In summary world wide ground water levels are falling so fast that grain supply is threatened. In major grain producing countries including the US, China, Mexico, India, and Pakistan, irrigation water is falling below its peak, with consequent potential disruption of grain supply resulting in significant increases in grain prices. This is particularly troubling where in India, most of the irrigation water is from ground water, and and that ground water is depleting at rates of more than 2 meters a year It is so bad in India that Government no longer publishes information on ground water supplies. Additionally, these countries that are heavily dependent on irrigation, also have large population centers that are also increasingly dependent on diverted agricultural water. Lester Brown also notes that apart from the "water "problem, increasing soil erosion is reducing agricultural harvests and new dust bowls are being created. Lester Brown is not an alarmist, he has the sober facts to back up his views. His penultimate paragraph "The bottom line is that water constraints augmented by soil erosion, the loss of cropland, a shrinking backlog of unused agricultural technology, and climate change are making it more difficult to expand world food production. Is it possible that the negative influences on future food production could offset the positive ones during this second decade of the century?"
Not all is lost, of course new technologies are being developed that reduce crop demand for water or make better use of existing water supplies, but the fact remains that the world is at a critical point, and that it is even more critical with the advent of climate change.
John Greenfield has written extensively about the role of the Vetiver System for soil and moisture conservation. His most recent article, "The Essentials of Rainfed Farming in Subsistence Agriculture" can be found in the Vetiver Solutions blog at: http://www.vetiversolutions.info/. We have conclusive evidence, on large scale from Ethiopia, of the impact of Vetiver grass hedgerows for protecting farms from erosion (90% reduction), for increasing crop yields (30% increase) and for recharging ground water (up to 70% reduction in rainfall runoff). Just read the relevant papers on the most recent Vetiver Workshop held in Ethiopia - http://www.vetiver.org/ETH_WORKSHOP_09/ETH-OO%20Proceedings.htm and the many articles and research papers at the TVNI website: http://www.vetiver.org
The Vetiver System is not just for small farms, larger commercial farms should and do use vetiver hedgerows successfully for soil and water conservation. The Vetiver System is one of a number of technologies that can be applied to mitigate these problems, and policy makers should take the technology into consideration when creating strategies that will offset the "water problem" described by Lester Brown. TheVetiver System not only conserves soil and soil nutrients; it also spreads rainfall runoff more evenly across the land, and because of its powerful root penetration it opens up hard pans to allow for greater ground water recharge. It is probably the least cost and lowest labor intensive technology available, and it works! Governments and development aid agencies, including the World Bank and the World Food Organization, continue to support costly "hard" technologies for soil and water conservation that are not very always effective, that often could be replaced for the better by the Vetiver System.
I would urge readers, even if your interest is mainly focussed on non agricultural VS applications, to forward the link to this blog to local or state policy makers, university faculties, and others that you might know, drawing their attention to the potential of VS, as part of the solution to looming water issues.