A sign of waste

Wednesday, December 26, 2007

Environmentalists are warning that the increased demand for corn will likely cause the growth of the 'dead zone' in the Gulf of Mexico. Because of rising demand for ethanol, American farmers are growing more corn than at any time since the Depression.

The nation's corn crop is fertilized with millions of pounds of nitrogen-based fertilizer. When that nitrogen runs off fields, it makes its way to the Mississippi River and eventually pours into the Gulf, where it contributes to a growing "dead zone" -- a 7,900-square-mile patch so depleted of oxygen that fish, crabs and shrimp suffocate.

The dead zone was discovered in 1985 and has grown fairly steadily since then, forcing fishermen to venture farther and farther out to sea to find their catch. For decades, fertilizer has been considered the prime cause of the lifeless spot.

As bad as this dead zone is, it is only one of the problems resulting from what is obviously poor conservation practices.

Nitrogen should not be running off of fields in significant quantities. Buffer strips should be used to both minimize fertilizer runoff and control soil erosion.

Planting of corn should be rotated with nitrogen fixing crops such as soybeans in order to reduce fertilizer demand. Organic matter needs to be worked into the soil to improve the soil quality, which allows the soil to hold more moisture, reducing runoff and increasing the efficiency of plants in the uptake of nutrients.

Soil evaluation should be used to determine the amount of fertilizer needed.

Using more fertilizer than is needed not only threatens water quality in the Gulf of Mexico, it affects water quality of inland waterways and wastes energy used in manufacturing the fertilizer.