by | Sep 13, 2021 | Ask The Experts

Controlled Environment Agriculture

Introduction

With climate volatility becoming increasingly unpredictable and burdensome on farmers around the world, the rapid growth of a long-standing industry has come to the forefront of mainstream media as an economically viable and sustainable way humans can continue to feed a growing population. Although the term Controlled Environment Agriculture – commonly referred to as CEA – is relatively new, farmers have been cultivating a variety of crops in greenhouses since as early as the 1450’s . Flash forward to 2021 where the Controlled Environment Agriculture (CEA) market is projected to grow from USD 74,499.7 million in 2020 to an estimated USD 172,164.64 million in 2025, registering a compound annual growth rate – CAGR of 18.7% between 2020 and 2025. With CEA operations located all over the world, this article will break down some of the commercially viable designs, methodologies, outputs and major differentiators between operations.

CEA Greenhouse Hydroponics

The term “greenhouse hydroponics” identifies this type of operation by its growing environment (greenhouse) and its growing technology (hydroponics). When it comes to greenhouse technology, there are a wide variety of designs, construction materials and environmental management technologies available to home, hobby and commercial farmers. The most common materials used as greenhouse cover (or glazing) are glass, polycarbonate (dual or triple wall), acrylic and polyethylene (single sheet or dual-inflated). Greenhouse materials have a direct impact on operations within the greenhouse due to their reactions to: light penetration, building insulation, ventilation design, wind/snow load and lifespan. When considering a new commercial greenhouse, budget, climate, and cultivar selection are three of the major factors that inevitably determine the most effective greenhouse for an individual or business.

CEA Greenhouse Example

Now that we have discussed the “shell” of the operation, what equipment goes inside is up to the farmer and their desired crop (cultivar) selection. The global greenhouse industry has evolved from crops planted in soil to completely soilless designs that maximize water conservation and enable precision fertigation in zones tailored to specific crops. A majority of greenhouse hydroponic operations are cultivating crops such as: indeterminate tomatoes, peppers, cucumbers, eggplants and strawberries. These crops are commonly grown in bato/ dutch buckets or substrate logs where a drip line and emitter distributes constant or intermittent fertigation to the plants directly at the root zone. Other growing techniques and technologies commonly used in greenhouse operations include: ebb and flow (flood and drain) tables, deep water culture (DWC), nutrient film technique (NFT), aeroponics and vertical towers. These growing techniques are frequently utilized for smaller and fixed-growth plants like leafy greens, herbs and flowers. Similar to Greenhouse selection, a farmer / business owner will need to determine the appropriate grow technology for their operation as it relates to their cultivar selection, operational scale and budget.

Some notable commercial greenhouse hydroponics operations include: Nature Fresh Farms (North America), Ceres (USA), Lufa Farms (Canada), Gotham Greens (USA) and Bright Farms (USA). Each of these operations have similarities and differences in both their greenhouse designs and growing equipment selection in relation to their core products, geographic location, operational scale and budget.

CEA Aquaponics

The term aquaponics brings together aquaculture and hydroponics, highlighting a biological symbiosis between fish waste and plant nutrients that enables the cultivation of both products under one roof. Greenhouse aquaponics operations are located all around the world, with a large market concentration in North America (of 42-45%). Industry leaders such as: Rebecca Nelson / John Pade (USA), Murray Hallam (Australia) and Nick Savidov (Canada) have helped evolve commercially viable approaches to aquaponics, providing training, equipment, designs and applied research insights to both established and aspiring growers.

When it comes to outputs from aquaponics farms, the most common aquatic species being raised include: Tilapia, Catfish, Trout, Blue Gill, Striped Bass, Cod, Barramundi and Koi (4). These species are most common among farms due to their market pricing, environmental needs and ease of management. Environmental considerations when selecting a fish species for aquaponics include: water temperature, stocking density, dissolved oxygen, flow rate, pH and feed inputs. Aquaponics systems can be “coupled” (aquaculture tanks constantly recirculate through the hydroponic growing area) or “de-coupled” (aquaculture and hydroponics operate as two, separate, parallel ‘loops’). Depending on the design, a farmer can increase diversity of both crops and aquatic species in their operation by catering to the needs of each ‘side’ of the aquaponics operation.

Nelson-Pade commercial aquaponic systems

The most common design used in commercial aquaponics operations is Deep Water Culture (DWC) or Raft Culture, where plants are grown on floating rafts atop 12 to 18 inches of water. The plants sit within holes in the floating rafts and their roots are submerged in the water; nutrients are taken up by the plant roots as water constantly moves throughout the growing beds and recirculates back to the aquaculture zone. This design has some limitations to the cultivation of larger plants, but has proven very effective for greens, herbs, small vegetables and edible flowers. Water filtration is arguably the largest limiting factor to expanding the hydroponics design of an aquaponics farm; the result of small organic particulates that circulate throughout the system and eventually form biofilm on the pipes and fittings. Operations that invest in proper filtration equipment are able to utilize other cultivation equipment (Nutrient Film, Drip, Grow Tower) without worrying about plumbing issues down the road.

Some notable aquaponics businesses are: Bigh Farm (Belgium), Superior Fresh (USA), Nelson & Pade (USA)

CEA Indoor Hydroponics

Indoor and vertical hydroponic farms have been making headline news over the past six years as a novel and sustainable means of producing food on non-arable land, within cities, underneath cities and in remote locations. Growing crops indoors maximizes the operator’s ability to control and maintain specific environmental conditions for plants with the goal of maximizing yield and minimizing operational costs. Vertical farms are designed using a horizontal, multi-layer approach or a vertical plane approach, where plants are cultivated in layers on racking or within vertical growing equipment. Some of the major indoor growing equipment includes: LED grow lights, HVAC / dehumidification equipment, circulatory fans, fertigation / dosing equipment and plant substrate.

vertical farm

With indoor farms located around the world, the use of growing equipment is diverse and constantly evolving across the industry as automation becomes an important driver of long-term profitability. Indoor farms primarily produce microgreens, leafy greens, culinary herbs, edible flowers and other novelty crops that are compact and have a short life-cycle. Operations such as AeroFarms (USA) utilize a multi-tiered, aeroponics design to cultivate quick-turn microgreens for their market, while Plenty (USA) cultivates crops on a vertical plane within vertical hydroponic towers. There are tradeoffs with every design and equipment selection when it comes to an indoor farm so it is important to have a comprehensive plan and market strategy before making any major decisions. Some of the key considerations when designing and selecting farming equipment for an indoor farm include: desired crops and production strategy, spatial dimensions and workflow, load of equipment and water on floor/pad, movement of people to safely access plants on upper tiers, seeding and harvesting procedures, cleaning and sanitization procedures, and water + energy access and consumption.

Some of the notable indoor hydroponics operations include: Bowery Farming (USA), 80 Acres (USA), Jungle Farms (France)

CEA Container Farming

Container farming involves the use of modular containers as the primary, sealed shell of the growing environment. This style of indoor farming has been around for over a decade and offers a low-cost, flexible solution for startups and hobby growers around the world. Both exterior and interior designs of container farms range in sophistication and scale depending on the technology partner, growers needs and budget of a project. There are hydroponic, aquaponic, mushroom and insect container farms operating at all scales of business and with varying degrees of automation and equipment outfitting. The modularity of these systems has enabled the use of container farms in remote, and indigenous communities to help improve access to affordable fresh food and encourage entrepreneurship among local populations.

CubicFarms container farming CEA

An effective CEA container farm must have appropriate insulation and HVAC / humidity control to manage the temperature variation between the outdoor and indoor environment. In addition to climate control, containers must be outfitted with proper equipment for all aspects of the operation, including health and safety considerations, workflow, equipment sanitation, waste disposal and even bathrooms for staff. The majority of container farms are designed for workers to be within the space performing tasks in one or multiple zones; however, companies like Cubic Farm Systems are utilizing the entire space of a container for fully automated crop cultivation. Overall, container farms hold great promise for the future of food production in both remote and tight urban spaces due to their modular and turn-key features. The major limiting aspects of container farming surround staffing and workplace considerations; containers are quite tight spaces to work in once filled with equipment – restricting accessibility. They are also designed as sealed boxes for the shipment of goods, meaning that neither ventilation or windows come standard with anything that is not prefabricated.

Some of the notable companies working exclusively as container farm manufacturers are: Freight Farms (USA), Cubic Farms (Canada), Farmbox Foods (USA), and The Growcer (Canada).