Vetiver System and the Control of Rainfall Runoff

John Greenfield’s note (http://www.vetiversolutions.info/2013/05/the-essentials-of-rainfed-farming-in.html) on the essential need to control rainfall runoff is indeed very much to the point.  A recent study by Herve Plusquellec indicates that over the past 50 years the world’s irrigated lands more than doubled from 140 million to 309 million ha. This increase, together with plant breeding (high yielding wheat and rice) and fertilizer, contributed to powering the Green Revolution ensuring that there is generally enough food to feed the world’s population. FAO projects that world wide irrigated areas may only have a net increase of 0.12% in the next 40 years.  Currently surface water supplies are already overstressed and ground water is being mined to the extent that in some areas levels are dropping by as much as 2m per year.  These figures are pretty worrying, and clearly point to the need for alternative solutions for growing food if serious short falls are to be avoided.  Greenfield rightly points out that this has to come from non irrigated lands and better use of rain water, and in particular reducing the amount of rainwater that runs off farm land, that in the flood season is eventually discharged into the oceans, often creating great damage in the process.  In the past the emphasis on, and large investments for the construction of large reservoirs (and complimentary irrigation systems) for storing water, for flood control, and for irrigation received much higher priority than dealing with dryland agriculture.  For the future there is a need to give a lot more attention to insitu storage of water (groundwater) and reducing floods by taking a lot more care of our agricultural lands, and the restoration of land that is often referred to as waste land (unproductive crop land and land that has been deforested).  The Vetiver System when applied under these conditions has shown how runoff can be reduced by as much as 70%, benefiting both soil moisture for crop production, and ground water recharge. I have commented before on this blog - http://vetivernetinternational.blogspot.com/2011/03/food-security-and-vetiver-system.html - about how Vetiver can be so effective in this area of water conservation. Other similar notes are at: http://vetivernetinternational.blogspot.com/search?q=climate+change. Whether we want to believe it or not, the climate is changing, weather patterns are becoming more extreme, rainfall events are often fewer in number and more intense, resulting in flooding and great loss of water, as well as eroding land and destroyed crops. 

Although there are some very encouraging developments taking place in many countries in the application of the Vetiver System for these and other purposes, there is a real urgency to do more to convince government policy makers, international aid agencies, technical specialists, farmers and others of the value of the Vetiver System as one of the critical technologies that can be economically and widely applied in the tropics and semi-tropics for the purpose of water conservation and sustainable food production.

Dick Grimshaw