Article & Photos Estelle Kempen
DEPARTMENT OF AGRONOMY, FACULTY OF AGRISCIENCES
STELLENBOSCH UNIVERSITY
Significant progress in the way we produce our food has been made in the last
few decades including targeted fertilizers and fertilizer programs, advanced
irrigation systems and new varieties that are resistant to many diseases and
offer higher yields.
H
owever, with a world
population close to 7
billion people, more
innovative solutions are
needed to help secure our food
supply for the future in a way that
does not compromise environmental integrity. With the largest increases in populations occurring in
cities, it seems logical to try and
find ways of increasing the output
from urban agriculture. Producing a
larger percentage of our food in
areas with high population densities also cuts down on the transport
and associated costs of fresh produce. An added benefit of growing
food in urban areas is that less land
is needed for agricultural production, allowing the opportunity for
the conservation of larger areas of
rural land and potentially in the
long run even reducing the effects
of global warming.
The most technological advanced
method of urban agriculture is vertical farms where crops can be
grown using hydroponic techniques. These city farms can be a
conventional greenhouse in an urban area, sometimes on the rooftop
of a building or even to be found
stacked on top of each other as
part of large city skyscrapers. A
number of sustainable technologies
can be integrated into one of these
Figure 1: Illustration of what a vertical urban farm
would look like.
vertical farms. The technique of
producing a wide variety of crops,
mostly vegetables and fruits, without soil or in hydroponics has been
around since the 1930s but during
the last decade new inventions has
made this a viable method of producing food in urban areas. Nutrient recipes have been formulated
which means that it can be supplied
to crops at the exact concentration
needed at a specific growth stage
and on-line sensors can monitor the
levels of nutrients as well as the pH
and oxygen levels in the nutrient
solution. The technology also exists
to re-use most if not all of the water and nutrients that is not used by
Figure 2: Inside Nuvege urban farm in Japan.