At the Star Tribune, Jennifer Bjorhus reports in Manure, fertilizers overload parts of Minnesota with nitrogen, mapping project finds:
Farmers often use both commercial fertilizer and nutrient-rich manure on Minnesota’s row crops to ensure healthy doses of nitrogen for a good yield.
But that nitrogen double whammy is causing dangerous overloads in parts of rural Minnesota, particularly in regions with intensive animal agriculture, according to a national environmental group’s report out Thursday. Nitrate, a byproduct of nitrogen, taints the groundwater many Minnesotans drink and pollutes the state’s lakes and streams despite decades of work to address the problem.
The Environmental Working Group (EWG) report links nitrogen overload to the proliferation and concentration of large-scale livestock farms in Minnesota. Enforcement is hampered by regulation splintered among three state agencies, and a dearth of staff to check application rates and safeguards, the group says.
Minnesota is now home to more large, concentrated animal feeding operations than any other state except Iowa, according to the U.S. Environmental Protection Agency.
“There’s just too much manure and the landscape can’t handle it,” said EWG analyst Sarah Porter, who co-authored the study.
Readers may recall years of posts about nitrate pollution in Minnesota published on this site, from Land of nitrate-tinted water: Adrian MN only most extreme example in state's groundwater games to It's all over now, baby blue? EWG analysis concludes nitrates rising in MN drinking water .
MANURE OVERLOAD: Manure Plus Fertilizer Overwhelms Minnesota’s Land and Water is an interesting and disturbing read:
In almost all of Minnesota’s farm counties, the combination of manure plus commercial fertilizer is likely to load too much nitrogen or phosphorus or both onto crop fields, threatening drinking water and fouling the state’s iconic lakes and rivers, according to an Environmental Working Group investigation.
The problem arises from the extraordinary expansion and intensification of both livestock and crop production in the state. Since 1991, the number of large concentrated animal feeding operations, or CAFOs, in Minnesota has tripled. At the same time, fertilizer sales have increased by more than a third, fueled by the nearly 1.5 million additional acres devoted to corn.
Every year, feedlots of all sizes in the state produce nearly 50 million tons of manure – rich in nitrogen and phosphorus, the same chemicals in the more than three million tons of commercial fertilizer applied annually. Nitrogen and phosphorus are essential crop nutrients, but when they run off the fields, they can pollute drinking water sources and other bodies of water.
Using advanced geospatial techniques, EWG simulated and mapped every crop field across Minnesota likely to receive manure from nearby cattle, hog or poultry feedlots, to estimate the amount of manure applied in each county. We then added those amounts to the nitrogen and phosphorus in the fertilizer sold in the county.
The results are bad news for the state’s water quality.
- In 69 of Minnesota’s 72 agricultural counties, nitrogen from manure combined with nitrogen in fertilizer exceeded the recommendations of the Minnesota Pollution Control Agency, or MPCA, and the University of Minnesota. In 13 counties, nitrogen from the two sources surpassed the recommendations by more than half. (Table 1.) This excess nitrogen is the major cause of nitrate pollution in drinking water, which is linked to elevated rates of cancer.
- In nine counties, phosphorus pollution from manure is of high concern. These nine counties account for over half of the nearly 1.5 million acres where application of manure adds at least 10 pounds per acre more phosphorus than needed by crops. (Table 2.) Four of those counties are also among the 13 with the most excess nitrogen. Phosphorus pollution of lakes and rivers can trigger algae blooms, which are not only ugly but can also produce toxic bacteria harmful to human and animal health.
And here state representative Jeff Backer, R-Browns Valley, thought the problem was goose poop.
Speaking of goose poop, Bjorhus shares the response of one Ag Mafia member to the report:
Warren Formo, executive director of the Minnesota Agricultural Water Resource Center, which represents about two dozen major farm groups, said he thinks EWG “has a mission” and overstated the problem. He also said that “there’s a continued need to help farmers do the nitrogen balance on their farm and fine-tune their practices.”
“I would acknowledge that some farmers have areas where they could make progress,” Formo said. “But to broadly characterize it a problem for the whole county misses the fact that most farmers in that county, I think, are spot on.”
Well, that solves that.
Related posts:
- Check out MN water nitrate presentations Paul Torkelson didn't want shared with subcommittee
- Paging Rep. Torkelson: City of Fairmont issues water advisory, nitrate levels unsafe for infants
- Going with the flow: fertilizer elevated nitrate levels in Fairmont's drinking water supply
- Nitrates: Brown Co turns down MDA well testing aid because somebody might blame farmers
- Rep. Torkelson dismisses concerns about nitrates in Minnesota's drinking water
- Environmental digest: nitrates in Minnesota drinking water; beewashing; PFAS in creeks
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