No easy solutions for nitrogen run-off
by John McLaughlin, posted May 6, 2010
Chemical fertilizers, in part, make it possible to feed the nation. However, while increasing crop production sustains an ever-growing population, nitrogen run-off from chemical fertilizer use creates an ever-growing problem in the form of toxic tap water and dead waterways.
According to the Environmental Working Group, a non-profit environmental research organization, 80 percent of nitrogen contamination comes from agricultural practices that use chemical fertilizers.
Because of the lack of legislation limiting non-point source contributors, the regulation of nitrogen contamination is voluntary if not non-existent, according to Clark Gantzer, MU professor in the school of natural resources.
“If you can envision in 1970, the dream was [in] five years [to have] swimmable and fishable waters in the whole United States, and it is now 2010 and we have yet to realize that goal, he said.”
Research published on the Environmental Working Group website says that excessive nitrogen consumption from contaminated water sources can lead to an increased cancer risk, methemoglobinemia (a life threatening oxygen deficiency in the cell tissue of babies and adults known simply as blue baby), hypertension, a malfunctioning thyroid (the thyroid is vital to the function of the endocrine system), and chronic birth defects in newborns.
Nitrogen contamination begins in the fields of agriculture and moves on to greatly affect even some of the largest bodies of water.
For example, glut amounts of nitrogen from agricultural areas within the Mississippi river basin continually run into the Mississippi river and eventually into the Gulf of Mexico.
Once in the gulf, the nitrogen feeds growing algae blooms whose decomposition process expends available oxygen in the water, which creates large oxygen deficient areas of that are unable to sustain plant and animal life.
These particular areas, known as dead zones, are increasing in abundance worldwide, and can be found not only in the Gulf of Mexico, but also off the coast of Washington in the Northwest, the coast of Maine in New England, nearly every coast line of Europe — including the Black Sea, and the south coast of Japan, according to images provided by NASA.
Environmental legislation, such as the clean water act and the national environmental protection act of the 1970s, has siphoned off the problematic industrial point source polluters and their easily detectable toxic discharge pipes.
However, it is not easy to detect non-point sources such as urban and agricultural contributors.
The problem is intricate, and the goal must be to balance our use of agricultural chemicals considering the effects of those chemicals have on the environment.
“All of our chemicals have risk and have benefits. We use herbicides for a reason, and we use pesticides for a reason, but we have to be careful and use them in the most appropriate way that we can and balance that with what some of the possible effects are. Good environmental policy is going to have to balance between the risks that come from agriculture and the fact that we need to provide food," said Tim Evans, of the MU
department of veterinary pathobiology.
While nitrogen does wreak havoc on the environment, solutions do exist.
Farmers in the past have participated in a practice known as a riparian buffer.
Riparian land types are those that border waterways, including creek and river edges, and this is where most of the nitrogen enters the water when it doesn’t seep deep underground and into springs.
Trees are commonly used as riparian buffers, which are intended to catch the excess nitrogen before it reaches the water.
The idea is that plant roots, of trees or whatever plant type is used for the buffer, soak up the excess nitrogen. Riparian buffers help to remove nitrogen on land before it can create problems in the water.
However, these buffers often fail, according to nutrient management specialist Peter Scharf of MU
If you’re looking for a quick fix, there is none. However, there are things that are practical but difficult, according to Scharf.
Scharf has been researching the use of technology that can monitor crops and electronically control the amount of fertilizer released.
Sensors mounted to farming equipment are able to distinguish between the color shades of crops and apply fertilizer accordingly.
Bolder shades of green receive less fertilizer than lighter shades, and the process has shown an increase in yields and a reduction in the amount of fertilizer used.
In one instance, Scharf has seen a reduction in nitrogen by 16 percent without affecting the crop yield and without run-off.
Scharf’s research includes 157 different fields, and has effectively reduced the amount of run-off by eliminating the excessive usage of fertilizer. Only the amount that is needed is applied.
Technology can be expensive, but government subsidies exist to alleviate the burden.
“If there is no incentive for [farmers] to reduce usage, you have to pay them to do it,” Scharf said.
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