Division of Extension
Extension specialists and educators provide timely resources and information to help Wisconsin crop producers and their agricultural consultants manage crops efficiently and profitably.
Decades of university research suggest something surprising: for most fields, annual soil testing provides little added value. The real question is not how often you can test but how often you can gather information that guides a management decision.
Andrew Stammer reviews soil test data collected from DATCP-certified Wisconsin soil testing laboratories between 2020 and 2024.
Rianne Wagner discusses phosphorus fertilizer enhancement products and whether they add value or just cost.
Chris Bandura shares early results from a statewide project evaluating nutrient uptake and removal in alfalfa fields across Wisconsin, with a focus on improving fertilizer recommendations and potassium management.
Every year, across Wisconsin and the Midwest, thousands of plant tissue samples are pulled from corn and soybean fields. They are bagged, labeled and shipped to the lab, and then a report comes back with results. And too often, that is where the story ends. Plant tissue testing is not just about measuring nutrients. It is about making decisions.
Explore 2025 Nitrogen Optimization Pilot Program activities, projects, and program details.
Chris Bandura explores Wisconsin research on berseem clover and other legume cover crops, how nitrogen credits are calculated, and what farmers should consider when using cover crops to support crop nutrition and improve nitrogen use efficiency.
Dr. Matt Ruark discusses what’s changing in Wisconsin nutrient management guidelines for corn and soybeans.
Dr. Jingyi Huang explores emerging sensor technologies that measure soil nitrate, moisture, and temperature to help farmers better understand nitrogen availability, nutrient losses, and crop needs throughout the growing season.
Dr. Natasha Rayne shares UW–Madison research exploring manure nitrogen availability, soil nitrate testing, crop sensing technologies, and environmental factors that influence in‑season nitrogen decisions.
Manure is valuable but applying it accurately is tricky because it does not have a guaranteed analysis like commercial fertilizers. Sampling and testing will maximize the economic value of your manure. But, when is the best time to sample manure?
