November 4
Water Quality in Agriculture: Why it matters
Water Quality in Agriculture: Why it matters
In his book "Plan b 2.0", dr. letter Brown describes water as a limited but renewable resource on
which we are placing untenable demand. How is agriculture impacting water use
and quality and how will water availability affect our food system in the
future?
According to Brown, the world is facing
a vast water deficit. Because much of
the deficit comes from aquifer over pumping, it is often not apparent. The
drilling of millions of irrigation wells has pushed water withdrawals beyond
the recharge of many aquifers all over the globe. Among the more visible manifestations of
water scarcity are rivers running dry and lakes disappearing. According to
Brown, the link between water and agriculture is strong. It is estimated that
the water required to produce our daily food totals at least 70% of all water
use, mainly in the form of irrigation.
Agriculture is also a major cause of
degradation of surface and groundwater resources through erosion and chemical
runoff. Agriculture overuse of water is responsible for the discharge of
pollutants and sediment to surface and groundwater, through the net loss of
soil by poor agriculture practices, and through salinizations and waterlogging
of irrigated land. In addition, the downstream degradation of water quality by
salts, agrochemicals and toxic leachates is a serious environmental problem.
Agricultural pollution also has negative effects on human health. Nitrogen,
arsenic and hydrocarbon levels in groundwater have severely affected the health
of many communities around d the world.
According to a quote by David Seckler
from the International Water Management Institute, the penalty for
mismanagement of this valuable resource could be catastrophic, for the world as
a whole.
Some had proposed as an important first step to find out what is the long term rate of
recharge for every groundwater basin or aquifer. This would help establishing
the limit of sustainable use. The second step, she suggests, is for all concern
parties to devise a plan for balancing pumping with recharge. If current
pumping exceeds the sustainable limit, achieving this goal will involve some
mix of pumping reductions and artificial recharge by applying the process of
channeling rainfall or surplus river water into the underground aquifer, where
it is possible. The implementation of this plan will need to be accompanied by
legal principles that elevate the public interest over private rights.
This would address several issues at a time, however it is going to take
some time to bring this plan into practice, in the mean time, prevention is
better than cure, and prevention can be achieved by the implementation of
sustainable agricultural practices, and public awareness campaigns on the
imminent deficit of water.
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