Water, nitrates dominated resources district meeting | News

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

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

The issue remains timely as a growing number of city and private wells in Northeast Nebraska are being warned about nitrates that test above 10 milligrams per liter. In communities whose wells are beyond the threshold, babies, pregnant women and nursing mothers should not drink the water.

The issue of nitrates can make some ag producers uneasy as they fear additional government restrictions. Meanwhile, many of the studies presented at Thursday’s meeting focused on discovering the optimal amount of fertilizer that producers can apply to their fields to achieve maximum production without leaching.

In addition, avoiding the overuse of fertilizer benefits farmers because it reduces fertilizer costs. The studies consider such issues as irrigated land, dryland, the timing of water in the growing season and the amount of rain or irrigation.

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

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

Dorey said across the district in the last two years, however, the average well declined about 2.4 feet. He and others who do the well checking noticed that it seems as though a lot of the wells that were near creeks were lower last year. It is unknown why that might be.

In 2018, 2019 and 2020, there were historic water levels recorded in the district, so a lot of the wells were on the upswing those years, he said.

The wells range 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 Association of Resources Districts conference earlier this year in Lincoln, said pasture and rangeland is the lowest for nitrate leaching. Then comes turf and then cropland — dryland followed by pivot — with furrow the most leaching and then some feedyards.

Powers, who is the the Research and Extension Communication specialist through the Nebraska Water Center, said balancing food production, profits and health and water impacts can be tricky.

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

Across five years that were recently studied, more than half the fields have excess irrigation taking place, Powers said. The land had soil moisture sensors across a large number of fields to determine proper irrigation amounts.

“Sometimes early in the season it is too much. Sometimes it is the whole growing season. Sometimes it’s late,” she said.

The studies provide some results that are intuitive, such as putting nitrogen on the plant when it is needed being the ideal way to go.

Irrigation is one of the largest causes of nitration, but irrigation does not make it inevitable that there will be nitration, she said.

Jeremy Milander, Bazile Groundwater Management Area Extension educator, also presented findings from the Bazile Groundwater Management Area demo site in the Upper Elkhorn NRD.

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

No action was taken on any of 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 action is not taken, except occasionally to direct staff to bring a resolution or cause of action back to the board during its regular monthly meetings.

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