as those from furnaces, contain pollutants
such as sulphur dioxide and ethylene which
significantly damage plants. This means a
vertical farm requires a CO2 source, most
likely from combustion. Also, necessary
ventilation may allow CO2 to leak into the
atmosphere.
Greenhouse growers commonly exploit
photoperiodism in plants to control whether
the plants are in a vegetative or reproductive
stage. As part of this control, the lights
stay on past sunset and before sunrise or
periodically throughout the night. Single story
greenhouses have attracted criticism over light
pollution.
Hydroponic greenhouses regularly change the
water, producing water containing fertilizers
and pesticides that must be disposed of.
The most common method of spreading
the effluent over neighbouring farmland or
wetlands would be more difficult for an urban
vertical farm.
ADVANTAGES
Many of VF’s potential benefits are obtained
from scaling up hydroponic or aeroponic
growing methods.
A 2018 study estimated that the value of
four ecosystem services provided by existing
vegetation in urban areas was on the order of
$33 billion annually. The study’s quantitative
framework projected annual food production
of 100–180 million tonnes, energy savings
ranging from 14 to 15 billion kilowatt hours,
nitrogen sequestration between 100,000
and 170,000 tonnes and storm water runoff
reductions between 45 and 57 billion cubic
meters annually. Food production, nitrogen
fixation, energy savings, pollination, climate
regulation, soil formation and biological pest
control could be worth as much as $80–160
billion annually.
Preparation for the future
It is estimated that by the year 2050, the
world’s population will increase by 3 billion
people and close to 80% will live in urban
areas. Vertical farms have the potential
to reduce or eliminate the need to create
additional farmland.
Increased crop production
Unlike traditional farming in non-tropical
areas, indoor farming can produce crops
year-round. All-season farming multiplies the
productivity of the farmed surface by a factor
of 4 to 6 depending on the crop. With crops
such as strawberries, the factor may be as
high as 30.
Furthermore, as the crops would be consumed
where they are grown, long-distance transport
with its accompanying time delays, should
reduce spoilage, infestation and energy needs.
Globally some 30% of harvested crops are
wasted due to spoilage and infestation, though
this number is much lower in developed
nations.
By Michael Rivera - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=58216575
AgriKultuur |AgriCulture
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