The World Economic Forum (WEF) has now published it’s “Global risks assessment survey” with the results of members responses on the five most important global risks over the next ten years. Respondents ranked the impact of water scarcity as the greatest threat facing the planet over the next decade before failure of climate-change mitigation and adaptation (2nd), extreme weather events (3rd), food crises (4th) and profound social instability (5th).
It is not surprising that all of these risks are closely linked but it is remarkable to note that as recently as 2010, water scarcity was not even listed in their analysis.
Furthermore the science journal Chemistry & Industry (November 2015, p 18) reports that 13 of the world’s largest 37 aquifers have now been depleted to the point where water availability is threatened in some key agricultural regions, including East and South Africa which are currently experiencing the worst droughts in 30 years.
Mankind has no other choice but to start managing water resources better as well as improving water use efficiency (WUE) in all sectors of agricultural, industrial and domestic household consumption.
And as agriculture is by far the largest consumer of water in both developed (61% of total used) and developing countries (85% of total used), then without any doubt this is the best place to focus for improving WUE.
Currently in developing countries water is applied to crops mainly using field or furrow ‘flood’ irrigation which works reasonably well but the WUE by the crop is only about 30-35% of the water applied.
However when the more controlled ‘drip’ irrigation practice is employed with plastic piping to deliver water in lower amounts close to the growing plants then crop WUE increases 2-3 times up to 85% of water applied.
In simple terms this means that 2-3 times ‘more crop per drop’ can be achieved for the same volume of water applied by drip irrigation representing a very simple and easy to apply method to fight imminent water scarcity.
Even in temperate countries with high rainfall the use of drip irrigation has been found to improve WUE and increase yields as it helps manage the crop’s water balance throughout the growing season more effectively.
“The move from flood to drip irrigation in regions of increasing water scarcity is neither difficult nor expensive even for small-holder farmers – a simple, robust pump; piping to deliver water to crop rows; and plastic tubes with regularly spaced ‘drippers’ near to plant bases – costing a few hundred dollars and it’s ready to go” says Dr Kevin Moran of Kemnovation.
He adds “Furthermore the efficiency of applied fertilisers can be greatly increased when metered into irrigation water – a process called fertigation – and I predict this practice will have profound benefits for using both water and fertilisers much more efficiently in future – achieving MORE with LESS for a growing planet!”.
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