Wednesday, May 21, 2014

Nebraska Nitrogen management & Central Platte Natural Resources Conservation District

We met with professor of soil fertility, Dr. Richard Ferguson, from the University of Nebraska, Lincoln to discuss nutrient and water management issues. He works closely with the Central Platte Natural Resources District (CPNRD).

The Central Platte is one of 23 Natural Resource Districts in the state. These districts are a local governance structure that can levy taxes, impose regulation and provide cost-shares for various conservation goals. Each district has staff on board and is headed by an elected board of directors made up of both urban and rural residents, farmers and other interested individuals. Each district is subject to the State of Nebraska Department of Environmental Quality for approval for funding and regulatory measures. The CPNRD is broken up into 24 different management zones.

This governance organization is significant for nutrient management as the impacts of nutrient loss on agricultural land are complex and far reaching, with many stakeholders. Under this organizational model, regulation can be passed by the farmers and their neighbors, rather than top down by higher level groups. As 95% of drinking water in Nebraska is untreated groundwater, everyone has an interest in protecting this resource. After many years of high volumes of irrigation water, highly-leachable nitrate is en route to aquifers that supply drinking water. This can pose potential health problems for both humans and livestock.

Project manager and extension specialist from University of Nebraska for the Central Platte Nitrogen and Irrigation Project, Dean Krull, spoke with us and described the efforts being made to characterize farmer's irrigation practices. Water used for irrigation is of particular importance to both water quantity and quality available to residents of the Platte River Valley. Then, the CPNRD hydrologist, Duane Woodward spoke with us about efforts being made to characterize water quality throughout the Central Platte. Approximately 1/3 of about 750 water wells in their district are sampled annually for nitrates.

The CPNRD uses a three phase system for regulation of water quality with respect to nitrate. In the highest regulated phase, several common farming practices are prohibited to prevent continued degradation of water quality. Particularly: no fall application of N, no preplant N without an inhibitor, encouragement to split N applications, requirement for fertility and irrigation recommendations based on soil testing and analysis of water nitrate concentrations.

As we move forward, regulation will be an increasingly important factor in the protection of water quality and mitigating N loss. Often economics and environment are at odds with one another. The CPNRD is an excellent example of a bottom up regulatory system; a novel approach for dealing with the potential problems of N pollution throughout our highly productive agricultural regions. Whether we will be able to continue to produce the high yields the way we have without losing nitrogen in excess of the 10 mg/L maximum contaminant level for drinking water remains to be seen. Unfortunately, even with the best regulatory and fertility practices in the Central Platte area, nitrate will continue to travel through the vadose zone towards aquifers for years to come.

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