To feed nine billion people in 2050, the ratio of food produced per unit arable land must be increased substantially. Greenhouses will be part of the solution. Greenhouse horticulture is a resource-efficient and environmentally friendly production system with enormous yield per unit area. Greenhouse-grown food products have consistently high nutritional value, and greenhouse operation is economically profitable.
—LEO F. M. MARCELIS AND SILKE HEMMING
In the effort to localize the food supply in the Colorado Front Range, with a goal of 25 percent food localization within the next decade, one of the most significant challenges is limited production capacity. Demand for local food far outstrips supply, forcing commercial buyers to rely on out-of-state producers (California), out-of-country sources (Mexico), or even U.S. conventional growers for access to “fresh” healthy food. Export-oriented commodity agriculture dominates the economic landscape, which is true in most regions throughout the nation.
Despite the growth of the organic food industry, which reached a reported $39 billion in 2014, there is concern that farmland is not being converted to organic production at a pace that will continue to support demand. The local food industry—now at an estimated $12 billion—has been growing more rapidly than the organic food segment, but unless local food production capacity is significantly increased, that growth rate could stall.
Several factors in the Front Range combine to significantly inhibit the growth of local food production.
• Lack of affordable land. Of the nine million acres of farm and ranch land in the region, most are committed to commodity-crop production, animal pasturing, and hay production. Conventional producers, who are supported by federal subsidies and other forms of support, see few incentives to produce food for local consumption—especially since the distribution and marketing infrastructure is limited. Meanwhile, land prices are prohibitive for many prospective farmers, as well as for established farmers who wish to expand operations.
• Short growing season. The growing season (April to September) limits food production to half of the year. Buyers do their best to adapt to seasonal availability by relying on distant producers. Meanwhile, local producers struggle to find supplemental sources of revenue during the off-season, complicating their ability to attract and retain labor.
• Increasing drought and decreasing water supply. State officials say that about half of Colorado is currently in some level of drought. Most areas of the state normally receive less than twenty inches of natural precipitation each year, so most agricultural production requires irrigation, with the majority of water supplies coming from unpredictable snow-melt runoff. Meanwhile, water demands by rapidly growing municipalities and proliferating fracking operations create severe pressure on agricultural producers.
• Increasing climate chaos. With global warming, seasonal weather patterns are becoming unreliable, forcing producers to rapidly attempt to adapt their cropping plans. Extreme weather events are also increasing, such as the rains and flood of September 2013, which inundated more than 28,000 acres of cropland (mostly conventional) and 39,000 acres of pastureland and destroyed much of the 150-year-old ditch irrigation system. Climate projections indicate that these trends will worsen in the coming decades.
• Lack of trained labor. Every year, food producers must face the increasing challenge of hiring skilled workers on a seasonal basis. Immigration restrictions have greatly constricted the traditional supply of labor coming from Mexico.
• Competition with marijuana industry. Legalization of both medical and recreational cannabis in Colorado makes this cash crop an attractive priority for growers, governments, and investors. Most available warehouse space in the region has already been snatched up, compelling marijuana entrepreneurs to erect large-scale greenhouses on agricultural land. Because of its revenue potential, marijuana production is often prioritized over food production.
• Bioregion not ideal for land-based food production. Most of the Colorado Front Range is in a semiarid short-grass prairie bioregion, where shale-based soils are sandy and more conducive to animal grazing than vegetable production. Native populations followed the buffalo through this area but scarcely relied on any kind of agriculture for food. Even though these factors arguably make the Front Range a less-than-ideal location for a population of 4.5 million people, the region is expected to increase to more than seven million by 2050168. Feeding such an increasingly urban population as locally as possible will become an enormous challenge, but one that will also create tremendous opportunity for economic development.
• Lack of financial incentives. Low farm profits and limited infrastructure for distribution and marketing discourage many producers from attempting local food production at any appreciable scale.
These challenges are, of course, not limited to Colorado.
CEA offers ecologically sensitive food production through a combination of ancient and recent technologies that focus on the preservation of waste streams into productive resources.
—EMMANUEL PRATT, SWEET WATER FOUNDATION
In this context, controlled-environment agriculture (CEA)—whether via hoop houses, low and high tunnels, hydroponics, aquaponics, or aquaculture—offers advantages and benefits (ecological, economic, and social) that are only beginning to be recognized in this country, though other nations have adopted CEA extensively. For instance, in the Netherlands, only 0.5 percent of arable land is used for greenhouses, but the production value is 22 percent of total Dutch agricultural production value.169 Around the world, the top ten greenhouse producers are China (with an estimated 2.8 million hectares), followed by Korea (57,000 ha), Spain (52,000 ha), Japan (49,000 ha), Turkey (33,500 ha), Italy (26,500 ha), Mexico (11,800 ha), the Netherlands (10,300 ha), France (9,600 ha), and the United States (trailing with 8,400 ha—only about 21,000 acres).
Nevertheless, adoption of CEA is beginning to accelerate in the United States. According to a 2013 Rabobank study, while “greenhouse produce is estimated to only represent 1 to 2 percent of overall U.S. fresh fruit and vegetable production,” certain crops, like greenhouse tomatoes, today account for as much as 70 percent of sales.
While still in its early stages, “the U.S. greenhouse industry has been steadily growing over the past decade,” says the Rabobank study. “This growth, driven in part by the need for more intensive production due to limited land, water and labor, has pushed sales over $3 billion and is estimated to reach over $4 billion by 2020.”
The local food industry has generally been slower to adopt CEA than commercial agriculture. Some of the earlier commercial-scale greenhouses were developed in conjunction with supermarkets, mostly growing commodity tomatoes (not organic).
• Small footprint. In terms of output, greenhouse production can utilize as little as 1 percent of the land needed for equivalent land-based production. With farmland increasingly scarce and expensive, this is a tremendous advantage.
• Energy efficiency. While greenhouses are often considered energy intensive, the reality is that they use far less in fossil fuels than soil-based market farming methods. In the future, agricultural engineers anticipate that greenhouse production without fossil fuels can be achieved in the future by using heat pumps, geothermal heat, waste heat from other industries, and green electricity. Current natural gas consumption, used for heating greenhouses in cooler weather, can be offset by lower fuel needs in other areas—growing for local customers reduces or eliminates the need for refrigeration and shipping
• Water conservation. While the industry literature regularly claims that greenhouse production uses less than one-tenth the water used by soil-based production, that figure is actually conservative. Much of the water in a CEA unit is recycled within the system. Evaporation is extremely limited. Rainwater capture and near closed-loop irrigation recirculation can further improve water conservation.
• Reliable year-round supply of produce. CEA breaks the cycle of seasonality, which often forces buyers to rely on imported products.
• Environment control. CEA systems are designed to maintain near-optimum climatic and nutritional conditions for the plants being cultivated, thus eliminating most of the uncertainties of commercial-scale food production.
• Input control. Plant nutrients, carbon dioxide, light, and water can all be tightly controlled (via computers) for maximum efficiency and quality and to maximize the photosynthesis process.
• High production capacity. High-tech hydroponic greenhouses are capable of annually producing in the range of $1 million in revenues per acre—roughly two orders of magnitude greater than soil-based market farming.
• Stable nutrient composition. Consistent product quality, particularly in terms of nutritional value, is difficult to achieve in soil-based production. CEA provides an unmatched level of stable nutrient composition.
• Pest and disease control. Using biological agents, it is possible to keep production free from synthetic pesticides, herbicides, and fungicides.
• Waste reduction. Other than organic plant residues, this production method does not produce waste materials.
• Reduced labor costs. Greenhouse production is far less labor intensive than soil-based production.
• Scalable. Production can easily be scaled to meet growing demand for local, sustainably produced food—especially in urban settings.
• Ultra-short supply chain. Greenhouses can conveniently provide local populations with their daily supply of vegetables and nutrients. Delivery to customers can take place within hours of harvest, eliminating the 1,500-mile transport chain that imported produce travels through.
• No agricultural runoff. This type of food production is basically done in closed-loop systems, thus greatly reducing pollution.
• Dramatically reduced delivery time. Greenhouses can be placed near population centers, so food can be purchased and consumed within a few hours of being picked.
• Capital intensive. Capitalization of greenhouses averages approximately $1 million per acre.
• Training required. Successful greenhouse production demands skill and experience, as these are sophisticated facilities. To keep up with market demand, adequately training new growers will be a high priority.
• Limited crop variety. The most common greenhouse crops are tomatoes, leafy greens, microgreens (especially for restaurants), cucumbers, peppers, herbs, green beans, and squash. Strawberries and raspberries are likely to be popular in the near future. Root crops and melons are usually impractical.
• Carbon dioxide must be added as a system input. Plants can quickly reduce carbon dioxide concentration in the closed greenhouse environment, which can slow plant growth. It must be introduced and monitored.
Both producers and eaters are increasingly concerned about the quality of their food, and in recent years, they have demonstrated a preference for local and organic food, traditionally produced in soil. Hydroponic food production is mildly controversial and often misunderstood. Greenhouse producers are often asked if their produce is organic. Lufa Farms in Montreal provides valuable insights into these concerns.
Short answer: no. We practice sustainable hydroponic agriculture by using no synthetic pesticides, herbicides, or fungicides; capturing rainwater and recirculating 100% of irrigation water; using half the energy to heat as a ground-level greenhouse; composting green waste; choosing cultivars for their taste and nutritional value instead of durability; and delivering our produce on the same day it’s harvested to eliminate waste.
From the outset, our mission has been to grow food where people live and grow it more sustainably. One of the major challenges when we started was to decide whether we wanted to use soil-based methods (which are eligible for organic certification in Canada) or greenhouse hydroponics (which currently are not).
In the end we decided to focus on hydroponic growing, even though these methods are not eligible for organic certification, to minimize our environmental impact. Doing so has allowed us to implement systems that recirculate 100% of irrigation water in our greenhouse. Some of the nutrients we use are mined (e.g., iron, potassium, etc.). One reason that hydroponics has yet to be certified organic in Canada is because the mined nutrient salts are nonrenewable, but our ability to recirculate cuts down on an estimated 90% of nutrient usage versus standard hydroponic agriculture. By using drip irrigation and other hydroponic methods, we’ve created a completely closed irrigation loop that grows highly nutritious and incredibly tasty vegetables year-round while keeping water and nutrient use to a minimum.
Early on, we made the decision that we would not use any synthetic pesticides, herbicides, or fungicides in our cultivation. Instead we adhere to strictly sustainable cultivation methods, using only biocontrols (like ladybugs) and biological products (like algae) for pest and disease management.