A study conducted by: Anisa Buck, Daniel Dine, Stacy Goldberg, Vani Gulate, Vivek Iyer, Ben Jacob, Eugene Kang, Roger Kim, Jennifer Montes, Pearl Moy, Anita O'Connor, Katerina Paraskevas, Rebecca Tatum, Carrie Teicher, Janice Turner

Course Director: Dr. Dickson Despommier; Columbia University, Spring 2004

Preface

The Vertical Farm is only a concept at present. What follows is an extension of that idea as it relates to the real world. The project for this year’s (2004) Medical Ecology class was:

“Design a vertical farm that can produce enough calories (2,200/person) for a population of 50,000 people”.

This report documents the fruits of their labors.

Introduction

Our vertical farm consists of a self-sustaining building or an interconnected network of buildings in a modern city that produces food and assists in waste management for its urban population. In an effort to minimize the negative environmental effects that growing urban populations continue to have on our planet, the Vertical Farm Project combines established and cutting-edge technologies to create a dynamic model for urban farming. A model for a Vertical Farm has been developed and designed to feed 50,000 people and its parameters are presented in this document. The urban environment selected to model the Vertical Farm is New York City’s Island of Manhattan.

Overview

It is a simple fact that everyone needs to eat. However, a consensus on who gets to eat, how much they get to eat, what we choose to eat, and how we chose to grow our food is not so easily reached when operating under the reality of living in an environment of fixed resources. The earth is a very different place than what is was at the dawn of human civilization. Of the dramatic changes the earth has undergone at the hands of humans, perhaps the most powerful are those due to population growth and the formation of large urban centers. Debates as to whether the earth has already exceeded its carrying capacity seem, for many, an academic exercise. However, a look at our current environment tells us that questions about sustainability and longevity are not simply a thought exercise.

A very real and tangible growing concern that we face today is how we will manage to feed another 3 billion people expected to populate the earth in the next 50 years, especially given the huge inequalities in food distribution that currently exists. The food requirements for people in large urban centers seem to be an especially difficult problem to solve. Although they only cover 2% of the Earth’s surface, cities consume 75% of the Earth’s resources.ⁱ Today, some 60 % of the earth’s population lives in or near an urban center. In addition, it has been conservatively predicted that over the next 50 or so years, that figure will go up to 80 % or higher, and the number of humans living in urbanized centers is expected to increase by 2% every year this century.^{ii, iii} The need to provide food for these rapidly growing urban centers may become increasingly complicated in the future.

Background

Half of the world’s population currently lives in cities. By 2025, urban populations are expected to increase to 65% of the global population.^iv One major issue related to rapid urban growth is food production. Metropolitan areas rely on agriculture, produced in rural areas and, as of 2001, 40% of the world’s land area was used for agricultural (crops and grazing) purposes.^v

Urban populations have never had to face the effects that large-scale rural agriculture demands of the environment. Environmental impacts from standard agricultural practices include, but are not limited to, deforestation, reduction of natural resources, dry land salinity, high water consumption, and pesticide, herbicide, fossil fuel consumption, and fertilizer contamination. The transportation and refrigeration of food from rural to urban areas also results in the consumption of significant amounts of fossil fuel producing environment-damaging amounts of greenhouse gases.^vi

Our current methods of agricultural production are rife with problems that have to be addressed. The deleterious effect of current agricultural practices on drinking water supplies, both on the surface and below ground, is just one example. “Humans already use more than half of all accessible, renewable fresh water, and 70-80 percent of that is used for modern agriculture, more than any other human activity. Currently, over 40 percent of world food production occurs on irrigated land”¹. This puts an enormous strain on our current water supply.

What if the urban landscape were edible?

An alternative to conventional (rural) agriculture is urban agriculture. Urban agriculture establishes an agricultural practice in or near an urban setting. It develops modern, sustainable agricultural systems that establish productive, reusable, self-contained waste and nutrient cycles in metropolitan settings.^vii They can include raising food crops, horticulture, poultry, fish farms, and other livestock in public and private open spaces, vacant lots, or, as in the case of our Vertical Farm, in “green” buildings.^viii

Historically, agriculture arose in populated areas and only rapid population growth and increases in demand forced animal and crop production out into adjacent rural areas. Agriculture remained a rural activity until recently when, as in the United States today, 30% of agricultural production originates in metropolitan areas. This increase in urban farming is not limited to the United States. Urban farming contributes to 15% of world food production and is expected to grow to 33% by 2005. In addition, urban farming makes economic sense according to the U.S. Urban Gardening program that estimates that a $1 investment in these projects yields $6 of produce.

These are not simply issues of supply. There are numerous public health concerns inherent in any mode of agricultural production. Irrigation and the subsequent creation of standing water sites in tropical and sub-tropical ecozones has led to increased rates of infectious diseases such as malaria and schistosomiasis by promoting the habitats for their vectors and intermediate hosts (snails) to flourish. Runoff from agriculture into lotic and lentic ecozones worsens these problems by destroying the quality of the drinking water that is still available. The clearing of vast amounts of land for the growing crops and the resultant deforestation that has occurred on a global scale is another problem of current systems. Deforestation exacerbates and further contributes to the increasing rate of global change, a problem for which we have yet to find solutions. Erosion (wind and rain) of cleared lands removes fertile topsoil for growing crops, reversing any benefits that were temporarily achieved.

In addition to how we specifically choose to grow food, there is the issue of transportation of produce. In most urban and suburban centers where development is the norm, land available for agriculture is negligible, if present at all. As a result, most of the food we buy in our grocery stores has had to travel long distances to reach these markets. Diesel exhaust contributes to increasing rates of respiratory diseases as well as reducing visibility. In addition, the fuel requirements of transportation for growing food in this manner makes us even more dependant on foreign sources of oil and its potential ramifications.

Unfortunately, cities have traditionally behaved as if they were separate and distinct entities from nature. Living in urban environments in this mode deprives us of the opportunity to envision built environments that can exist in balance with adjacent functional ecosystems. The ecological footprint analysis of major cities demonstrates that the vast majority of high-density human settlements no longer have boundaries that coincide with land needed for their daily activities. The agricultural inputs for these cities can be counted as one of the major reasons for this. “Sustainability can only be achieved when cities are approached as systems and components of nested systems in ecological balance with each other.” This makes it clear that we must begin to re-integrate our urban agricultural activities with natural processes. Such balanced integration increases the efficiency of resource use, the recycling of wastes as valuable materials, and the conservation of energy.

In order to assist in reaching this goal, we propose the concept of the vertical farm. The idea is to grow food vertically within technologically advanced building sites rather than horizontally, thereby reducing the vast amounts of land from agriculturally associated damage. In addition, by taking an ecosystem approach to farming and placing a premium on integrated farming techniques, much of the wastes generated by traditional farming methods can also be avoided. This ecosystem approach will allow us to bring our ecological footprints back in line with our physical boundaries, using modern synergistic methods to create efficiencies while maintaining necessary production of foods for urban populations.

Conceptual Objectives

By establishing a successful urban farming model, the goal is to improve the city’s quality of life. A Vertical Farm in a neighborhood would stimulate the local economy and build a stronger community. A Vertical Farm would have a beneficial impact on low- to middle-income, unemployed, or underemployed in a community by providing jobs and food at a reasonable price. Urban farmers also tend to be women and therefore a Vertical Farm would act to empower them.

The Vertical Farm project is working towards an urban model for food production that would significantly reduce rural agricultural land use. A reduction in agricultural land use minimizes runoff that includes pesticides, herbicides, and fertilizers. Vertical farming would therefore greatly diminish the impact of these noxious chemicals on the public’s health and on the functioning of terrestrial and aquatic ecosystems. Other beneficial environmental effects are numerous and could include a decrease in global warming by returning farmland to hardwood forest. More land that exists as free space also will assist in restoring and maintaining biodiversity. In addition, the vertical farm would use community wastewater to safely irrigate crops and aquaculture. If designed properly, the vertical farm could remediate black and gray water back into drinking water.

This project explores the development of a cost effective, self-sustaining model for vertical farming. The specific goals for this year’s Vertical Farm project include:

1. Design a building that will produce enough of a wide variety of food items to feed 50,000 people.
2. Include organic poultry and fish production with an emphasis on ethical treatment.
3. It must have zero net emissions.
4. The farm must convert black and gray water into drinking water and recycle all evapotranspiration water vapor.

Critics of urban farming have raised concerns regarding the establishment of plant and animal diseases, pests, noise, and pollution. When developing our model, these concerns were considered and plans were implemented to effectively manage these issues.

Nutritional Information

The Vertical Farm is designed to meet the basic nutritional needs of a diverse population of 50,000 people, presumably (in this case) situated within the city of New York.

Calculations of projected nutritional content were based largely upon the United States Department of Agriculture’s Center for Nutrition Policy and Promotion (CNPP) guidelines published as the ‘Food Pyramid.’ The CNPP was created in the U.S. Department of Agriculture on December 1, 1994, and is “the focal point within USDA where scientific research is linked with the nutritional needs of the American public”.

Fig A. Food pyramid

Nutrition guidelines vary according to the specific subpopulation of food consumers: males and females, children, adolescents, and adults, and groups with particular physical needs and activity (pregnant women, athletes) all have particular nutritional needs. For the purposes of this study, we chose to target an average adult nutrition intake with the understanding that a balance of needs would be met within simple variation of the proposed diet. The target nutritional intake was 2200 calories daily, the rough equivalent of intake for an adult woman or teenager. While males (active adults and teens) should have higher caloric intake, while other populations (children, infants, older women) will have lower intake. Therefore a target of 2200, also above the proposed minimum USDA nutritional guidelines seems like an adequate average.

The food pyramid was developed over a ten-year period of nutrition research and was revised at the CNPP and is updated with corresponding food intake suggestions on a regular basis. It is referenced as a medical education teaching resource by the American Medical Association (AMA), and is also produced (as AMA recommends) in configurations appropriate for specific minority subgroups with different dietary preferences.

Built to be a simple and understandable tool, the pyramid breaks daily food consumption into six major groups: Bread/cereal/pasta; Fruits; Vegetables; Meat/Fish/Poultry/Eggs/Nuts; Milk; and Fats and Oils. Daily consumption is recommended in terms of a number of servings, with a simple explanation of serving size. For our purposes we use the food pyramid as presented. (see Fig A)

The proportions of recommended daily intake are:

The Vertical Farm is not a dairy farm; thus, milk products will not be produced or otherwise created in this setting. For nutritional purposes, we estimate that the macronutrients (protein, carbohydrates, fats) provided by milk products will be instead consumed as chicken, fish, beans, or eggs. Calcium may be obtained in small proportions from other parts of the diet, such as fruits or vegetables, but may also be provided as a supplement.

The food pyramid is designed to meet the macro and micronutrient needs in a daily diet. Thus, a person who follows the guidelines proposed will also intake the daily required amount of vitamins and minerals.

Space Calculations

The vertical farm’s ability to conserve land now in use for traditional agricultural methods is what makes this project unique. What are the space requirements for attempting to feed a population of 50,000 people with food grown vertically? The vertical farm team believes that this goal can be accomplished in a building that fits into one city block.

Using the approximation of one numbered block as equivalent to one-twentieth of a mile (or roughly 528 feet), a short block is 264 feet long. An avenue block (estimated as one-fourth of a mile) is 1320 feet long. A full square block is 348,480 square feet in area.

What are the relevant constraints to building size? Engineering constraints will be important; for our purposes, however, we focus on the specific needs of the plant and animal growing systems included in the vertical farm. In order to meet basic engineering considerations we plan a building that fits within the realm of the possible, compared to other existing New York City structures.

T he farming components of the vertical farm will require adequate lighting for plant growth. We expect to provide artificial lighting in order to meet the energy needs of the plants, particularly those located within the interior of the building. As we also intend to stack the plants whenever possible, growing multiple layers per floor, vertical light will not filter as cleanly, requiring additional light supplements. In order to maximize the light that can pass through the building’s external walls, however, we prefer to engineer a vertical farm with a greater outer surface area to internal volume ratio. A taller, skinnier building will have more external surface area than a shorter, stubbier one.

The calculations presented include two space estimates, one for a larger ‘footprint’ of 250,000 ft² per floor (250 ft x 1000 ft) and the second for a smaller ‘footprint’ of 90,000 ft² per floor (250 ft x 360 ft). Whenever growing methods supported stacking layers within a 10-ft vertical floor, we estimate an area with 3 layers of growth per floor. A brief estimate of the total space required by each of the major agricultural methods that will be used is given below.

Ultimately, we estimate the vertical farm to fit comfortably within a city block. The smaller building will be 49 floors tall; the larger, only 18 floors.

Production Specifications

Chicken Production for Eggs & Meat

Chicken production is an efficient option for protein. The efficiency of chicken production is the result of high yield of offspring each year (up to 300 eggs per year), the relatively short time required to reach maturity (approximately 10 weeks), and efficient use of feed (broilers can convert 2 kg of dry feed to 1 kg of weight). The mortality rate of chickens ranges from 3-18% and depends on whether a chicken is brooding, laying, or simply growing.

A number of chicken breeds may be suitable for production in a vertical farm. The Leghorn and Australorp are popular varieties for egg production due to their high egg production, cold hardiness, and ability to live in confinement. The Leghorn is particularly noted for its high egg production (up to 300 eggs per year), and is therefore recommended for use in a vertical farm. Although not as common as the Leghorn or Australorp, the Dominique may also be suitable for the vertical farm. This dual-purpose breed provides meat and eggs (up to 170 per year). The Dominique, believed to have originated in New England, is also cold hardy and lives well in confinement.

The following sections will describe the suggested target yields, system requirements, and wastes generated in producing chicken meat and eggs (broilers and layers) to feed 50,000 people for one year in a vertical farm.

Target Yield

Chickens and their eggs are a good source of protein and fat. One egg provides 74 calories, 6.29 grams of protein, and 4.97 grams of fat. One 3 ounce serving of chicken provides 183 calories, 15 grams of protein, and 13 grams of fat. We assumed that each person would consume three eggs and four 3-ounce servings of chicken meat per week. In order to feed 50,000 people over a year based on these serving assumptions, the vertical farm must produce approximately 282,488 broilers and 26,000 layers, which would provide a total of 2,486,798,802 calories (see calculations in appendix).

System requirements for Chickens

I. Space

To accommodate 26,000 layers and 282,488 broilers, approximately 95, 232 and 1,694,688 square feet of space would be required, respectively. These calculations were based on the assumption that each layer requires 3.7 square feet of space and each broiler requires six square feet of space.

In addition to adequate space, chickens also require adequate ventilation systems, air conditioning in summer, and heating in the winter. For year-round egg production, it is also necessary to provide ample lighting for layers. Some experts suggest that one electric bulb per 40 feet and a south-facing window will be adequate to ensure year-round egg production. Figure 1 is a suggested floor plan for layers.

Fig. 1- Floor plan from http://www.ext.vt.edu/pubs/poultry/factsheets/61881.html

II. Feed requirements

As mentioned above, chickens are relatively efficient in converting feed to body mass. Using the estimate of 2 kg of feed per 1 kg of body mass, approximately 208,000 and 2,562,797 pounds of feed would be required for layers and broilers, respectively.

III. Infection/Disease Control

Chickens are prone to several diseases. Common bacterial diseases are infectious coryza, fowl cholera, avian mycoplasmosis, mycoplasmagallisepticum, mycoplasma synoviae, and mycoplasma meleagridis. Common viral diseases are fowl pox, Marek’s disease, infectious bronchitis, and Newcastle disease. Recently, a new avian influenza strain, H5N1, has resulted in human cases in China and elsewhere in Southeast Asia, and is associated with a high mortality rat (see: http://fas.org/promed/, then go to Emerging Infections).

To prevent the introduction of these kinds of infectious diseases, the vertical farm should practice stringent sanitation and monitoring guidelines, as well as institute on-going vaccination programs for viral diseases such as Newcastle, fowl pox, avian influenza, and fowl cholera. Vaccination is common in many chicken farms and may involve administration via drinking water or injection. We recommend at least biweekly monitoring of the chickens by veterinarians and daily monitoring by trained employees.

Waste Management

The estimated amount of waste generated annually by layers and broilers is 40 and 2.5 pounds, respectively . Based on these estimates, the suggested number of layers and broilers will generate approximately 1,040,000 and 706,220 pounds of guano, respectively. Guano is predominantly composed of phosphorous, nitrogen, and potassium and may be used as fertilizer. , A portion of the chicken guano will be used to feed tilapia. The remainder could be used for methane generation. Collecting and storing guano safely prior to use will require innovative new engineering approaches.

Fish Production

Tilapia (Oreochromis spp) is a hearty freshwater fish whose popularity and utility continue to grow relative to other farmed fishes such as catfish and trout. Native to the Middle East and Africa, this fish grows rapidly within a range of environments, with a high tolerance for conditions including relatively low dissolved oxygen and high turbidity, and with a broad range of dietary preferences. Tilapia is the second most cultured group of fish in the world. It has a mild, sweet flavor, and the meat is white, lean, and has tender flakes. (Cabbage Hill Farm: Tilapia 2004) It is high in protein, low in fat, with 19.7 g protein and 2 g fat per 3.5 oz (100 g) serving. It is increasingly an ideal fish for farmed situations in both indoor and outdoor settings, within the United States and throughout the rest of the world.

Because interest in tilapia aquaculture is on the rise within the US, numerous research and agricultural stations have investigated methods of culture ranging from small (8 foot diameter) indoor tanks to multi-acre outdoor ponds. More established and tested systems include those pioneered by Dr. Mark McMurtry at North Carolina State, Dr. James Rakocy at the University of the Virgin Islands, and the ‘Sperano System’ a modified version of the North Carolina State system developed by Tom and Paula Sperano.

The Vertical Farm intends to provide a steady flow of food throughout a calendar year despite external weather conditions, within a largely indoor environment in a multi-story building. These constraints indicate the need for fish farms that can be harvested on a regular basis, contained within one or more building floors, and maintained throughout the year with regulated conditions. The UVI system is an ideal model for these conditions. First, it contains multiple, small tanks that can each be grown and harvested on a staggered scale in order to ensure regular provision of fresh fish to the community. Second, these multiple tank units may be more easily fit into a vertical, rather than horizontal, space, and more likely combined with other farming objectives (i.e. hydroponic vegetable culture; raising chickens or produce) in a hybrid system. Finally, the smaller tanks, due to larger surface area to volume ratios, will be easier to manage and maintain in a regulated indoor environment. The specifications for the UVI system are provided as a model for the fish-farming component of the Vertical Farm.

The fish farm is designed to provide a component of the total nutrition. Calculations were based on the assumption that each individual will consume an average of 100g of fish per day, based on the American Medical Association recommended daily allowance of 2-3 servings from the meat/fish and dairy food groups and in conjunction with consumption of poultry eggs and meat. We realize that this is a somewhat unrealistic expectation, but this is a useful staring point in considering sources of meat. This fish portion fulfills the requirements for all major macronutrients including protein, energy/carbohydrates, energy/fat, and multiple vitamins and minerals.

The following calculations describe the target production goals for the fish farm, the farm’s energy inputs and outputs, and its space and engineering demands. Calculations are based on the average inputs and outputs for one tank of fish, which are then multiplied to provide for the target population.

Target Yield

In the USVI system, one tank measures 8’ in diameter by 4’ deep. The tank is stocked with 800 30g male tilapia fingerlings, which will grow for 6 months before harvest. Mortality estimates range from 10% to 25%; for our purposes we assume the higher mortality of 25%. The fish are harvested when they reach an average target mass of 450 grams. Edible filets constitute 40% of this live weight. Based on a target yield of 600 fish (75% of 800 fingerlings) at 450 g per fish, one tank harvest should provide:

.45kg x 600 = 2700kgs x .40 = 108 kg edible fish

A community of 50,000 people consuming 100g of fish per day will require 182.5 million grams, or 182,500 kg of fish filet per year. If each tank yields an average of 108 kg edible fish, then 1690 tanks per year will meet the needs of the target population. However, the fish growing cycle lasts only 6 months; therefore, the Vertical Farm fish component will contain 850 tanks, each of which is used twice throughout the year.

Inputs: Fish Nutrition

Tilapia grow quickly and require energy sufficient to ensure their steady and healthy development. Tilapia have been selected by us because of their ability to consume a varied diet including algae, agricultural wastes, and commercial or supplementary fish feeds. Conservative estimates indicate that this fish species converts up to 30-50% of food intake to body mass until full grown. Food formulations shift from relatively higher protein/ lower carbohydrate/fat diets during the early months of growth to progressively lower protein/ higher energy diets as fish achieve maximum growth. Regardless of the formulation, the growing fish will be fed roughly one and one-half times their average daily body weight throughout the course of their lives.

The formulation of food may vary according to the design of the farming system. The USVI model recommends the purchase of pre-formulated food and uses a concentrated feed pellet (the brand is “Farina 32% Tilapia Chow”) that is necessary to promote a fast growth rate (The cost of the feed is $.22 per pound. Feed is usually bought in 50-pound bags). While the USVI system is designed to provide nutrient-rich effluent for potential hydroponic vegetable growth, other hybrid systems base their fish feeding in part upon the wastes from other livestock, such as fish, chickens, or ducks. ,
Earlier calculations estimated that each tank would produce 270 kg of live fish weight, of which 108kg or 40% was edible. Using this same estimate, one tank of fish should consume two and one half its total weight in food, or 675 kg, in order to reach this target weight. Each individual fish (harvested at .45 kg or 450 grams), would consume 2.5 times that amount, or 1,125g, of which 40% becomes increased body mass, 20-30% is used for energy and maintaining body functions, and 30-40% is waste.

The total population of 1690 tanks would require approximately 1,140,750 kg of food throughout the year of growth.

Waste Management

The primary waste products are urea and solid excrement which accumulate in the tanks. Waste products will be cleaned and concentrated using an adjacent settling tank to gravity-settle solids and a filtration system to remove dissolved wastes from the water.

The twice-filtered water may be recycled for use as a fertilizer or as a source of nutrients for growing algae in a hybrid system that includes a hydroponic farming component in which nutrient-enriched water grows vegetables and fruits such as lettuce, tomatoes, and strawberries. In a self-contained or green water system, a small percentage of these wastes may still be recycled back into the fish tanks (or left there to begin with) as a nutrient source for algal growth that is, in turn, a source of food for the tilapia. In the USVI Green Water Tank system, between 10-15% of the waste-grown algae contributes as feed.

Waste calculations are approximations at best. Craig and Helfrich estimate that total wastes will include a combination of 10% solid and 30% liquid waste. Thus, the 1690 tanks of fish may be estimated to produce an average of 456,300 kg of waste yearly, or roughly 40% of the total food input for the fish. An alternative means of estimation is given by J. Rakocy based on the assumption that 35% of fish feed will be solid waste or sludge. The estimated waste in this case would be 1,140,750 kg feed x 0.35 = 399,262 kg of waste. Since this calculation is based on the use of dry pellet food, the actual bulk waste, now containing water, will be as much as 50 times greater, or 1,996,312 kg.

System Requirements: Space and Electricity

Space

As stated earlier, the tanks are 8’ in diameter and 4’ deep, filled with a volume of 1250 gallons of water. Each tank will occupy roughly 50.24 ft²; 850 tanks will occupy 42,700 ft² without considering additional inter-tank room or cleaning equipment.

Water cleaning equipment and settling tanks require additional space: the USVI system designates two 4’ diameter solid settling tanks and two 2’x 6’ rectangular filtration tanks for every group of four growing tanks. We estimate an additional 5,000 ft² space in and around the tanks. Thus, cleaning equipment adds:

Solid Tanks: 3.14 x 4ft = 12.56 x 212 tanks x 4 = 10,650 ft²

Filtration Tanks: 2ft x 6 ft = 12 ft x 212 = 2544 ft²

Cleaning Space: 5,000 ft²

The fish farming operation will also require a space for fish food storage (2000 ft), additional waste management (3000 ft). These calculations do not include estimates of weight and any related engineering constraints. The total space that is estimated for the fish farming operation is 60,894 ft².

Electricity

Tilapia grow in warm-water conditions with water in an optimum range from 82° to 86°F. This water may be passively heated and cooled by the air within the vertical farm if the environment is relatively closed and controlled. Alternatively, the water temperature may be maintained independent of the ambient air temperature through individual heating and cooling systems linked to each tank. Given the desire to provide year-round food crops, the indoor air temperature will likely be maintained at suitable conditions for much if not all of the year. Some electricity input will be used to ensure that the water temperature is maintained within livable limits, if only as a backup to more passive temperature regulation.

Oxygenation is more central to fish survival and culture. Tilapia require a minimum dissolved oxygen level of 3 parts per million, a demand that must be artificially provided within the crowded tank environment. Algal growth and bacterial digestion will further raise the biological oxygen demand (BOD) and so require additional oxygenation. Electric pumps will be used to oxygenate each individual tilapia tank; the electricity could, however, be provided by a methane-based digester located within the vertical farm and designed to recycle the solid and liquid wasted produced by animal and plant farming.

Habitat Conditions

Tilapia grow best in water with a pH of 7; as nitrogenous wastes (urea, uric acids) build up and make the water acidic, neutral pH is maintained by added buffers such as KOH or (Ca(OH)2), added daily or every other day. Iron is supplied through the addition of an iron chelate once every three weeks and the recommended amount is 2ppm.

Hydroponics

The word hydroponics is derived from the Greek hydros, meaning water, and ponos, meaning labor, or literally, water working. Hydroponics dates back to the famous Hanging Gardens of Babylon. The Aztecs also used hydroponics as a practical method of gardening and conserving water.

Hydroponics is the most environmentally friendly method of growing plants of many kinds. The process does not strip the essential elements, technically the livelihood, from soil, therefore removing the risk of erosion and allowing for more land to be returned in and maintained to its natural state. It is also cheaper and more efficient than soil gardening.

There are many other advantages to using hydroponic systems. The soil not only supports plant life but also supplies the substrate for bacteria and some pathogens harmful to humans, such as the geohelminths (Trichuris, hookworm, Ascaris) and several species of protozoa (Giardia and Entamoeba). In addition, there are numerous species of plant nematodes that can severely damage the health of a plant, even leading it to its death. Weeds also grow as opportunists, competing with the crop plants for nutrients and space. Using hydroponics eliminates most of these problems, greatly improving plant health and vitality, while removing health risks from those tending the plants.

Plants grown hydroponically have the same general requirements for optimal growth as do those grown in topsoil. The major difference is the method by which the plants are supported and the medium, which contains the macronutrients needed for growth and development. These include organic solutes, phosphorus, potassium, calcium, and magnesium. Micronutrients are also vital for optimal growth, but are required in smaller amounts. These include iron, manganese, boron, zinc, copper, molybdenum, chlorine and its byproducts.

Hydroponic systems also provide both constant temperature and light necessary to maximize crop yield. Plants grow at a limited temperature range. Temperatures that are too high or too low result in abnormal development and decreased growth. Warm-season vegetables such as eggplant and tomatoes grow best between 60 degrees and 80 degrees F. Cool season vegetables such as lettuce and spinach, should be grown between 50 and 70 degrees F. Hydroponically grown vegetables need at least 8 to 10 hours of direct sunlight each day to grow well. A poor substitute for sunlight is artificial light, which is actually not enough to grow crops.

Vegetables grown in a hydroponics system won’t do as well during the winter as in the summer. Shorter days and cloudy weather reduce the light intensity and thus limit production. Most vegetables do better if grown in January to June, or from June to December.

Hydroponics is successful because:

1. It eliminates the possibility of acquiring soil-based plant pathogens.
2. Like humans, plants grow best when not under stress. In hydroponics, the crop is allowed full access to water for both growth and transpiration.
3. In soil-based agriculture, optimizing the supply of essential elements is an intricate procedure involving sophisticated soil management strategies. Hydroponics eliminates the guesswork by providing a balanced formula of nutrients, made for the sole purpose of optimizing plant growth.
4. The pH of the water must be maintained for the crop to be successful. In a hydroponics system, the pH is tested regularly and corrected with the addition of acid or alkali when necessary. Most systems use automatic monitoring and control through correction, during which pH is adjusted to a 0.1 pH resolution, a degree of control, which is impossible to accomplish in soil-based farming.
5. The above process results in improved plant health leading to impeccable growth cycles resulting in highly nutritious and delicious produce.
6. With hydroponics, water is used efficiently as it is the only water that the plans consume.
7. Hydroponically grown crops are in top condition, and require no application of herbicides or pesticides.
8. Today’s market, business atmosphere, and society in general place high demands on the grower, whose crop productions must yield high profits. Hydroponics leads to cost effective crop production involving higher quality products, higher yields, automatic watering and feeding, weed control, extended growth seasons, physically and nutritionally clean products and reduced crop management labor costs.

In summary, hydroponics is the most intensive method of crop production currently in use. While using the most advanced technology, the results are highly productive, respecting the land, use of water and protecting of the environment.

Types of Growing Systems

I. Nutrient Film Technique

This is the most rapidly evolving type of hydroponic system. A thin film of nutrient solution flows through the plastic lined channels, which contain the plant roots. The wall of the channels are flexible to permit them being drawn together around the base of each plant to exclude light and prevent evaporation. The advantage of this system in comparison to others is that a greatly reduced volume of nutrient solution is required, which may be easily heated during winter months to obtain temperatures necessary for root growth or cooled during hot summers in arid or tropical regions.

There are many types of water culture or aquaculture (hydroponic methodologies).

These include:

1. Aquaculture
   This water culture method is the simplest to set up and the roots are totally immersed in a nutrient solution. The disadvantages are the requirements of large amounts of water to grow each plant and the aeration necessary for the solution. The advantage is that the actual design is up to the planner. Basically, the system must provide means to support the plant above the solution and aerate it, and prevent light from reaching the solution, preventing the growth of algae. The typical size of a standard tray is 6 to 12 inches deep, 2 to 3 feet wide and as long as one wishes it to be. A large tomato plant should be grown in a container that holds two gallons, as the solution in a smaller container will be used up quickly. Lettuce can be grown in smaller containers, as they are small plants and are able to support themselves, whereas plants with vines such as cucumber and tomatoes need to be supported. The nutrient solution must be changed every two weeks when the plants are small and once a week when they are nearly full grown. Additional water must be added to make the solution constant.
   
2. Aggregate culture
   Sand or gravel is preferred in a water culture because these substances help support the roots. A nutrient solution is held in a separate tank and pumped into the aggregate tank to wet the roots. After the flooding of the aggregate, it is drained for aeration. Water and nutrients thus stick to the roots, supplying the plants until the next flooding. The solution is pumped to one inch of the surface and then drained. Algae growth is not widespread if the top surface of the bed is dry. The best aggregates are silica gravel, granite, basalt and smooth river-bottom rock of the inert kind lacking in calcium. Larger aggregates require frequent flooding and smaller aggregates do not drain well. Perlite, Styrofoam, and even crushed marbles have all been effectively used for this purpose. The aggregate is flooded for ten minutes and then drained for no longer than thirty minutes.
   
3. Aeroponics
   In this unique hydroponics configuration, the roots are grown in a closed container. Mist laced with essential nutrients creates a constant film, keeping the roots moist. The container may be of any design and is usually lined with plastic. Lettuce and tomatoes are grown in an A-shaped container to make the best use of the space and the available light.
   
4. Continuous flow systems
   Commercial hydroponic systems provide a continuous flow of nutrients to the plants. The nutrient solution is held in a tank and pumped or allowed to flow by gravity, providing the plants with all essential requirements and returning unabsorbed fluid to the holding tank. The main problem with this kind of tank is that it must be cleaned with a 0.5 to 1.0 % sodium hyperchlorite solution to stop the spread of mycological diseases. In the Nutrient Film Technique, a wooden tray is used instead of an inflexible PVC pipe and supports a plastic tube. The tube has holes in it at certain intervals and the plants are put in the tube where they are immersed in a nutrient solution.

The best method to extract the nutrients from a compost for use in a Nutrient Film Technique is that of the tea bag. The grower simply fills a sack with the compost and places it in warm water for about a week. The nutrients seep out of the bag into the water and the solids are left behind. These solids can be re-used for another group of plants, still containing organic materials needed for optimal growth. Compost tea must be changed weekly, as well as completely changing the nutrient solution, as failure to do so will create an over-nutrient situation.

Hydroponic Crops

New types of greenhouses are being designed to distribute sunlight during the day to promote better plant growth, and to retain heat at night thus saving on fuel. These kinds of greenhouses are rapidly being adopted as the industry standard and are increasing yields and decreasing plant loss, making this mode of crop production more profitable for the grower than soil-based methods. Specialty crops such as tomatoes, lettuce, cucumbers, and hot peppers, which cannot be grown conventionally all year long, are being grown hydroponically year ‘round. These vegetables that were previously scarce in winter are now plentiful. Since hydroponically grown vegetables can be continuously harvested, even regions that have harsh winters or short growing seasons can grow these specialty crops.

One fruit that used to be especially hard to find at certain times of the year is the strawberry, but times have changed over the last few years. The strawberry industry is beginning to convert from the traditional soil grown varieties to the hydroponically adapted ones. This dramatic change was brought about by an eminent ban on methyl bromide, which was used in the past to fumigate strawberry plants against fungal pathogens. If the plants were not treated, yields dropped, as these disease agents destroyed the leaves and roots of the plant, as well as the fruit itself.

We propose the following total daily intake of 739 kcal of these various vegetables and fruits. One serving equals 100 grams.

Bananas

The banana: the comedian's friend. For as long as there has been comedy, the old banana peel gag has been around. The average person consumes up to 27 pounds of bananas per year. That’s a lot of peels to try and avoid! The benefits of eating bananas are widely known. Containing three natural sugars - sucrose, fructose and glucose - combined with fiber, a banana gives an instant, sustained and substantial boost of energy. Research has shown that just two bananas provide enough energy for a strenuous 90-minute workout. No wonder the banana is the number one fruit among the world's leading athletes.

As we all know, the banana is one of nature's best sources of potassium. Potassium is known to significantly lower the risk of high blood pressure and related diseases like heart attack and strokes. It can also help overcome or prevent a substantial number of other illnesses and conditions such as anemia, constipation, heart burn and weight control. Many reports have concluded that to avoid panic-induced food cravings, we need to control our blood sugar levels by snacking on high carbohydrate foods every two hours to keep levels steady. Bananas are an excellent choice for that purpose. Banana trees are one of the more popular plants to use in conjunction with black water as they do extremely well under hydroponic conditions.

Growth

Bananas have been grown in soil consisting of 50/50 coconut fiber and Perlite. A temperature between 27 to 30 degrees C is ideal. The roots are immersed in a water/ liquid fertilizer solution and the plant is supported by wires. Fertilizers should contain N-P-K at a ratio of 3-1-6. The ratio is doubled when fertilizers are applied to young plants.

Parent plants produce large bunches of bananas and many are lost from pseudostem snaps and uprooting, so a plant spacing of 3 x 1 m with one follower, not the standard 3 m x 3 m with 3 followers, as used by the industry, is indicated. Do not apply fertilizers to tissue cultured plants until they are established and growing strongly. This is likely to be achieved in one to two months after planting. The young plants should be kept moist all times, as the young plants do not have well developed root systems and are sensitive to water stress. They can be established using a drip or under tree irrigation system. Irrigation can be scheduled using tensiometers.

Cavendish

Reaches five to ten feet high; fruit is bigger than Bungulan; peel is green when unripe, yellow when ripe; flesh is yellow when ripe; export quality; gestation period is six to eight months. (shorter than all other types that take at least 12-15 months to ripen).

Additional Nutrition Facts

Calcium: 6mg	Iron: 0.31dmg	Niacin: 0.54mg
Potassium: 396mg	Riboflavin: 0.1mg	Sodium: 1.0mg
Thiamin: 0.045mg	Vitamin A (I.U.): 81	Vitamin C: 9.1mg

Other Uses of Bananas

Banana waste can be used to make paper - 300X stronger than pulp paper.

Carrots

Nutritional Facts

Carrots are rich in ß-carotene, a substance that is converted to Vitamin A after ingestion. A 1/2 cup serving of cooked carrots contains four times the recommended daily intake of Vitamin A in the form of protective ß-carotene.

Beta carotene is also a powerful antioxidant effective in fighting against some forms of cancer, especially lung cancer. Current research suggests that it may also protect against stroke, and heart disease. Research also shows that the beta carotene in vegetables supplies this protection, not vitamin supplements. So eat your carrots.

Varieties include Nantes Half-long, Danvers Half-long, Pioneer and Spartan Bonus. Gourmet varieties such as Little Finger are also excellent in container gardens. Below are some varieties and their characteristics.

Growth

Carrots are a hardy, cool-season biennial. Although carrots can endure summer heat in many areas; they grow best when planted in early spring. The best temperature for highest quality roots is between 60 and 70 degrees F. Carrots do not grow well in strongly acid soils. Therefore, a pH range of 6.0 to 6.8 should be maintained for best results. This information is valid both for soil and for hydroponics.

Suggested planting depth is 1/4 inch deep in rows spaced 12 to 18 inches or more apart depending on the method of cultivation used. After the seedlings have emerged, thin them to one inch apart. When the tops of the carrots grow thicker, thin them to about two to three inches apart

Additional Nutrition Facts

Calories: 35	Phosphorus: 23.4 mg
Calcium: 24.18 mg	Vitamin A: 19,152 IU
Iron: 0.47 mg	Vitamin C: 1.79
*** (1/2 cup cooked=168gms)

Cucumbers

Cucumbers originated in India in a region lying between the Bay of Bengal and the Himalayas. They have been continuously cultivated for over 3,000 years and are one of the oldest domesticated plant species.  The cucumber was mentioned in the Bible, being grown in North Africa, Italy, Greece, Asia Minor, and other areas at the beginning of the Christian era.  In England the crop was first introduced in the 1300s, but not cultivated until 250 years later.  Columbus planted seeds in Haiti, and by 1539 cucumbers were grown in Florida by the natives, reaching Virginia by 1584.

Today cucumbers are grown all over the world for pickling (picklers) and fresh markets (slicers).  Cucumbers grown in greenhouses have traditionally been grown near cities, mostly in the northeastern United States.  Cucumis sativus is a common slicing and pickling cucumber.  They are the same species, but used differently, yet the flavor and texture are very similar. Cucumis anguria are the Gherkin type that originated from West India.

Growth

The transplanting process efficiently uses greenhouse space because seed germination and early growth can be confined to a smaller area.  Transplants should be grown in structures separate from those used for fruit production. This allows temperature control to be confined to a smaller area and will be more conducive to good sanitation practices ensuring disease-free plants.  Temperature should be maintained at a constant 85 degrees Fahrenheit to accelerate germination.

Cucumber plants can be grown in 3 by 4 inch pots or in 2”x 2” solid containers and should be placed next to each other.  After seeding, any spaces left between containers can be filled with vermiculite to prevent the container walls from drying between watering.  Plants are ready for transplanting into the greenhouse in 2 to 3 weeks, depending upon temperatures and light conditions.

The decision of the number of plants to be grown in a given area should be based on the light conditions during the growth of the crop and also on the method of pruning the plants.  When full sunlight is expected almost every day--as from mid-spring through the late fall--more plants can be accommodated under low light. With good sunlight, each plant is allotted about 5 square feet of space. Twice as much space is needed in lower light conditions to avoid leaves overlapping and shading by nearby plants.  Spacing between rows and plants within the row can vary with grower preferences.  Rows are usually spaced 18 to 20 inches apart in the row for vertically cultivated plants.

Strings are attached to a tightly drawn horizontal wire centered on the row just above the top of the containers or the surface of a bed.  Support strings are attached a week after transplanting, when vertical growth begins.  As the plant grows, the main stem is loosely wound around the string for support.  Cucumbers should never be allowed to suffer from lack of water or nutrients. Greenhouse cucumbers grow fast under ideal environmental conditions and fruit production begins 60-70 days after seeding. Temperature range of 75-80 degrees is ideal. The tea bag method is preferred for the growth of greenhouse cucumbers.

There are three major cucumber cultivation types currently in production: processing (pickling), fresh market (slicing), and greenhouse (slicing). Cucumbers have become popular due to wide variety of fruit types.

Processors

These fruit are “warty” in appearance and light green in color.  Pickling cucumbers have either black or white spines on their skin. ‘Conquest’ (F1 hybrid) and ‘Littleleaf’ are two superior pickling cucumber cultivators that have been bred for disease tolerance.

Fresh Market

This variety is usually longer, smooth rather than “warty”, and have more uniform green skin color, and the skin is tougher than the pickler variety.  A few American slicing cultivators are ‘Jazzer’ (F1 hybrid), ‘Superset’ (F1), and ‘Marketmore’ (non-hybrid).  The ‘Fanfare’ hybrid and the ‘Tasty King’ hybrid, are common Southeastern cultivars from Park seed. ‘Lemon’ is a pale yellow round cucumber that grows well in the southeast.  It is a popular specialty salad item.

Greenhouse

British Columbia, Canada and the Pacific Northwest have been successful at growing different varieties of cucumbers in the greenhouses. Greenhouse growing in the southeast has a different environment and cultivars need to be chosen that would benefit from the local climate where they are being grown.  All cucumbers grown in the greenhouse are partheno-carpic, not requiring pollination.  They are gynoecious cultivations, which are all female.  The eastern European cucumbers are the best for salads, which can be grown in the greenhouse.  They are tender, yet crisp fruits that do not taste bitter nor need peeling.

Additional Nutrition Fact

Calories: 15	Sugars: 2.0 g
Cholesterol: 0%	Vitamin A: 4%
Sodium: 0 mg	Vitamin C: 10%
Calcium: 2%	Iron: 2%

Eggplant

Eggplant is considered a fruit, but botanically it’s actually a berry. Long prized for its deeply purple, glossy beauty as well as its unique taste and texture, eggplants are now available in markets throughout the year.

Eggplant substances, called glycoalkaloids, are made into a topical medicated cream used to treat skin cancers such as basal cell carcinoma, according to Australian researchers. Also, eating eggplant may lower blood cholesterol and help counteract some detrimental blood effects of fatty foods. In addition, eggplants have antibacterial and diuretic properties. Besides featuring a host of vitamins and minerals, eggplant also contains important phytonutrients, many of which have antioxidant activity. Niacin is a potent antioxidant present in this plant that has been found by many researchers to protect the lipids of brain cell membranes, hence eggplant is often called the “Brain Food”. The antioxidant property of Niacin also prevents cellular damage in cancer, lessens the free radical damage in joints, in rheumatoid arthritis and protects blood cholesterol from peroxidation, thereby enhancing cardiovascular health.

Growth

Eggplant needs warmth throughout the growing season to do well, soil temperatures above 70°, and daytime air temperatures above 70°. Nighttime temperatures should be above 60°. Eggplant has a growing season of 100-150 days under ideal conditions. Although they do best in warm climates, they can be grown in northern climates if mulches, row covers, or hot houses are used.

They require a pH 5.5 to 6.5 with high organic matter content. Eggplants need a moderate amount of nitrogen and high amounts of phosphorus and potassium. Eggplants like temperatures between 80° and 90° for optimal growth. Eggplants are typically spaced 18-24" apart in rows 30-36" wide. Rows should be 30-36" apart. Their growing season is 100-150 days in ideal conditions in soil.

Additional Nutrition Fact

Calories: 27.7	Potassium 245.52 mg
Phosphorus: 21.78 mg	Folate: 14.26 mcg

 

Green Beans

Green beans originated in Central America more than 5000 years ago and are now one of the most popular vegetables consumed, world-wide. Beans are collectively known as legumes and there are more than 1200 varieties of them. Green beans were brought to Europe by the Spanish and Portuguese. String beans are the oldest variety of bean. In fact, most commonly cultivated beans (Phaseolus) have a New World heritage. The origin of this hardy plant lies somewhere near Guatemala, and its migration throughout North and South America had occurred long before Europeans arrived. Beans were almost as universally cultivated as maize by the native people. Green beans and other related types, such as, kidney beans, navy beans and black beans derive from a common ancestor. They were all introduced into Europe around the 16 th century by Spanish explorers. The term "string bean" refers to the lignified vascular bundle that develops in certain cultivars of pole beans.  Plant breeders in the 1950s used them as a starting point to develop bush-type (determinate) beans with vascular bundles that did not become stringy until the beans were mature. These new varieties are called "snap beans" to differentiate them from the parent strain of bean. Today, the largest commercial producers of fresh green beans include the United States, China, Japan, Spain, Italy and France.

Green beans are low in calories and are an excellent source fiber. In addition, they contain high amounts of vitamins K and A due to the presence of carotenoids, including ß-carotene. Green beans are also an excellent source of vitamin C, riboflavin, potassium, iron, manganese, folate, magnesium and thiamin. Finally, they contain nutritionally significant amounts of manganese, phosphorus, calcium, niacin, vitamin B6, copper, protein, and zinc to a lesser extent.

Growth

Humic and fulvic acids added to any nutrient mix increases the rate of development and length of root systems and accelerates cell division. These acids also increase foliage and bean yield. Minerals such as silica, nickel, cobalt and selenium are apparently not essential for plant growth in soil-based farming situations. However, they do enhance growth and development in soil-less systems. Humic and humic-derived acids occur widely in mineral soils, peats, and some natural waters. These organically derived acids are water-soluble and are produced during the microbially-assisted decomposition process of plant material.

Many trace elements that are essential nutrients for all plants are not soluble at optimal pH ranges for optimal growth when employed in hydroponic systems. Therefore, most trace elements, such as iron, area supplied in a chelated form using a synthetic chelation agent such as EDTA. Humic acids also can serve as chelation agents; they are chemically strong enough to protect the micronutrient but weak enough to release the micro element to the plant when required.

Green beans grow at a pH of 7.6, and at an average ambient temperature between 65-75 degrees F. As is true for most plants, the three most important macronutrients are nitrogen, phosphorus, and potassium. Nitrogen is added to help the above ground plants mature rapidly and produce dark green foliage. Phosphorus is essential to help develop strong roots, fruit, flower development, and resistance to many plant pathogens. Potassium protects the plant from cold and dry weather, and excessive water loss. For seedlings, the nutrient level should be 400 to 600 ppm; for vegetative growth 800 to 1100 ppm; for blooms 1000 to 1400 ppm.

Additional Nutrition Facts

The amount of vitamin K in one cup of green beans supplies 155% of the daily-recommended value. They are an excellent source of vitamin A from their ß-carotene content. Vitamins A and C in green beans are important anti-oxidants that help reduce free radicals in the body. Magnesium and potassium work together to help lower blood pressure; folate and vitamin B6 are needed to convert homocysteine into more benign molecules. For atherosclerosis and diabetic heart disease, few foods compare in value to green beans. Beta-carotene and vitamin C have strong anti-inflammatory effects. This may make green beans helpful for reducing the severity of conditions such as asthma, osteoarthritis, and rheumatoid arthritis.

Green beans have almost twice as much iron as spinach. Iron is an integral component of hemoglobin. Copper and manganese are essential cofactors of the oxidative enzyme, superoxide dismutase, that neutralize free radicals produced in the mitochondria. Copper is necessary for the activity of lysyl oxidase, an enzyme involved in cross-linking collagen and elastin. Zinc is essential for a fully active immune system. Green beans are also a good source of thiamin, a vitamin essential for synthesizing the neurotransmitter acetylcholine.

One serving of 83g contains:

Lettuce

Lettuce gets its name from the Latin root words referring to its milky juice. Lettuce is a member of the sunflower family. Watercress was carried by Greek, Roman, and Persian soldiers during their campaigns and eaten specifically for its property (high vitamin C content) of preventing scurvy. Iceberg lettuce was originally known as Crisphead until the 1920s. California began transporting large quantities of lettuce underneath mounds of ice to keep them cool, which resulted in its new name, Iceberg. In Europe, Romaine lettuce is called cos, after the Greek island of Kos in the Aegean Sea. Lettuce is the most important of the leafy crops grown in the U.S. The plant is an annual, grown from the seed, and reaches harvest size from 45-90 days, dependent upon the climate. The three main varieties of lettuce are heading, cutting or leaf, and Cos or Romaine. An average head of lettuce weighs from 7-9 ounces and can reach up to12 ounces or more under ideal conditions.

Growth

Lettuce is best grown with the nutrient flow technique, which does not encourage the spread fungal diseases. Lettuce seeds are planted at 9-inch distances in growing channels. These are placed next to each other in the first section at 3.5 inch distances. When the space fills with plants after two weeks, these channels are moved to the second section where the outlets are 4.5 inches apart. After another two weeks, the first batch of plants is moved to the third section where outlets are 6 inches apart. This procedure is repeated for 7.5 inches. This method increases the plant output by 35%. Eight to ten crops per year can be grown in this manner. In this particular case, the advantages of hydroponic cultivation become quite obvious. Generally, the spacing depends on the size of the plants at maturity. If they have a width of 6-8 inches the seeds should be spaced 8 or more inches apart. Roots require six inches of depth in order for a lettuce plant to grow to maturity.

Additional Nutrition Facts

Romaine lettuce: Darker green lettuce leaves are more nutritious than lighter ones. Light, crispy lettuce is the second most popular fresh vegetable, according to food experts.

Serving Size (1/2 cup, shredded raw)

Peppers

Sweet peppers, such as green peppers, originated in South America from a wild variety dating back 5000 years. They were traded throughout the world by Spanish and Portuguese explorers. Bell peppers, also known as sweet peppers, are the “Christmas ornaments” of the vegetable world, since they are beautifully shaped, glossy in appearance, and come in a variety of vivid colors - green, red, yellow, orange, purple, brown, and black. Yet, despite their varied palette, all are essentially the same plant, Capsicum annuum, and are members of the nightshade family, that also includes potatoes, tomatoes, and eggplant. Green peppers were chosen because they are high in Vitamin C, bioflavinoids and ß-carotene. Peppers are rich in capsaicin that may help fight inflammation. They have powerful antioxidant properties.

Growth

Peppers need 8-10 hours of sunlight a day. Temperatures are best at between 70-80 degrees F during the day, and 60-70 degrees at night. Peppers require sixteen nutrients for optimal plant growth. Primary macronutrients include nitrogen, phosphorus, and potassium. Secondary macronutrients are calcium, magnesium, and sulfur. Micronutrients include iron, manganese, boron, molybdenum, zinc, copper, and chlorine.

Additional Nutritional Facts

Peppers contain antioxidants that work together to effectively neutralize free radicals. Thus, bell peppers may help prevent or reduce some of the symptoms of the build up of cholesterol in the arteries that leads to atherosclerosis and heart disease, nerve and blood vessel damage seen in diabetes, and cataracts. Consuming foods rich in ß-cryptoxanthin, a carotenoid found in red bell peppers may significantly lower one’s risk of developing lung cancer.

One medium green pepper (148g) contains:

Soybeans

In recent years soybeans have increased in popularity because of their high nutritional value and versatility. Soybeans are a rich source of Vitamin A and also provide a significant amount of carbohydrates, iron, and most importantly protein. Soybeans are a staple food in many parts of the world because of their high protein content. Strict vegetarians often rely on them as their sole source of protein. Infants who are lactose intolerant can tolerate formulae made, in part, from soybeans. The soybean plant is hearty and grows easily indoors or outdoors. Soybeans also grow more efficiently when grown hydroponically as compared to soil-based farming.

Growth

The Hoyt variety of soybean is a good one for production in the vertical farm since it matures rapidly and gives very high yields of fruit. Hoyt’s relatively small size makes it ideal to grow in the International Space Station, as well as in other places where area and space are severely restricted. It takes 24 days to produce flowers and 80 days to harvest, during which time they grow to a maximum height of 20-30 centimeters. Soybeans grow well at a pH of 6.0-6.5. Plants require an average daily temperature of 27 degrees C to flower, and 22 degrees C prior to flowering. The Hoyt soybean strain is a “short-day” variety that must have 12 hours of complete darkness every night.

Additional Nutrition Facts

One serving soybeans = 1/2 cup = 75 g contains:

100 calories	3 g fat (4% daily value)	9 g carbs (3%daily value)
4g fiber (14% daily value)	8g protein	9% Vitamin A
9% Vitamin C	5% Calcium	9% Iron

 

Spinach

Arab traders introduced spinach into India, and then into China in 647 A.D., and, with the Moorish advances, into Spain and southern Europe. Some agronomist/historians believe that spinach was being grown in Spain as early as the 8th century. The record is clear that it was in the diets of those living on the Iberian peninsula in A.D. 1100. By the 1300’s, spinach cultivation had spread to Britain, where it was popular with religious communities, particularly during Lent.

In 1533, Catherine de'Medici became queen of France, and she so fancied spinach that she insisted it be served at every meal (a Popeye ancestor?). Because spinach was suspected to have curative powers with regards to iron deficiencies, wine fortified with the soluble part of the plant was used to treat French soldiers weakened by hemorrhage. To this day, dishes made with spinach designated as "Florentine" on the menu because Catherine came from Florence. Spinach is another leafy green whose nutritional reputation lies in its high oxalic acid content. Most of us need not pay attention to this property of spinach, but those with kidney disease, especially kidney stones, rheumatoid arthritis, and gout should be aware and not over-consume in this category of produce. In large quantity, oxalic acid is considered a potent poison. Fortunately, the only place in nature where oxalic acid occurs at near toxic levels is in rhubarb leaves. That is why it is recommended that only the stalks be eaten.

Growth

Spinach grows best at pH 6.5-6.9, and at an average day-time temperature of 70-80 degrees F. Essential macronutrients are nitrogen, phosphorus and potassium. The growth requirements for each spinach variety is similar to those given for lettuce. Spinach plants require 8 hours of light/day.

Additional Nutritional Facts

Spinach contains lutein that may help reduce macular degeneration. It is also rich in folate and is an excellent source of carotenoids, iron, vitamin K, oxalic acid, and vitamin C.

1.5 cups of spinach (86g) contains:

Calories: 40	Calcium: 6%	Cholesterol: 0%
Iron: 20%	Sodium: 160mg	Sugars: 5g
Vitamin A: 70%	Vitamin C: 25%

Strawberries

Strawberries are well known for their high nutritional value. They have more Vitamin C than citrus fruit when compared ounce for ounce. According to the American Cancer Society, foods rich in Vitamin C might lower the risk of gastrointestinal cancer. Strawberries are also high in folic acid or folate, a water-soluble B vitamin that helps prevent birth defects such as spinabifida. Eight strawberries per day will provide more than 20% of the daily-recommended folate intake for expectant mothers. Strawberries are also one of the richest fruit sources of antioxidants, and they are high in dietary fiber. Strawberries are low in calories.

Growth

Hydroponic cultivation has become widespread as a result of the availability of a wide variety of efficient systems that result in high yields. Hydroponics makes it easy to maintain ideal water and nutrient levels for production of robust, undamaged fruit. This technology also allows the crop to be grown without employing methyl bromide, which traditional strawberry cultivators worldwide still use to control fungal pathogens. There are many varieties of strawberries as well as many varieties within each class of strawberry. The classes include everbearer, Junebearer, day neutral and short day varieties. Flowering cycles of all varieties of strawberries are affected by day length, hence each variety is aptly named.

Temperature significantly influences strawberry growth and can override day length as the controlling factor for flowering. When temperatures drop too low it results in poor flower and fruit formation; however, high temperatures will cause strawberry plants to wilt and stop producing flowers and fruit altogether.

Several hydroponic gardening methods are in common use today. The ebb and flow or flood and drain method is efficient for growing large numbers of plants. Smaller, multi-tiered, deep-water culture, NFT (Nutrient Film Technique), or drip irrigation are preferred methods for both hobby and smaller commercial growers.

Additional Nutrition Facts

One serving strawberries = 1/2cup = 83 g

Calories 25	Protein .5 g	Carbohydrates 5.825 g
Dietary Fiber 1.905 g	Calcium 11.62 mg	Iron 0.315 mg
Magnesium 8.3 mg	Phosphorus 15.77 mg	Potassium 22.41 mg
Selenium 0.58 mg	Vitamin C 47.06 mg	Folate 14.69 mcg
Vitamin A 22 IU