District meeting on resources dominated by water and nitrates | News

The importance of protecting and preserving groundwater dominated the Lower Elkhorn Natural Resources District meeting on Thursday night.

Meeting in committee of the whole in Norfolk, the 15-member council heard three reports related to groundwater levels, nitrate leaching and irrigation management – ​​or a combination of the three topics.

The issue remains relevant as a growing number of city and private wells in northeast Nebraska are being warned about nitrates testing above 10 milligrams per liter. In communities with wells above the threshold, babies, pregnant women and nursing mothers should not drink the water.

The nitrate issue may make some agricultural producers uneasy as they fear additional government restrictions. Still, many of the studies presented at Thursday’s meeting focused on finding the optimal amount of fertilizer growers can apply to their fields to achieve maximum production without leaching.

Also, avoiding overuse of fertilizers benefits farmers as it reduces fertilizer costs. The studies examine issues such as irrigated land, arid land, when to water during the growing season, and the amount of rain or irrigation.

One study, however, which simply looked at groundwater levels, provided mixed information.

Dallas Dorey, a water resources technician for LENRD, showed results that showed most wells in the 15 counties covered by the district are at healthy levels, with many actually having increased water readings. Some of the wells date back to 1976, so there’s a fair amount of data covered.

Dorey said across the district over the past two years, however, the average sink has dropped about 2.4 feet. He and others who check wells have noticed that it looks like a lot of the wells that were near streams were lower last year. It is unclear why this might be.

In 2018, 2019 and 2020, historic water levels were recorded in the district, so many wells were up in those years, he said.

The wells vary in depth. Some are 250 feet deep and some are as shallow as 5 feet, he said.

Crystal Powers, who presented on nitrates at the Nebraska Resource Districts Association conference earlier this year in Lincoln, said pastures and rangelands are lowest for nitrate leaching. Next is turf, then cropland – dry land followed by a pivot – with the most leached furrow, then a few feedlots.

Powers, who is the research and communications specialist through the Nebraska Water Center, said it can be difficult to balance food production, benefits and health and water impacts.

She cited recent studies in Hastings, which has similar rainfall amounts to the Lower Elkhorn area, but obviously different soils.

In the five years that were recently studied, more than half of the fields have over-irrigation, Powers said. The land had soil moisture sensors in a large number of fields to determine appropriate irrigation amounts.

“Sometimes, at the start of the season, it’s too much. Sometimes it’s the whole growing season. Sometimes it’s late,” she said.

The studies provide intuitive results, like putting nitrogen on the plant when it’s needed, which is the ideal route.

Irrigation is one of the main causes of nitration, but irrigation does not make nitration inevitable, she said.

Bazile Groundwater Management Area Extension Educator Jeremy Milander also presented results from the Bazile Groundwater Management Area Demonstration Site in the NRD Upper Elkhorn.

Six different nitrogen levels were tested to create a yield line to try to determine how to get the maximum yield for the input.

No action was taken on the reports that were presented as the board was meeting as a committee of the whole. When the Board meets as a Committee of the Whole, it meets in a more relaxed setting where no action is taken, except occasionally to ask staff to present a resolution or cause of action to the Board at its regular monthly meetings.

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