ForumThe Power of Polyacrylamides
Futurists often pinpoint three frontiers for scientific discoveryinformation
technology, bioengineering, and materials science. Information technology
harnesses computer power to analyze data faster than ever. Bioengineering
uses renewable biological substances in place of nonrenewable ones in
products for business, agriculture, and health care. Materials science
leads to new uses of such compounds as ceramics, plastics, and polymers.
All three affect ARS research
on management of Earth's soil and water. An article in this issue describes
a materials science technology that is keeping water cleaner, saving
soils from eroding, and forestalling unwanted spread of certain nutrients
and microbes from fields and feedlots. (See story on page 4.)
These remarkable accomplishments stem from ARS research on optimum
use of environmentally safe, food-grade compounds known as polyacrylamides,
or PAMs. Importantly, these studiesfrom ARS scientists based at
Kimberly, Idahoprove that growers need use only a few pounds an
acre of this polymer to achieve impressive benefits. PAM, easily added
as a powder to irrigation water, does all of this at an annual cost
of only $10 to $20 an acre. Even better, PAM applications don't disrupt
routine farming operations.
Interest in polymers and other chemical soil stabilizers has come and
gone before. This time around, however, our scientists have a better
choice of polyacrylamides. When applied according to ARS-developed strategies,
these new-generation chemicals are 10 times more effective than earlier
compoundsat only a hundredth the cost. That has made mainstream
use on America's irrigated farmlands a reality.
Though early ARS studies in the United States focused primarily on
furrow irrigation, our ongoing research is also providing practical,
effective guidelines for growers who use sprinkler or surge irrigation.
And this is only the beginning. Imagine being able to use these polymers
to make it easier for water to enter soil. Conversely, imagine using
PAM and a surfactant to prevent unwanted seepage.
Preliminary results from continuing experiments suggest that ARS scientists
will succeed in developing each of these new roles for PAM. For example,
their work indicates that PAM easily, rapidly, and cheaply helps seal
leaky, unlined irrigation ditches and canals. PAM might thus greatly
reduce water loss while providing an exciting new alternative to today's
more expensive and difficult-to-install concrete or plastic canal-lining
This application was demonstrated on an irrigation canal upslope of
the historic Hagerman Fossil Beds National Monument in Idaho. There,
seepage could erode and slough away prized fossil-bearing formations.
Today, the raw material used to produce most PAM is natural gas. It
has usually been cheap and abundant. However, that may not always be
the case. So the polymer industry and ARS scientists are working to
ensure that the important role of these and related polymers can continue,
even if natural gas and other fossil hydrocarbon sources become unavailable
or too expensive.
The polymer industry already knows how to produce PAM and other polymers
from vegetable oils, for instance. In another approach, ARS scientists
at Kimberly and at Albany, California, are investigating polymers produced
from crop residues and food-processing wastes. These PAMs would create
new markets for those agricultural leftovers.
The effort is part of the Natural Resources and Sustainable Agricultural
Systems research programs. Conducted at a cost to each U.S. citizen
of only about a penny a week, this ARS research yields benefits for
everyone. Among them: cleaner air, because well-managed soil doesn't
become airborne dust; cleaner water, because pollution from soil, nutrients,
and microbes is diminished; and affordably priced food for your shopping
cart, because growers don't face costly loss of fertile topsoil.
Of course, the discoveries are applicable not only in the United States, but in many other parts of the globe, as well. Natural resource managers everywhere are continually on the lookout for new developments in information technology, bioengineering, and materials science to meet the increased demands on agriculture. These technologies may prove especially critical for countries where populations are burgeoning, living standards are rising, and pressure on limited natural resources is likely to increase. In those countries, ingenuity and innovative application of these technologies to agriculture may be key to prosperity and to protecting the environment.
Allen R. Dedrick
"Forum" was published in the July 2002 issue of Agricultural Research magazine.