Susan Winsor

October 1, 2007

8 Min Read

Craig Recker won a yield contest without a speck of commercial fertilizer. His New Vienna, IA, neighbors couldn't believe that manure and alfalfa credits alone tipped the scales. Although his yield monitor maxxed out, his corn stalk nitrate test hit a new low, indicating his crop had just enough nitrogen (N) from legumes and manure to deliver the prize, and no more. A stalk nitrate test told him how much N remained unused in his corn tissue at the end of the growing season; money in the bank for the next crop.

Located a stone's throw from where the movie “Field of Dreams” was filmed, his Hewitt Creek, IA, watershed is cleaner than it's been in a long time. Farmers, not government regulators, are cleaning up their watersheds. Through Iowa Extension's innovative Performance-Based Environmental Management program, local farmers set water quality goals, incentives and priorities for their watersheds.

The 23,000-acre Hewitt Creek Watershed has 82 farm operators tilling 19,181 acres of highly erodible Fayette-Downs cropland. The livestock-intensive watershed landed on the Iowa DNR list of impaired waters due to low populations of aquatic macro-invertebrates and fish, and high levels of N, phosphorus (P) and sediment.

Using the Extension program, farmers there brainstorm solutions and strategies, with technical assistance on tap as needed. The solutions end up being specific to each farm and each watershed, rather than dictated from a state capitol or Washington, D.C.

“Farmers are anxious to preserve water quality; they just need the right information,” says John Rodecap, who leads farmer-directed watershed projects for Iowa State University Extension. “The more info they get, the more keen they are to do it. It's a win-win deal. It helps their bottom line and it helps their watershed.”

He believes that “the problem should be owned and solved locally. The very people who can impact water quality lack the technical information and involvement in the problem,” he says.

No one wants another meeting to attend, “but when farmers see their name on the watershed plat map and realize that they are each a part of it, a common goal emerges and they take ownership,” says Tim Recker, an Arlington, IA, farmer who participated in another Performance-Based Water Quality effort in his Maquoketa Watershed 10 years ago. (He is not related to Craig Recker.)

What paid off the best environmentally on his farm were buffer strips, contour farming and on-farm N demonstrations. “I learned that 110 units of N/acre was all I needed to get the best bang for my buck,” he says. “The fall Corn Stalk Nitrate Test showed residual N in my crop after harvest.”

Recker has assisted watershed groups in testing a wood chip denitrification biofilters in Butler and Buchanan county water tile outlets. They reduce nitrate flows into creeks by 50-90%. They are an alternative to constructed wetlands, which occupy a lot more space. The 1-sq.-ft. flow control box to pressurize the biofilter costs about $1,500 for each outlet that drains 40-80 acres and requires little maintenance. “You can install it anywhere there's an outlet into a creek,” he explains.

Fifty miles southeast of Recker lies the Hewitt Creek Watershed, near the Dyersville, IA, field of dreams made popular in the movie. Participating farmers there learned how to inventory manure-supplied nutrients, and the amount of N in their Stalk Nitrate Test dropped by 26%, indicating that they had inadequately credited their“liquid gold” for nutrients.

By knowing how much excess N was potentially available to their crops, farmers reduced their need for commercial N. Farmers in the watershed also prevented nearly 600 tons of soil from moving into the stream annually — an 18% reduction. They reduced the amount of P reaching their stream by 1,200 lbs. annually, or 12%.

“I've learned that 3,500 gal. of hog manure can produce 200-bu. corn using no-till,” one participant commented.

Added another: “One guy does something that works, others will do it, too.” This neighbor-to-neighbor grassroots approach costs pennies on the dollar compared to federal conservation programs,says Craig Recker.

The Hewitt Creek Watershed project was started with $90,000 over three years from the Iowa Farm Bureau. This covered some of the cost for computer modeling farms' P Index, Soil Conditioning Index, Corn Stalk Nitrate Test and performance improvement incentives paid to watershed cooperators.

The watershed's farmers set a goal of reducing sediment delivery to Hewitt Creek. In the program's first year, 23 participating farmers were offered $400/farm to seed more than 17 miles of grass waterways. These incentives were developed by the watershed farmer group. Farmers incentives were 10¢/ft. of waterway, anchoring an estimated 3,482 tons of soil annually from the highly erodible landscape.

Intensive livestock production and water quality indicators also prompted P-Index calculations on over 300 fields (7,900 acres). Tools for lowering P Indexes include extending rotations, conversion to grazing, converting to no-till, planting more waterways, in-field and edge-of-field buffers, contour planting and attentive manure and commercial P fertilizer management. Farmers learned how to calibrate their manure spreaders and test soils to identify which fields most need the nutrients.

About one-third of watershed farmers hadn't tested for P, another third tested but their records are retained by the fertilizer dealer and less than one-third actively managed their farm P needs. Sixteen cooperators chose the $300 incentive to grid-sample.

Each watershed faces different water quality issues and has the autonomy to set its own goals and tactics. In Butler County, IA, two neighboring Iowa watersheds encompassing 30,000 acres landed on the EPA's 303(d) list of impaired waters. The voluntary Coldwater/Palmer Creek Watershed Association's 37 farmers set goals of:“Refining N management while enhancing net farm income and eventually having the watershed removed from the EPA list.”

They learned how to tally their manure's nutrient content and match its application to the most suitable fields. Besides improving water quality, the practice has substantially reduced their N costs.

Twenty-three watershed growers collected their corn stalks for N and a variety of other on-farm N management practices. The test tells farmers how much N remains unused in the corn tissue after the growing season.

The local Rockford FFA chapter that gathered corn stalks for testing has also learned valuable lessons about refining N management and environmental stewardship for the day that they make on-farm decisions.

The first year of the Coldwater/Palmer Creek program, participating farmers each earned between $400 and $1,876 in incentives for on-farm practices that reduced nutrient and sediment loss. More importantly, they learned practices specific to their farms that reduced nitrates entering the watershed while improving net farm income.

The Coldwater/Palmer Watershed's program was partially funded by the Iowa Corn Growers Association ($90,000 over three years). This seed money earned the watershed an additional $311,594 from the Iowa Watershed Improvement Fund.

As the 23,000-acre Hewitt Creek Watershed project moves into its third year, Dyersville, IA, farmer John Rahe reflects on the two streams he's neighbored for 54 years. He sees more bald eagles, blue herons, frogs and swallows living off these waters than he did even as a child. “It's been along time since I saw kids have a reason to drop fishing poles in our streams. We're off to a good start. This reflection of abundant stream life has resulted from neighbors sharing what works,” he told local farmers at a watershed demonstration field day.

He and his neighbors compared notes on grid sampling, cover crops, manure spreader calibrations, soil testing and lots of other daily decisions that cumulatively reduce water levels of nitrates,P and sediment.

One hundred miles to the northwest, Dougherty, IA, farmer David Muth is vice president of the Coldwater/Palmer Creek Watershed Association. He has increased both farm profits and local water quality while “doing two things that many feel are not good for the land: One is continuous corn and the other is spreading hog manure every year,” he says.

Computer modeling technology has enabled him to verify that he has reduced his soil erosion, and his P Index is at the lower end of average. He injects his manure in colder temperatures, has reduced his tillage, feeds his hogs phytates to increase their P utilization and began grid soil sampling. These management changes plus the monitoring tell him he's better off on both counts (N and P).

“This shows that we can be environmentally friendly and still not increase our cost of doing business,” Muth says. “We can regulate our farms more effectively, and less expensively, than can Washington.”

Tools of the trade

Each participating field, farm and watershed measures its baseline index using these three yardsticks:

  • The Phosphorus (P) Index measures the risk of P moving from fields to water bodies. Contributing to this are soil loss, soil test P values, rate and method of P application, field distance to water and tile drainage.

  • The Soil Conditioning Index predicts the effect of crop rotations, cover crops and tillage systems on soil organic matter. It considers the amount of organic material returned to the soil, the effect of tillage operations and erosion.

  • The Corn Stalk Nitrate Test measures the amount of N left in the lower corn stalks at the end of the season.

On-farm sampling practices

Farmers in the Lower Coldwater Creek/Palmer Creek and Hewitt Creek watersheds chose from the following list of performance incentives to manage excessive nitrogen (N), sediment and phosphorus (P) flow into their streams without compromising farm income. This is a partial list:

  • Reducing the farm's risk of P loss.

  • Controlling sediment loss through tillage practices, fall cover crops, rotations and conservation structures and practices.

  • Installing new grass waterways.

  • Grid sampling.

  • On-farm comparison of tillage alternatives with yield results.

  • Stalk Nitrate Test levels below a threshold indicating the crop did not receive excess nutrients. The test tells how much N is left in the stalk after harvest to assess proper N application rate.

  • Late-spring nitrate test levels indicating proper N levels before rapid growth stage.

  • P Index computer modeling to identify P movement from their farm.

  • Manure spreader calibration.

  • Manure analysis to determine available N, P and potassium.

  • Seed headlands or other buffers along streams.

  • Cover crop seeding after corn silage and soybean harvest.

About the Author(s)

Susan Winsor

Before joining Corn and Soybean Digest, Susan was an agricultural magazine editor for Miller Publishing, a newspaper reporter for Gannett newspapers and Manager, Marketing Publications for Cenex/Land O’Lakes Ag Services. She graduated from Colorado State University with a Bachelor of Science degree in Agricultural Journalism.

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