Water quality: Important for farmers to manage nutrients and keep out of water

Gloria Hafemeister
When water overflows the banks of creeks and rivers and moves onto farm fields it takes with it nutrients from those fields when it recedes.

WISCONSIN DELLS - Getting the most out of your fertilizer investment can be challenging, especially in times of low grain prices and compounded by wet conditions like many have encountered in recent years. And while farmers are trying to zero in on the most efficient fertility program for profitability, state agencies are watching the evolution of nutrient management practices with the goal of reducing nitrogen and phosphorus transport to surface waters and groundwater.    

During the recent annual Discovery Farms conference in Wisconsin Dells, the topic of water quality was covered extensively.     

With an audience filled with several hundred farmers and crop advisors, experts in water quality research pointed to the realities of well and lake contamination and the importance of managing nitrogen and nutrients in a way that these nutrients do not end up in the water.        

Farmers agree that this is a good thing.     

Tony Peirick, one of the organizers of the Dodge County Healthy Soils – Healthy Waters group says farmers have a lot to learn about nitrogen use and efficiency and about ways to protect wells, lakes and streams from runoff.     

While more and more farmers these days are working with crop consultants to test soils, monitor fertilizer use and restrict spreading at certain times and in particular places, Peirick says there are still many farmers out there who just rely on the fertilizer salesmen to make recommendations and who are actually using more fertilizer (particularly nitrogen) than will benefit the crop.     

Kevin Masarik of the University of Wisconsin, Stevens Point, shared information on research in the central sands area of the state.      

He points out that Wisconsin’s landscape varies tremendously in soils, bedrock and land use. The intersection of sandy soils and agricultural land use requires careful and intentional management.         

He states, “Nitroten is a year-round problem – not just in the growing season.”   

Geology and soil influence how quickly water moves and nitrates have been found to be the widest spread contaminant.      

He also mentions, “If the source of nitrate found in a well is a farm, that water will also likely have chemicals in it. If the source is a septic system it will also have contaminants but they will be things like caffeine, e-coli and others.”     

He suggests, “In some areas, (where there is well contamination) land use practices alone may not help prevent leaching. Farmers in these areas will need a combination of strategies including a look at the well itself.”       

He points to the need to look at soil type and weather conditions when applying nitrogen, even when it is done according to the nutrient management plan. Soil temperature also plays a role. There is very little leaching when cold temperatures inhibit mineralization.         

“Increased rainfall and warmer soils in the spring add to the problem. Encouraging cover crops and diversification of crop rotations will help,” he says.   

Two-thirds of Wisconsin residents rely on groundwater for drinking water. There are several studies happening in the state to provide more information about the current state of water quality and the impacts from land management. New data from a groundwater study in southwestern Wisconsin shows septic systems are contributing to water quality problems for rural residents.     

A panel involved in that study shared their findings with conference attendees, pointing to ways farmers can help and also talking about ways wells can be monitored to make sure they are properly installed and maintained.   

Panelists included Lynda Schweikert, Grant County Conservation, Sanitation and Zoning Department; Joel Stokdyk, USGS Laboratory for Infectious Disease and the Environment; Maureen Muldoon, Wisconsin Geological and Natural History Survey; and Jim Winn, a farmer with the Lafayette Ag Stewardship Alliance.       

Winn pointed out, “I got involved because as farmers we want to be good stewards of the land and be part of the solution.  We looked at what we in southwest Wisconsin can do better.”        

The Southwestern Wisconsin Groundwater and Geology (SWIGG) study started in 2018 and has tested hundreds of private wells in Grant, Iowa and Lafayette counties.       

The study's first phase tested wells for bacteria or nitrates, a compound linked to a variety of health problems.    

The first round of source sampling in April found 32 out of 35 wells had fecal contamination. Thirty wells had human microbes, 17 wells had cattle microbes and five had pig microbes.      

Schweikert said the test results are anonymous so officials can't be sure what kind of septic system well owners have. But she said homeowners in rural parts of the county likely have private septic systems.      

"The downfall of our septic systems is it’s out of sight, out of mind," Schweikert said. "Flush the toilet in the house, the waste leaves the house and doesn't backup into our house so we’re convinced that it’s working fine."       

She recommends residents have a plumber check their septic systems every three years, as well as regularly cleaning filters and addressing soil compaction or ponding in their drain field.       

Now in the second phase of the SWIGG study, randomly selected wells that were found to be contaminated with fecal matter in the first phase, were analyzed for specific viruses and bacteria. Of those wells selected, the majority had microbes consistent with human fecal matter.      

Schweikert said, “Seeing the human fecal contamination being the majority of the last two testings, we are looking at our (septic system) maintenance program and making sure that everyone is following the rules.”       

As for farming practices, she said if contamination is found farmers need to look at alternative manure handling methods or consider cover crops and other management practices but she also suggested there is a need to find ways to fund these efforts.      

While farmers know there is a need to monitor manure and fertilizer management practices to protect the water, they are also concerned that too often animal agriculture gets the blame for water quality problems and the data from testing indicates that in many cases rural systems are equally to blame.    

Meanwhile, testing and monitoring practices continue and throughout the state farmer-led land and water management groups are working to learn ways to protect wells, lakes and streams by improving farming practices. Discovery Farms also continues to do on-farm monitoring and to learn better ways to deal with the issue according to the particular soil conditions where the farm is located.