Hydroponic agriculture farming –opportunities in urban agriculture

The world’s population, we all identify that, is growing rapidly. The World Health
Organisation (WHO) figures it will increase to 9.7 billion people by 2050, including 70% of
human population living in urban zones. This scenario also applies in our country. Everybody
is aware of brisk growing of urbanisation in Nepal in over the periods. Therefore, the demand
of food production will be double to compensate the food security where the traditional
methods of agriculture are yet challenging to fulfil the upcoming food shortage.
Similarly, the modern-day agriculture producing a lot of food is one of the reasons for the
destruction of our planet. Moreover, extreme use of pesticides and agro-chemical products
along with mechanization not only deplete the topsoil but also increase the environmental
pollution and degradation. Such natural disaster result an alarm to food security for billions of
people in near future. Hence, the soilless system cultivation can be surely an alternative
opportunity towards eco-friendly agriculture as well as bright mechanism in the outlook of the
general challenge of food security. At present, around 3.5 % of cultivated area under tunnels
and greenhouse especially horticultural and floricultural production across the world endorse
the soilless cultivation consisting of hydroponic techniques. In context of Nepal, most of the
cities convert into concrete jungles at speed, hence hydroponic agriculture can be a possible
substitute as well in modern era. The term ‘Hydroponics’ means growing plants in water,
derived from two Greek words ‘hydro’ and ‘ponos’ meaning ‘water’ and ‘toil’. Hydroponic
agriculture is a type of farming or gardening techniques, which does not depend upon soil.
That means without soil. Without soil…..growing plants with any soil, but how? Let us have a
closer look at hydroponics and its mechanism.
Generally, plants grow through a process called photosynthesis using the sunlight for
chlorophyll. They do need the fundamentals such as water, moisture and nutrients for their
growth, which can easily get from soil. Soil is just the most available and supportive medium
for any plant life. However, if plants fulfil their necessity by their roots dipping in a required
nutrient-rich solution, they will not need soil for nutrient and water transport. This is a basic
principle of hydroponics. Many hydroponic producers get more yields comparing to
conventional methods. Hydroponic plants also grow faster relatively. Moreover, the problems
of open field agriculture are probably very high due to availability of land and agriculture soil
fertility, unfavourable topographic conditions, and some urban areas where the capacity of
land agriculture is limited, under such limitations soilless farming will practice successfully.
Countries as Egypt and the Middle East with deserts are successfully practicing hydroponic
agriculture and capable of addressing local food needs. Scientists are even attempting to
utilize this technology on the International Space Station to grow food for astronauts so that
they can stay in space for longer missions. Especially in regions with extreme climates or
inadequate rainfall, it may have many advantages for large-scale commercial agriculture. In
the developing countries like us, hydroponic greenhouse cultivation will rise quickly among
other agricultural areas.
In this system, farmers can grow food almost anywhere like setup in homes, greenhouses, or
any indoor space where they can grow plants all year round under controlled conditions with
countless benefits. Growing crops in towers can solve the problem for need of more land.
Hydroponic farming mostly support profitable crops like cereal, green leafy vegetables,
peppers, cucumbers, flowers and fodder and of course tons of tomatoes. Rice, in the other hand, is possible to harvest four times annually in hydroponic technique, instead of single
harvest in conventional agriculture.
Another advantage of this system is minimum use of pesticides and other harmful agro-
chemicals that increase the yield while conventional agriculture relies heavily on chemical
herbicides and pesticides. Growing without soil generally gives more hygienic growing
system with fewer problems of disease. Besides, soil is also responsible for various
microorganism and nematodes present in it, poor drainage, soil compaction, and soil
degradation. In addition, our world faces increasing challenges with desertification and
climate change, hydroponics may play a valuable role in feeding humanity. Additionally,
hydroponics consumes around 90% of less water than traditional field crop during irrigation
due to their recirculation techniques to minimize waste. Thus, pesticide-free and moving from
the traditional tractor agriculture that is steadily destroying the planet to a more sustainable
approach.
Hydroponic technology consists of many small methods. Aeroponics is a method of growing
plants in a nutrient-rich aerosol a bit like a cloud packed full of minerals. The aeroponics
culture is usually practiced in protected structures for low leafy vegetables like lettuce,
spinach, etc. Aquaponics, on the other hand, combines elements of aquaculture and
hydroponics. This culture permits the producers to grow and produce plants in a sustainable
way with fish farming together within the local community.
There are important environmental factors which effect the hydroponic greenhouse
production e.g., light, temperature, air humidity, and CO 2 concentration. The major advantage
of hydroponic greenhouse cultivation is efficient usage of natural light to develop fruit
simultaneously. Approximately, seventeen elements (macronutrients and micronutrients) are
required for proper plant growth. Supply of nutrient solution to the hydroponic crops mainly
depends on two parameters named as pH and electrical conductivity (EC).
Hydroponic greenhouse system can play a vital role for the food production in the future. The
future of this technology is very bright because as country’s population increases, agricultural
land comes under colonies so to overcome such situation we will need unique system that
produce food with limited inputs, hydroponic greenhouse system is only system, which could
meet the food requirement according to our needs. Hydroponic greenhouse system has an
ability to feed millions of people in future in third world countries because water and crops
are scarce/threaten in those regions although installation cost is high but in the long run all
cost will decline, that will make this technology more feasible and convenient.
But hydroponic agriculture also relies on large amounts of plastic and other non-renewable
components. And some commercial hydroponic operations can use chemical nutrients that are
not sustainable, and that may even lack important minerals. Perhaps most concerning,
hydroponic agriculture is a missed opportunity to use agriculture to sequester carbon and
enhance soil health. But despite its benefits and downsides, hydroponic agriculture is
probably here to stay and is expected to expand gradually.

JENISH NAKARMI
PhD , Agricultural Sciences ( Molecular Phytomedicine)
INRES, University of Bonn
GERMANY