5.1 Examples of Human Food or Animal Feed from Hydroponic Crops

That said, in hydroponic systems, a plant’s nutrient levels can be enhanced simply by adding nutrients to the solution. These nutrients could include calcium and magnesium, or microelements such as zinc or iron. Conversely, soil-based systems are relatively inefficient because of nutrient leaching and evaporation, thereby requiring more inputs than hydroponic systems, which can more precisely control the crops’ growing environments. As a result, hydroponic systems lead to greater yields, reduced water and nutrient losses, and a greater uniformity of produce.

Different Types of Produce

Many high-input and short-duration crops are grown in hydroponic systems (Wootton-Beard 2019).In principle, it is possible to grow any crop using hydroponics, provided the plant can access enough water and nutrients to support its growth. Hydroponic systems grow many high-input crops such as peppers, tomatoes, strawberries, and cucumbers (Wootton-Beard 2019). The use of hydroponics to grow flowers and other nonvegetable, high-value crops has increased in recent years (Jones 2016). Short-duration crops, which are crops that reach maturity in a short period of time but are sensitive to changes in environmental conditions, are well-suited for hydroponics. These crops include leafy greens, annual herbs, and salad leaves (Wootton-Beard 2019). Short-duration crops require protection from pests and disease and carefully controlled irrigation to maintain leaf quality. Hydroponic systems do this and, in the case of leafy crops, keep them free from soil contaminants (Wootton-Beard 2019). Table 5.1 presents a list of examples of crops grown in hydroponic systems. All these crops tend to be profitable enough to justify a hydroponic operation (Jensen 1999).

TABLE 5.1 Examples of Human Food or Animal Feed from

Hydroponic Crops

Vegetables Fruits Herbs Grains/ animal fodder Flowers

leafy greens, radishes, celery, cucumbers, potatoes, yams, peppers, wheatgrass, onions, leeks, carrots, parsnips, squash, zucchini, corn, bok choy, kale, swiss chard, arugula, watercress, chives, broccoli, beans, squash, peas, cauliflower, cabbage, carrots, onions, radishes, beets, microgreens, melon tomatoes, watermelon, cantaloupe, strawberries, blackberries, raspberries, blueberries, grapes, dwarf citrus trees (lemons, limes, oranges), dwarf pomegranate tree, bananas Chives, oregano, mint, basil, sage, rosemary barley, oats, wheat, sorghum, alfalfa, cowpea, maize, rice roses, peace lilies, hoya, snapdragons, dahlias, carnations, orchids, petunias

Source: Original table for this publication.

Animal Fodder

Hydroponic produce can help meet the world’s need for green fodder for livestock. Fodder crops produced by hydroponics are also known as hydroponic fodder, sprouted fodder, or sprouted grain. These crops include oats, wheat, maize, barley, sorghum, cowpea, and alfalfa. The expansion of global livestock populations has significantly increased the world’s demand for green animal fodder (Government of India 2010; Brithal and Jha 2010). At the same time, the world’s land allocation for green fodder cultivation is limited (Dikshit and Brithal 2010). Hydroponic green fodder is produced from forage grains, such as malt barley or oats, has a high germination rate, and generally takes only seven days to grow (Sneath and McIntosh 2003). Since fodder sprouts are young and tender, they are similar to fresh green grass. They are also high in protein and comprise metabolizable energy; thus, they are highly palatable, highly nutritious, and disease-free.

The hydroponic process to produce green animal fodder is specific. It takes place in an intensive hydroponic growing unit where water and nutrients are used to produce a lush and nutrient-rich grass and root combination. Some systems use tunnels or greenhouses to provide a level of climate control. In greenhouses, water fogging and tube lights automatically maintain light, temperature, and water and humidity levels (Chandra and Gupta 2003). Depending on the type of grain or grass being grown, the forage mats are 15 to 20 centimeters high and produce about 7 to 9 kg of fresh forage, which is equivalent to 0.9 to 1.1 kg of dry matter (Mukhopad 1994; Bustos et al. 2000). The fodder yields are also determined by the seed rate. Most commercial hydroponic units recommend a seed rate of 6 to 8 kg/m2 (Morgan, Hunter, and O’Haire 1992) for higher outputs (Naik and Singh 2013). Each seed then produces a 200- to 250-millimeterlong vegetative green shoot with interwoven roots in five to eight days. If seed density is high, there is a greater chance of microbial infection in the root mat, which can affect sprout growth.

Green fodder grown from hydroponic systems has various benefits. In the harsh climate in Lodwar town in Kenya, women grew hydroponic barley for feed for smaller livestock, mainly goats. They grew the barley in metal trays with nutrient solution. It took seven days to convert 2 kg of seeds into 12.5 kg of fodder for 10 goats. The goats that consumed the hydroponically grown barley had increased milk yields during the dry season (WFP Kenya 2020). In Chad, more than 230 hydroponic units enabled communities to produce 340 tons of hydroponically grown animal feed in 2020 (Gabe 2020). This was particularly helpful when local feed markets were closed or unsafe. White sorghum is another option for hydroponic animal feed. Various studies estimate that feeding hydroponic fodder to lactating cows increases milk yields by 8 percent (Reddy, Reddy, and Reddy 1988) to 14 percent (Naik and Singh 2013). Farmers in India’s Satara district in Maharashtra said that milk production increased by 0.5 to 2.5 liters per animal per day, increasing net profits by 25–50 rupees

per animal per day. In addition, cows fed hydroponic fodder had sweeter and whiter milk with increased fat content, improved health and conception rates, and reduced cattle feed requirements by 25 percent. The farmers also said growing the fodder had reduced the cost of labor and required less land than fodder grown on soils (Naik and Singh 2013).

Examples of Animal Fodder Production in West Bank and Gaza

West Bank and Gaza provides an example of successful hydroponic green fodder production. For US$800, farmers in West Bank and Gaza can purchase a hydroponic system optimized for green fodder production. This self-contained system measures 75 × 100 × 180 centimeters and is equipped with seven layers of two growing trays per layer (see photo 5.3). The system is designed to feed goats and sheep on small farms. Two of the 14 trays provide approximately 18 kg of green fodder—enough to feed 7 to 10 sheep or goats each day. The system can maintain this feeding rate for the entire year. The initial investment to establish the system is high for local conditions, but farmers expect to break even within the first year. Moreover, farmers claim that milk production increased by 40 to 50 percent since they implemented their hydroponic fodder systems.3 Table 5.2 shows the financial breakdown of the system’s investment costs.

PHOTO 5.3 Two Views of a Hydroponic Green Fodder System in

West Bank and Gaza

Photographs © Applied Research Institute–Jerusalem. Used with permission from Applied Research Institute–Jerusalem. Further permission is required for reuse.