, but there was certainly something wrong with it.

Now, as produce growing gurus, I’m sure you’re wondering, “How could they possibly allow a photo of an unhealthy plant to go out in a digital marketing campaign?” I thought about it, and surmised that the marketing person who created the email newsletter likely wasn’t a plant expert, either. As you continue to advance the technology within your greenhouse, be sure to also pay close attention to the technology that connects you with your customers outside the greenhouse, too.

Although these technologies can bring with them their own set of challenges, it’s an exciting time to be in the produce industry. Technological advancements have continued to develop and shift the way we think about what it means to be locally and sustainably grown, and how we connect with consumers. What new technology have you incorporated into your operation to make it more efficient and productive? What tools have helped you to communicate with consumers? What technology do you hope will become available in the future? Drop me a line at kvarga@gie.net and weigh in.

kvarga@gie.net | (216) 393-0290

Twitter: @Karen_GIE

When Plenty was founded in 2014 by CEO Matt Barnard and chief science officer Nate Storey, it was based on a core idea: Field agriculture was too unpredictable, and controlled environment, high-tech growing was a better way to supply quality food to a world that will need more of it in the years to come.

“There will be an increasing need, both for food in the world, as well as variability around the food supply,” Storey says. “We scaled up over the years. And as we’ve done that, the vision has of course not necessarily changed, but deepened, I would say, to include the idea that people don’t just need access to food, period, they need access to really good food.”

Plenty’s first farm — Storey calls it a container farm — was on the campus of a large technology company in San Francisco, and over time has grown to 100,000 square foot facilities. The business also evolved from its early days, when Barnard was using much of his own money to fund it and Storey splitting his time between his own startup — Bright Agrotech, based out of his previous home of Laramie, Wyoming — and Plenty, to receiving multimillion-dollar investments from investment groups that include Amazon founder Jeff Bezos and Masayoshi Son, the richest person in Japan with an estimated net worth of $23 billon, according to Forbes.

It was at this California-based tech company the heart of America’s currently booming tech industry, that Plenty found what worked and what didn’t in its system.

“[Starting there] basically give us time to learn, to understand the problems really clearly, and understand how indoor production can possibly solve the [problems] that we were identifying in the field,” Storey says.

How the system works

Plenty, which is currently based in San Francisco, is unlike most other vertical or container farms that grow plants on horizontally stacked shelves. Instead, Plenty uses tall poles to house the plants, which then grow out horizontally. Each pole is a few inches away from the next one, allowing crops to grow densely to the point where they essentially form a wall. The setup also allows excess heat from the lights to rise into the vented ceiling and excess water to drip down to the bottom of the plant towers and into a recyclable indoor stream, with space in front of the walls for workers to check on the plants’ health during the growing process. All of the water is then filtered and recycled back into the farm. As for harvesting, robots can handle at least part of it, but Plenty sees expertly trained human labor as a key part of its recipe.

Plenty, according to Storey, has benefited, and should continue to benefit, from the rapid evolution of growing technology.

“All of these things are dropping, precipitously, and it opens the doors for us to start leveraging that information, and those technologies, in ways that both drive costs out of our model, and make it feasible,” Storey says. “It’s true. A lot of folks who looked at this five, six years ago and said that that is not possible, they were right. It wasn’t possible that day. [It] wasn’t possible at that time, because the technology hadn’t evolved. No one — well, a few people predicted it — but very few people predicted the ways in which the economics of this business would change. And how fast it would change.”

What’s next?

The decreasing cost of technology also helps Plenty work towards another one of its goals: making its products more affordable.

“If our goal is just to produce a premium product we would be a much smaller business,” Storey says. “We would have to be content with being a smaller business. Our goal is, of course, to build a business that is global.”

A story published in Bloomberg indicated that Plenty has global ambitions and, with Son’s backing, has the financial means to expand. According to Bloomberg, Barnard has met with 15 governments on four different continents.

“It’s never going to replace the field by any means, but it’s going to become a really important part of our food production system,” Storey says. “[Our model] is stable, and it allows us to produce some of these high value horticultural products, closer and closer to people. And we just think that’s an important part of the experience, in a lot of different ways. In the next five years, 10 years, 15 years, I think we’re going to see our farms spring up all over the world. I think that people are going to be surprised at the diversity of crops that end up coming out of our farms.”

The diversity of crops is key to Plenty’s plans, which is why the company has a research and development division dedicated to developing genetics for its system because some seeds bred for field are not fit for any indoor growing system, much less one as advanced as Plenty’s. As that part of the business continues to develop, it allows the business to expand.

“We’re working both angles,” Storey says. “It’s important to us that we’re not just finding the appropriate environment for the crop. We want to grow, but we’re finding the appropriate crop and the appropriate environment. We’re kind of having this melding of both sides of the equation, and getting to the best possible place, as fast as possible.”

This article series is from the Resource Management in Commercial Greenhouse Production Multistate Research Project.

Indoor vertical farming systems or plant factories use controlled environment agriculture (CEA) technologies to grow high-value horticultural crops year-round in pre-existing urban warehouses or shipping containers. The internal building of warehouses is most often converted into a growing environment with the goal of achieving higher biomass production compared to outdoor or greenhouse production. The essential components of a vertical farm include multi-layer production shelves, hydroponic, aeroponic, or aquaponic growing systems and sole-source electrical lighting consisting primarily of high-intensity light-emitting diodes (LEDs) (Figs. 1A and B) or fluorescent lamps. However, detailed engineering design fundamentals for heating, ventilation, and air conditioning (HVAC) systems, uniformity of the environment, optimal delivery of carbon dioxide (CO₂), shelf spacing, smart lighting and shelf designs, and interaction of crops and surrounding climate in terms of heat and mass-transfer processes are often overlooked in such retrofits. Optimizing the use of resources such as energy, water, nutrients and CO2 is essential for the long-term viability of vertical farm systems, where energy intensive lighting and HVAC systems can account for close to one third of the overall operational costs. The operational costs and resource use efficiency (defined as the ratio of resource fixed by the produce to resource used by the plant; Kozai, 2013) of multi-tier-based vertical farm systems can be improved by appropriate production system design modifications for key technologies and control strategies while considering the crop-specific minimum environmental requirements such as light intensity and quality, air temperature, velocity and flow pattern, CO₂ and uniformity of these variables.

Many millennial vertical farmers are data-driven and rely on recent technology developments in sensors, environmental monitoring and control, and information and communication technologies. Integrated monitoring and control of the crop and production system and analysis on average account for about 9 percent of a farm workforce’s weekly labor hours (Agrilyst, 2017). It is expected that these technologies will further advance with integration of the diverse set of analytics platforms made available for growers and system operators empowering them to improve production quality and overall resource use efficiency. The technologies that vertical farming operations are most excited about include automation, HVAC, LED lighting systems, smart sensors and data analytics.

Challenges in vertical farming

Several economic challenges make vertical farming a difficult sector to enter and be profitable including both high start-up costs (particularly lighting, vertical growing systems, and sufficient HVAC capacity) and high operating costs (especially energy and labor). In greenhouses, labor is typically the largest production cost followed by energy. In vertical farms, energy costs may be equal to or greater than labor. In a recent survey of CEA operations, 27 percent of vertical farms reported being profitable as compared to 67 percent of greenhouses (Agrilyst, 2017).

In 2016, an energy use simulation was conducted for lettuce production in greenhouses and vertical farms in diverse climates across the U.S. Per unit of lettuce, vertical farms in Minneapolis would require 1.4 to 2.4 times more energy than greenhouse counterparts; while in an arid climate like Phoenix, a vertical farm would require five to 10 times more energy than greenhouses (Harbick and Albright, 2016). Energy use was evenly split between lighting and HVAC systems. Another simulation-based study (Graamans et al., 2018) compared greenhouses vs. vertical farms in the Netherlands, United Arab Emirates, and Sweden in terms of resource use efficiency per unit biomass of lettuce: In all cases, purchased energy (heating plus electricity) used by greenhouses was less than plant factories. Climate made a large difference in the extent of energy savings. In a moderate climate like the Netherlands, greenhouse energy was three times less than the plant factory, while in an extreme northern climate like Sweden, greenhouses used only 15 percent less energy than plant factories. However, beyond energy, it was noted that vertical farm-based production could achieve higher productivity for all other resources (water, CO2, and land area). Currently, energy costs average $8 per square foot production space and represented 25 percent of annual production costs in large vertical farms (Agrilyst, 2017). Therefore, there is further need for research on analysis of resource use efficiencies and to develop resource-conserving environmental control strategies (Fig. 2).

Automation in vertical farming

While indoor production may lend itself to increased automation (vs. field production), the nature of vertical farming (multi-layered production) appears to make it difficult to automate. Processes that in 2-D greenhouses (moving plants to the production space, respacing, sorting, and harvesting) are more time-consuming and labor-intensive in 3-D. For example, accessing crops for maintenance, monitoring, and pulling for harvesting typically requires added labor time through use of ladders or scissors lift in vertical farming (Fig. 3). Thus, automation and robotics systems need to be integrated for such operations.

Nutrient management in vertical farms

Indoor vertical farming operations take advantage of technology and automation to improve production efficiencies. This includes optimization of the root-zone (in terms of pH, fertilizer nutrients and dissolved oxygen) to produce high-quality crops and reduce nutrient waste. However, managing nutrients in vertical farming does not have to be high-tech or complicated. In addition, common nutrient management techniques used in greenhouse hydroponic and container crop production also apply to vertical farming.

Measuring electrical conductivity (EC) and pH in the rootzone are common methods for monitoring crop fertility. EC refers to the concentration of total nutrients surrounding roots, where greater EC values indicate a greater nutrient supply. pH refers to acidity or basicity in the root zone (where pH 7 is neutral), which influences the solubility and availability of nutrients for uptake. For most crops, nutrients are adequately available at pH 5.6 to 6.4. Multiple factors interact and can influence nutrients and pH during vertical farming production. For strategies on managing these factors, check out our previous Produce Grower article, “Edible crop species differ in their pH effect in hydroponics,” at bit.ly/2CNsGUk

In addition to measuring root-zone pH and nutrient levels, growers should periodically conduct detailed nutrient analyses on both the applied nutrient solution and plant tissue using a commercial lab. This helps growers check their own in-house pH and EC measurements, and verify that they are supplying individual nutrients in the correct amounts. Tissue nutrient analyses provide information on the amount of nutrients the plants are taking up, which helps growers adjust their fertilizer program for optimal plant growth and diagnose nutritional problems. Visual inspection of plants to diagnosis nutrient and other disorders remains important in plant factories but can be difficult under sole-source LED lighting. For example, under narrow waveband red and blue light, plant surfaces appear pink or purple. Some lights have a human vision feature to turn OFF red/blue light and turn ON white (broad-spectrum) light to inspect plants, or operators use special glasses with green lenses to see plants with natural colors. Computer vision systems can help enhancing plant inspection for growth, health monitoring and environmental control purposes and as an integral part of needed automation and robotics applications.

Future prospects

Vertical farming can meet consumer demand for high-quality, nutritious, chemical-free, and locally grown horticultural crops. Due to high production costs, there should be additional benefits delivered by sole-source lighting and CO₂ enrichment (such as phytochemical, nutrient or color enhancement). Research and development to improve labor and energy-use efficiency as well as increased uniformity of the growing environment will be important to address industry viability/profitability. Further, there is an increasing demand by the vertical farm industry for an educated/experienced workforce who understand both the biology and engineering of controlled environment crop production systems. Because the industry is young, the workforce has largely come from related industries without prior experience specifically in indoor climates. Therefore, it’s critical to maintain and further grow controlled environment agriculture-based research, educational, and extension/outreach programs offered by higher education institutions to meet the industry’s demands.

References

Agrilyst. 2017. State of indoor farming. https://www.agrilyst.com/stateofindoorfarming2017

Graamans, L., E. Baeza, A. van den Dobbelsteen, I. Tsafaras, C. Stanghellini. 2018. Plant factories versus greenhouses: Comparison of resource use efficiency. Agricultural Systems, 160: 31-43.

Harbick, K. and Albright, L.D. 2016. Comparison of energy consumption: greenhouses and plant factories. Acta Hortic. 1134, 285-292.

Kozai, T. 2013. Resource use efficiency of closed plant production system with artificial light: Concept, estimation and application to plant factory. Proceedings of the Japan Academy, Series B, Physical and Biological sciences, 89: 447-461.

Ying, Z. and M. Kacira. 2017. Analysis of environmental uniformity in a plant factory using CFD analysis. Presented at GreenSys 2017-International Symposium on New Technologies for Environment Control, Energy-Saving and Crop Production in Greenhouse and Plant Factory, August 20-24, Beijing, China.

Acknowledgements

Financial support was received from the USDA National Institute of Food and Agriculture, Multistate Research Project NE-1335: Resource Management in Commercial Greenhouse Production. Murat is a professor at the University of Arizona (mkacira@email.arizona.edu), Ryan is an extension professor/specialist at the University of New Hampshire (Ryan.Dickson@unh.edu), Neil is an associate professor and extension specialist at Cornell University (neil.mattson@cornell.edu) and Roberto is an assistant professor and floriculture/controlled environment specialist at Michigan State University (rglopez@msu.edu).