Lorenzo A. Richards

Lorenzo Adolph Richards (April 24, 1904 – March 12, 1993) or known as Ren was one of the 20th century’s most influential minds in the field of soil physics.

Lorenzo A. Richards was born on April 24, 1904, in the town of Fielding, Utah, and received a B.S. and M.A. degree in Physics from Utah State University. His PhD thesis, completed at Cornell University in 1931 and entitled Capillary conduction of liquids through porous mediums, was arguably one of the best known in the field of soil physics.

Following his time at Cornell, and a brief stint at Iowa State University, he spent the most part of his working life engaged in soil physics research at the United States Department of Agriculture Salinity Laboratory in Riverside, California.

His thesis represented the first decisive progress beyond the work of Edgar Buckingham in the extension of Darcy's law to describe water movement in unsaturated soils. In this research, Richards described a partial differential equation, now commonly known by as the Richards equation.

One of his key interests was the energy status of soil water, and he led the way in developing new and improved methods of measuring soil water potential. Early in his career, Richards recognised the importance of capillary potential to plant-soil relations, and described the principles, construction and operation of the tensiometer. Richards also proposed the tension plate apparatus for determining capillary potential in soil. The tensiometer was developed from the idea of using a semi-permeable, porous ceramic material to balance a pressure potential against a matric potential; once equilibrium had established, the matric potential of the soil could be determined by balancing the pressure potential.

...
Wikipedia