Improving the Reliability of Soil Potassium Testing and Recommendations
IPNI-2013-USA-IA20
RESEARCH JUSTIFICATION There is a long history of potassium (K) soil testing and management in Iowa and the North-Central Region. A period of especially extensive and diverse research extended from the late 1950s to the middle 1970s, especially with work in Illinois, Indiana, and Iowa but also in other states. During these years there was a great deal of basic K chemistry and mineralogy studies and also field applied research focusing on soil K testing and crop response to K fertilization. Read more
Interpretive Summary
This project is in its final stages and the Potassium (K) Fellow is completing data management and statistical analyses. The study has two major objectives. The first objective is to study the relationships among soil-test K, non-exchangeable K, and relevant properties of soils of the western humid Corn-Belt (those with large acreages dedicated to corn and soybean production). Chemical and mineralogical analyses were completed for 23 soils.
The goal of this project is to improve soil testing for potassium (K) and the assessment of crop K fertilization needs. There is much more uncertainty in the use of soil testing for K than for phosphorus (P). For example, we hypothesize that processes involving the so-called non-exchangeable soil K pool and the residue K pools have much more important impacts on soil-test K levels variation between two crops and crop response to K fertilization than is generally recognized.
Updates & Reports
| 2013 | Project Description |
Project Leader
Antonio Mallarino, Iowa State University
Project Cooperators
Ryan Oltmans
Michael Thompson
IPNI Staff
Location
Americas \ Northern America \ USA \ Iowa