Understanding the role of non-exchangeable potassium in Minnesota soils
Study author(s): Daniel Kaiser
Years of study: 2024, 2025, 2026
Minnesota location(s): Various
Note: All tables and figures are available by downloading the the full report(s) below.
SUMMARY points – year 1
- Study is in the initial stages, and we have not fully collected 1 year of data.
- Soil test K significantly declined from the initial to the first sampling date in the greenhouse trials. After 7 sampling dates. STK is roughly 8-42% of the initial sol test values.
- Soil test K decline was larger during the first sampling period and has not changed much since the first sampling period
- Relationships between soil test K decline, non-exchangeable K in the soil, and K removal have not been evaluated at this time.
Summary Points – Year 2
- Data has been collected through sample time 18 which is roughly 18 months after the trial began.
- Soil test K significantly declined from the initial to the first sampling date in the greenhouse trials. After 7 sampling dates. STK is roughly 8-42% of the initial sol test values.
- Soil test K decline was larger during the first sampling period and has not changed much since the first sampling period
- There has been a significant drop in the amount of biomass produced and the daily uptake of K from the soil.
- Relationships between soil test K decline, non-exchangeable K in the soil, and K removal have not been evaluated at this time.