Marion LeRoy Jackson was a renowned soil scientist known for his work in soil mineralogy and chemical analysis. He was associated with the University of Wisconsin-Madison, where he conducted significant research on soil colloids and mineralogy. His work includes developing methods for soil mineral characterization, such as X-ray diffraction techniques and the analysis of soil clays. The text "Soil Chemical Analysis" is recognized as a key instructional manual for graduate students and a guide for research in soil chemistry, physical chemistry, and soil fertility.