Crop Production Feeding time k r a P

l a t at the n e m n o r i v n E

o o Z A zoo may not seem the obvious place for horticultural n o t n g i a innovation. Kevin Frediani knows otherwise. He reports P

: s o t o h on a new growing system that may have wider P A Sulawesi Crested Black Macaque, a member of a implications for urban crop production. threatened species of primates, whose world conservation programme is co-ordinated at Paignton Zoo Environmental Park, benefits from the enrichment that the new system provides in mixed salad leaves.

aignton Zoo Environmental Park is not reviewed and its focus is to optimise the the first place that would come to potential for plants to support and underline Pmind, if you were thinking of the zoo’s mission of education, research and horticultural innovation. Until recently, conservation of the world’s animals, plants horticulturists outside of were mostly and their habitats. The result is a new unaware of how integral plants have botanical direction and an integrated become within the landscapes of modern approach to zoo horticulture (Frediani, zoos. Nor would they necessarily be aware 2009a & b). of the development of specialist displays or Many of the plant-use themes highlighted ‘immersive exhibitory’, where the visitor in the Integrated Zoo Horticulture table (see shares the same landscape but not the same Figure 1), are relatively easy to understand space as the animals they have come to see and also to achieve. A few required a bit (Owen, 2008, Miles, 2009). more exploration and innovation to achieve. The term - immersive exhibitory - was first Food production would involve land being coined by Landscape Architects, Jones and taken away from exhibits. Enrichment first Jones Landscape when working on the first had to be defined in terms of the use of of the new generation of zoos in America landscape and plants in order to encourage (Seattle Zoo Master plan1976). It is a term natural behaviour in animals (Frediani, Kevin Frediani is Curator of Plants and not yet in wide use, but now that more 2009c); while ‘sustainability’ as a concept Gardens at Paignton Zoo Environmental immersive exhibits are being designed and proved difficult to interpret in terms of Park. executed in most of the top European and tangible developments for visitors to see and UK zoos, it may become more familiar. enjoy. He trained in horticulture and plant science Existing examples include the squirrel at Nottingham University. His varied career monkey, gorilla settings and the walk- includes training in the curation of living through bird aviary at . Sustainable project collections at Cambridge University Paignton Zoo opened to the public in 1923 In August 2008 the zoo hosted a Botanic Garden and teaching the care and following 20 years of development as a sustainability event to showcase the work of management of trees and their landscapes, environmental businesses working in the while at the Scottish Agricultural College private collection by its benefactor Herbert (SAC). At SAC he became a national Whitley. The zoo has always had a large southwest to its visitors as part of a green examiner for the care of trees and helped botanic collection which today numbers solutions festival. A Cornish company, write the new British Standard for Tree around 5,000 plant accessions. Currently Valcent (EU) Ltd, which was beginning to Care (BS3998: 2008). 2,500 species are represented on the 30ha promote a new vertical growing technology site in . to grow fresh leaf crops on a conveyor Later he worked at Windsor Great Park, The garden’s collection has recently been system attended the festival. Although not where, as Assistant Superintendant of yet fully developed to grow crops, a pilot Parks in charge of the private Royal project had already been realised to grow Gardens and Grounds, he also was algae crops as a biofuel in El Paso, Texas. charged with the care of 3,250ha of internationally important parkland The company was planning a new pilot landscape. He was the first Curator of project to adapt this technology to grow Plants at the Zoological Society of London fresh leaf crops in . The system, where he developed a new department VertiCcrop™, had funding but no place had intended to transform the garden yet been defined for it to be built. landscape at London Zoo and Whipsnade Four months into the post as curator of Wild Animal Park. He recently returned plants and gardens, I presented a vision for from working abroad as Hortulanus at De the gardens based around this new Hortus Botanicus in Amsterdam. sustainable technology. The aim was to show in the public area of the zoo an exhibit He has been in post at Paignton since June 2008 and recently completed his post- that produced food for the zoo’s animals to offset food bills, increase food security, and graduate degree in conservation and Figure 1 environmental management at Surrey Eight plant-use themes that define the breadth of facilitate research and development. This University. zoo horticulture (after Frediani, 2009). latter aim would lead to the improvement

12 THE HORTICULTURIST APRIL 2010 The VertiCrop™ at Paignton Zoo showing the vertical growing system.

THE HORTICULTURIST APRIL 2010 13 and development of the diets of captive animals. A project followed, which some ten months later opened as the first Vertical Farm in a zoo or botanic garden, using this growing system to produce crops for the zoo’s animals (Bouquet, 2010). How does it work? The system comprises 3m high, multilevel growing trays, which are suspended from an overhead track. Each `rig’ consists of eight levels of growing channels or `trays’ of which there are two different sizes to accommodate different crops. Each growing tray has been purpose-built for the system and a number of different crops can be grown simultaneously.Trays are adjustable for depth of buffer solutions and the nutrient levels can be modulated as the nutrient solution is delivered through a funnel, the nutrients being time-dosed at the feeding station. “Using this system the The original model of the VertiCrop system, first shown to the author at the Green Solution Festival in August 120sq.m greenhouse 2008. Chris Bradford (left), Managing Director of Valcent (EU) with Kevin Frediani. grows three times the control system provides plants with the space required to grow the same amount of 3,000 plants that would optimal growing environment, while also crop, thereby reducing the investment in be expected integrating the advanced hydroponic land that would normally be required to technology that automatically supplies water support the project. The conveyer movement on a conventional and nutrients at the central feeding station. ensures even light and air distribution. It The run-off solutions are captured and also allows for centralised locations for hydroponic system ” recycled through the whole irrigation irrigation, and the loading and unloading of system. This enables a saving on water and crops. The result is an increase in growing Advanced hydroponic technologies make it nutrient-use and avoids the pollution area available since the space needed for possible for a total of 70 custom-made rigs, associated with field-grown crops. access is reduced, which offers a number of holding 16 growing trays suspended on a The use of vertical space reduces the floor benefits, including reduction of the risk of closed loop conveyor to grow 11,200 plants. introducing pest and diseases (see Figure 2). The plants are maintained in constant The zoo’s pilot has been installed and is motion around the greenhouse track with fully operational. At each level, specially each circuit taking approximately 40 minutes designed trays carry various micro-greens, to optimise the exposure to light, and lettuce and salad mixes, that have been support gaseous exchange. Using this planted sequentially to provide a regular system the 120sq m greenhouse grows three supply of fresh green leaves. The primary times the 3,000 plants that would be focus is economic profitability, improved expected on a conventional hydroponic nutritional value and environmental system (Bayley, J. et al 2010). enrichment to enhance the lives of captive A computerised Priva environmental Figure 2. VertiCrop increases yield per unit area animals in the zoo. (after Bayley, 2010).

Figure 3. Example of how space can be saved by using this innovative system compared with Figure 4. Comparison of the area required to grow lettuce plants in the conventional horizontal hydroponic systems. Note that the total footprint includes a 15% field, a conventional hydroponic system and via the 3m high Paignton Zoo service area (After Bayley, 2010). or 6m high optimised VertiCrop system.

14 THE HORTICULTURIST APRIL 2010 The future Food sense The technological advances of the system allow for the efficient use of precious The annual bill for animal feed at Paignton is currently in excess of £200,000, so the resources such as water and land offer. A spotlight is on the high-intensity VertiCrop system to produce ultra-fresh produce onsite, system such as this has applications that and also to reduce both food miles and food costs for the zoo. could be important to solve problems in the The vegetables, herbs and other produce grown on site are harvested and fed out wider world, for example, in urban immediately, guaranteeing the animals have the freshest produce currently available. Zoo environments and areas with extreme staff and researchers are looking to use the system to not only enrich the lives of the climates or land degradation. Traditional animals with fresh produce, but also to manipulate the nutritional quality of the vegetables food production is competing for its land being grown using this system. In hydroponics and protected growing environments, there and water resources with an increasing is much more control of plant nutrition than there is in soil-grown crops. Starting with a number of emerging alternative uses, base of good quality water, the nutrient solution can be manipulated to influence the including biofuel and fibre production. Land compositional quality of the hydroponic crop. Whether this is for animals or for improving managers are also under pressure to adapt human nutrition, it is an idea that appeals to many. and contribute to the mitigation of climate change through less intensive use of the soil. Paignton Zoo is particularly interested in the nutritional quality of fresh fodder and is The Verticrop system offers an integrated hoping that the food produced with this system can be used to address problems such as hydroponic approach to address this central `hemosiderosis’ in zoo animals. Hemosiderosis is a world-wide problem in zoos where issue, using the most advanced technology certain animals, no longer dining on the food of their native habitats, consume too much to ensure efficient use of resources in crop iron which is stored in body tissues. This iron builds up in organs such as the liver where it production. stays permanently and causes severe tissue damage over time. While zoo animals can be The use of this technology makes it fed commercial pre-mixes low in iron, the fresh fruits and vegetables fed to many animals possible to bring commercial agriculture into as part or all of their diet typically contain more iron than is needed. Fruit, vegetables and the urban environment as part of an herbs are not only important in the diet of captive animals, but they are also important in integrated approach to provided food enrichment and activity programmes for animals, so the issue of iron levels and security. A 6m high system requires 87% less hemosiderosis can become widespread in some species. land and building footprint than This problem is further compounded at Paignton zoo as vegetables grown locally in the conventional hydroponic systems to grow deep red, iron rich soils of Devon are higher than normal in iron. In general, commercially the same amount of plants (see Figures 3 grown vegetables world-wide produced with soil fertiliser additions would be expected to and 4). Typically this represents projected have higher iron content than the vegetation many zoo animals would consume in their savings in excess of 40% on building and native environments. associated costs (Bayley, 2010). Combined Hydroponic systems use reverse osmosis, distilled or rain water (free from naturally with the latest lighting technologies, such as occurring iron in the water supply), so it is relatively simply to lower iron in the solution to LED, it opens the way for the warehouse levels where plant iron deficiency and growth reductions are limited. The resulting tissue culture of crops to protect the crop. has minimal iron levels, making it more suitable to animals prone to developing Redundant buildings in city centres could be hemosiderosis. Further manipulations of the nutrient solution and environment could see brought back into use, with suitable improvements in dry weight, fibre, vitamin and beneficial nutrient levels, phyto nutrients, environmental controls being established chlorophyll and other health-related factors in the fresh greens which are difficult or and maintained. impossible to achieve with commercially-prepared dried animal feeds.

sustainable way to achieve an important References k r social responsibility. a P l a t Bayley J. (2010). VertiCrop yield and n e m n environmental data. Valcent (EU) Ltd. o r i Urban crop production v n Launceston. Cornwall. E o

o Beyond the zoo, well that is a question! Z

n Bayley J, Frediani K & Yu M. (2010). o t Alongside traditional crop production in n g i Sustainable food production for the 21st a P

rural areas there is now a very real : o t century -VertiCrop™ High Density Vertical o h opportunity to look at urban crop production P Growing . ISHS in press. Fresher than fresh: just 15 minutes after harvest on a commercial scale. In an urban freshly cut leaves are offered to one of the zoo’s Bouquet T. (2010). Welcome to the 21st- elephants. environment the system can provide healthy food close to the market place, reducing Century of work – the vertical farmer. The packaging and transportation costs, relieving Times Magazine . 09.01.2010 pp37. Through the pilot project, the original brief the burden on infrastructure and saving Frediani K. (2009a). The ethical use of plants - to educate visitors to the zoo about energy. It also has the potential to be in zoos: informing selection choices, uses sustainable (horticultural) technology, to situated on land that may be unsuitable for and management strategies. International provide food and plant-based enrichment for other purposes or at present not utilised, Zoo Yearbook. 43: 29-52. the zoo’s animals and facilitate plant-based such as roof tops, basements, or disused research - has been achieved. Frediani K. (2009b). The Amsterdam Hortus – industrial sites. At the zoo, novel nutritional research is developing collection themes in established With so much potential it is surely a matter being conducted to find how to improve collections. Sibbaldia No 7. 1-8. of time before we see more investment in animal nutritional requirements using this vertical growing technology and wider Frediani K. (2009c). Exploring the potential system (see panel above). Eventually, it will acceptance of hydroponic culture by the for plant-based enrichment. Proceedings of be possible to extend the research direction public in our cities. While government the 9th International Conference of to include vertical cultivation of food, biofuel leaders are looking at new strategies for Environmental Enrichment. ICEE 2009 . and medicinal crops, such as high-value food security and energy conservation, the Miles T. (2009). Zoo Horticulture. James pharmaceutical products. system used at Paignton seems to provide Bruce Lecture 2009. The Horticulturist Winter There is potential for expanding the system the first of the new generation of growing 2009. 18 1. to provide schools, hospitals and housing technologies to address these needs in our Owen J. (2008). Blurring the boundaries. The estates in cities and towns with the means urban environments. q RHS Garden : October, 2008. to grow their own fresh vegetables in a

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