With climate change predicted to increase the severity and frequency of drought events in many part of the world, water conservation is a growing concern. New water retention technology developed at Michigan State University (MSU) could help quench the thirst of parched crops while using less water, not only enabling crops to better deal with drought, but also improving crop yields in marginal areas.
Coarse, sandy soils found in semi-arid and arid regions have large pores that absorb large quantities of rainfall. However, they retain less than 20 percent of the water in the root zone that sits between the surface and depths of 60 to 70 centimeters (24 to 27 inches), leaching losses of nutrients and other chemicals into ground water as the water drains away.
The subsurface water retention technology (SWRT) developed by Alvin Smucker, MSU professor of soil biophysics and MSU AgBioResearch scientist, strategically places polyethylene water barrier films at various depths in the soil. The membranes are flexible, allowing them to be shaped to maximize water retention and provide space for root growth.
The films, which are installed using a specially designed barrier installation device (BID), retain water within the upper 70 to 100 centimeters (27 to 39 inches) of the soil, which Smucker claims has the potential to increase water retention efficiencies by up to 20 times. With proper spacing of the films, excess rainfall is also able to drain away.
Aside from the potential water savings, the films also promise to cut fertilizer costs and reduce groundwater contamination by agricultural chemicals. The polyethylene barriers are also faster and less labor intensive to install than asphalt barriers, as well as being more durable, lasting at least 40 years.
Prototype tests carried out in drought conditions saw irrigated sands produce 145 percent more cucumbers than control fields without the films, and also increased corn yields 174 percent. In addition to agricultural crops, the technology could also be used to increase the yield of cellulosic biomass feedstock used for fuel production that are grown on marginal lands.
“This technology has the potential to change lives and regional landscapes domestically and internationally where highly permeable, sandy soils have prohibited the sustainable production of food,” Smucker says. “Water retention membranes reduce quantities of supplemental irrigation, protect potable groundwater supplies, and enable more efficient use and control of fertilizers and pesticides.”
A team will test the patent pending technology “in the field” on farms in irrigated sandy regions of southwestern Michigan as well as semi-arid and arid regions of the south western and mid western U.S. with MSU researchers also looking at implementing the SWRT films in global locations susceptible to drought.
Smucker is working with MSU’s technology and commercialization office, to commercialize the technology.
Source: MSU
Is it a back hoe with a plastic dispensing roll?
Pretty clever idea overall, none the less. I'm sure it will benefit many, many people.
It would be prohibitively expensive to displace tons and tons of earth in every field to lay these down, and then bury them again. The article talks about multiple depths, I hope that doesn't equate into multiple layers, b/c then problems compound. Machinery costs, not to mention huge fuel usage for such an operation. Also, as another poster added, you're putting plastic in the ground. On top of environmentally toxicity, it would impede much of the soil's natural micro-biological flora, depening on how deep it was layed. It would destroy any hopes of earthworms doing their work on the surface and bringing organic matter down and the other host of good things they do, also providing an "airtight" seal below the plastic, shutting off access to air and creating an anaerobic environment that pathological bacteria thrive in. Also, in many areas of the world this could lead to significant salt buildup, which could become toxic buildup in such a set-up. Same goes for chemical build-up.
I hate to sound critical. The best way, IMHO, is always to use the natural way that God set-up...it works perfect when we don't crop our lands in to oblivion with all our chemicals and over-use without regard to feeding the soil. Another words work with it, not against it. The best way to retain both bio-available fertility and water retention, and foster a good aerobic environment, is to have sufficient organic matter in the soil, which is largely missing in today's mono-cropping ag system. Cover crops like Alfalfa, vetches, ryes and various legumes which fix nitrigen naturally are key, which add organic matter, stabilize soil structure, increase tilth, prevent leaching of nutrients and even mine nutrients from deeper down, bringing it up. (plastic layering would get in the way of these roots too). These crops can be plowed under also, to be used as a green manure. Of course PH management is crucial as well. Sandy soils have very low cation exchange rates, meaning they cannot hold much by way of nutrients, so semi-regular, light foliar fertilizer applications may be necessary, esp. when first trying to recover soil conditions. Natural fertilzer is vastly preferable to chemical, salt-based conventional fertilizers.
The bottom line is there is no easy way to do this...it takes lots of work and long-term commitment. Problem is today farmers and society want instant production, instant crops, without long-term investment, planning and work, and easy, instant fixes to the problems that keep arising and growing through decades of such practise (constant, season long chemical spraying, GMO's, which do more harm than good, etc.) All these conventional practises and chemicals do vast harm to soil ecosystems and interrelated systems, which has huge implications in terms of bio-availability of soil fertility, etc: soil micro-boilogy has to be there! Crops and end consumers suffer as a result, as defiencies and compromised food quality follow.
Just read accounts of how extremely bio-diverse much of our countries were like 100 years ago, with thousands of insects buzzing around, scores of birds, many various types of animals, etc, etc. People could break ground for the first time 50 years ago and have instant bumper crops, without chemical fertilizers. Not anymore! Now many of these large commercial farming opertions are home to the plant being grown, and not much more. We are already "reaping what we have sown"...no pun intended. It will get worse if sustainable practises are not implemented fast. Many of the big commercial ag guys still laugh at these ideas, but they won't laugh anymore when fertilizer costs double/triple with oil costs again someday, and they can't afford to fertilize anymore, and then the soils will not be able to produce in their current shape. But then we'll all be screwed.