Vertical hydroponics unit
Further Discussion
Main objective of this pilot was to demonstrate the potential and effectiveness of simplified hydroponics as an appropriate crop production technology for different categories of communities in various contexts with particular reference of its use in very small areas of urban houses.
Results of all 15 pilot projects demonstrated the applicability of the simplified hydroponics technology for various settings and for different categories of people.
Although this was not one of objective, we had one person who was recovering from mental illness and the pilot project demonstrated the potential of this technology as a vocation for people recovering from mental illnesses. Simplicity of operations makes this technology amenable for them with little outside help for such activities as the preparation of the nutrient solution in bulk. Patients’ involvement in various activities in maintaining the garden can also be used as a horticultural therapy the effectiveness of which needs to be further explored. Even though we have not yet conducted a pilot project it is a reasonable assumption that this technology has equal potential to be used by physically challenged people and also the elderly.
Post project evaluation conducted with the involvement of participating families has revealed the following; 1) Considerable time saving for the maintenance of hydroponics units. Once the units are set and the transplanting was over it took only 15-20 minutes on average per day for the maintenance hydroponics units. These include the daily supply of nutrients. It was mentioned that this is well suited for women particularly with small children
to balance their daily household chores with home gardening. Those who involved in multiple livelihoods,Students or non-agricultural activities as the main source of livelihood find it easier to cultivate vegetables for consumption at the home garden level using simplified hydroponics since the maintaining of the hydroponics garden could be done at any time of the day at the convenience of the grower. 2) Efficient use of water and nutrients. On average, the consumption of nutrients were about 200ml per day for 12 msq hydro wall and vertical and 400 ml per day for 80 msq units. One participant applied higher doses of nutrients expecting higher yields that resulted in excessive vegetative growth and waste of nutrients. This indicates the particular importance of technical training on nutrient management in popularizing this technology for wider adoption. It was mentioned that the amounts of water were far lesser compared to what is required to irrigate a similar plot of soil grown crops.
Crop yield is considerably higher (at least 2 times)compare to potential yields that could be obtained under soil grown conditions for similar crop varieties as recommended by the Department of Agriculture (Table 1). This is a distinct advantage of the hydroponics technology in general.
Table 1 - Crop yield comparison of simplified hydroponics with soil grown crops
Crop Potential Yield in hydroponics (Tons /ha) Yield in soil (Tons /ha)
Tomatoes 60 20
Brinjoles 104 25
Vigna 93 12
Bitter Guard 37 20
Okra 31 15
Chinese Kale 18 N/A
Cabbage 109 40
In this pilot project, the total green yields obtained from 3.6 m2 space is sufficient to cover about 70 per cent vegetable requirement of a person for a period of 5 months at the present rate of per capita vegetable consumption in Kenya which is about 150g day (personal communication).
CONSIDERING THAT AGRICULTURE IS A MAJOR USER OF WATER, WILL AGRICULTURE PRACTICE NOT COMPROMISE WATER SECURITY IN URBAN AREAS?
Results of this pilot indicate that
140 liters of nutrient solution is enough to support 50 lettuce plants to maturity (around 3 weeks after germination). On extremely warm and dry days, there might be the need to replenish evaporated water. Nevertheless, the nutrient solution after two weeks is still able to grow a second batch of lettuce before more nutrient solution needs to be added. When we consider that 140 liters can support 100 plants using our methods and that our average yield per plant harvested is 25 grams for green wave and 50 grams for fanfare, then
140 liters nutrient solution is required to grow 2.5 kg and 5 kg of lettuce respectively or 56 liters of nutrient solution is needed by green wave and 28 liters is needed by fanfare to grow to 1 kg. The global average water footprint of 1 kg of lettuce is equivalent to 130 liters. The water footprint of our methods is less than half of the global estimates.
POLICY ISSUES ADDRESSED
This pilot project addressed the following issues: First, it addressed the need for agriculture products to be grown locally and consumed on site. This type of agriculture emphasizes the following characteristics: 1. It is grown on site, therefore reducing the cost of transportation and spoilage; 2. It meets the demand for on-site food supply, i.e. the immediate deployment of food through an existing food delivery infrastructure (canteens). Second, the project utilized an underdeveloped and vacant urban space resource and transforms them for productive use. Third, it employed a type of agriculture, hydroponics, that does not use soil but, in this case, a continuous flow of water to grow food. This type of agriculture uses only 20% of the water requirements for traditionally grown agriculture, thus, saving a valuable resource – water.
POLICY RECOMMENDATION
The results of this pilot study show that urban farming in urban
is not only feasible but is also productive. The growing time is not only shorter and the yield, higher, but the set up can also be designed so that ecological foot print of the methods used is drastically reduced. It is not because food crops need not be transported from distant places, but energy is saved by using alternative sources of power supplies such as solar powered pumps.
Furthermore, water conservation is also enhanced by the hydroponic method adopted in this study. It has been shown that urban farming does not only address food security issues but also proves to be environment friendly. Hence, the practice should therefore be encouraged.
Table 2 – Results of socio-technical assessment of the process in the project
System Characteristic Comments from participants
Time spent All spent less than 30 minutes/day
Labor efficiency All agreed that the labor use was minimal for this process.
Operations All agreed on the ease of operation
Water use All were on the opinion that amounts w ere much lesser
Nutrient solution
preparation and use All have done accurately as instructed.
Land ownership Only one participant owned land less than 60 by 80 ; others about 1/8 of acre or more.
or more.
Reasons for interest in
the technology 1. Problem in soil; Interest in new technology
2. Limited land for cultivation and the interest in new technology
3. Ability to engage in home gardening along with other household duties
4. Interest in new technology and to explore the potential for commercial cultivation
Involvement of other
members in the family All the participants had been helped by the husband as well as children
irrespective of the age.
Suggestions 1. Inputs supply on commercial basis and extension services need to
continue to ensure the sustainability
3. Explore potential for growing ornamental plants and spices
4. Low cost Innovations in the system to use this technology in commercial cultivation of high value crops.
5. Develop tall vertical units to ensure cities feed themselves.
Accordingly, if simplified hydroponics technology is used, the space required to satisfy the vegetable needs of a family of four will be around 9.4m2. Above all, pesticide free fresh produce improves the health of growers and consumers while the green environment creates a peaceful atmosphere. These findings are important in designing urban homes and flats with provision of some space for agricultural production.
