The mission of the K research team at Purdue University is to better understand the soil, plant, and management factors that impact plant-available K in soil and K nutrition of crop plants, and to disseminate this information to the public and the scientific community in a timely and relevant manner.


Dr. Sylvie M. Brouder

Improving soil K management for corn-soybean rotations requires a better understanding of spatial and temporal factors governing root-zone K availability and the physiology of plant K need. Failures of current soil and tissue testing and recommendation protocols stem from test limitations and a black-box approach to relating yield to K fertility management. The goal of my program is to understand the plant and soil characteristics, mechanisms and processes that govern plant K status and incorporate these factors into soil fertility recommendations.

James J. Camberato

My past research efforts with K have involved its availability to cotton on sandy soils of the Atlantic coastal plain. Studies have examined the accumulation and distribution of K in the layered soils of this region and the contribution of subsoil accumulations to K availability. Most recently I have conducted K response experiments with cotton cultivars spanning nearly a century of development, to determine if K requirements have changed with cultivar improvement. My research in Indiana will focus on optimizing K availability to agronomic crops by manipulating soil K pools and identification of the most efficient methods of fertilization.

Dr. Brad C. Joern

Our laboratory's primary effort related to potassium is to better understand the role of nonexchangeable, or fixed, K as a plant nutrient resource. Nonexchangeable K can be a significant source of K for plants and we have developed a modified sodium tetraphenylboron soil test to more accurately assess plant-available solution, exchangeable, and nonexchangeable K pools. We are also interested in the impacts of anhydrous ammonia (and other N sources) on plant-available K in soils, and we work with plant physiologists to determine the physiological and molecular response(s) of plants to K nutrition. By improving our plant-available soil test K methods and increasing our knowledge of how plants respond to K stress, we hope to develop more profitable K management systems for crop and livestock producers.

Dr. Jeffrey J. Volenec

The goal of our potassium research is to understand how K nutrition alters physiological and biochemical processes in alfalfa roots that ultimately improve alfalfa persistence and growth. This goal is achieved using detailed field, greenhouse, and laboratory studies that examine many traits of alfalfa ranging from yield and the components of yield to expression of K-regulated genes. Coupled with a detail analysis of soil K chemistry, we hope to develop improved K-management systems for alfalfa and other forage legumes that enhance profitability for farmers.

Dr. Tony J. Vyn

My cropping systems team is investigating the response of both corn and soybean to potassium (K) fertilizer placement depth and application timing in conservation tillage and high yield environments. Our goals are (a) to better understand the crop and soil dynamics associated with deep band (ranging from 15- to 30-cm depths) and (or) starter band versus broadcast placement on soils with various levels of soil nutrient stratification resulting from a history of conservation tillage, (b) to determine the extent to which crop seed quality can be improved, and within-field spatial variability be reduced, by K management strategies, and (c) to develop better recommendations on K fertilizer management for conservation-till farmers in the Eastern Corn Belt.