Department of Agriculture, Trade and Consumer Protection

Seven dairies across Wisconsin, and their local Extension educators and outreach specialists, are 2024 Nitrogen Optimization Pilot Program grant recipients! Even though the dairies are spread across the state, they’re all interested in evaluating nitrogen fertilizer rate recommendations following a manure application.

Nutrient & Pest Management Outreach Specialist Jordan Kampa said, “As Extension educators, we’ve heard from several farmers and specialists that the research around manure nutrient credits is outdated. Specifically, research and data should be updated to more accurately represent what is happening to manure nitrogen in the field and how to credit that. A group of us decided to collaborate with farmers in our respective regions (Washington, Kewaunee, Burnett, Oconto, and Chippewa counties, and two in Rock County) to establish a nitrogen rate study that includes strips with and strips without manure. We want to better understand what amount of nitrogen the manure gives us and what nitrogen fertilizer rates should be applied with manure applications. We’d also like to learn how long that manure-N credit persists. We are excited to collaborate with Dr. Steven Hall, Agricultural Water Quality Extension Specialist, to install resin lysimeters on one of the fields to measure nitrate leaching. Combining water quality measurements with a rigorous rate yield response trial will be valuable. We also don’t know much about the vulnerability of manure nitrogen vs. synthetic fertilizer nitrogen to leaching, so this project will provide us information on leaching applicable to the WIisconsin landscape. The lysimeters were installed beneath undisturbed soil in each plot and will trap nitrate in water that drains through the lysimeter. After a year, the lysimeters will be removed and analyzed in the lab. We're all very excited to be able to contribute data on a statewide scale, as we know the landscape varies across the state.”  

​Isherwood Family Farms

Isaac Isherwood of Isherwood Family Farms is a 2024 Nitrogen Optimization Pilot Program grant recipient! The project investigates the potential of Bio-Gro products to reduce nitrogen fertilizer rates and nitrate leaching on sandy soil potato production. Isaac came across Bio-Gro products while looking for humic and fulvic acid, which he heard could allow him to reduce nitrogen rates and help the plant utilize that nitrogen. The first year Isaac used it in a potato field, he said “The root mass was significantly larger just with the naked eye and both yield and quality were significantly higher. So this year, I jumped on board with almost the entire farm in potatoes.” Isherwood Family Farms partnered with Guolong Liang (Agriculture Water Quality Outreach Specialist with UW-Madison Extension) and Kevin Masarik (Groundwater Education Specialist with Extension and UW-Stevens Point) to apply for an NOPP grant with a project that utilizes lysimeters to help monitor and estimate nitrate leaching. The trial has five main treatments: “business as usual” (BAU), which is their typical nitrogen rate; a 15% reduction from BAU; 30% reduction from BAU, and no additional nitrogen fertilizer. While these treatments do not include Bio-Gro products, the fifth treatment is a 30% reduction from BAU with the addition of Bio-Gro products. When asked about the motivation behind this project, Isaac said he “hopes to get the same yield and quality with fewer nitrogen inputs.” Taking it a step further, he explained​ that it’s “okay spending more on biological products when you can reduce environmental pollution of nitrogen,” and that “it makes you feel good feeding people with the most healthy and sustainable product as possible."