In the spring of 1903, we commenced at the Utah Experiment Station a series of experiments, the purpose of which was to study the development and movement of nitrates in irrigated soil. The work was so outlined that it should give some very definite results, both as to the influence of water and the plant, upon the nitric nitrogen content of the soil.
Stewart, Robert and Greaves, J. E., "Bulletin No. 114 - The Movement of Nitric Nitrogen in Soil and its Relation to "Nitrogen Fixation"" (1911). UAES Bulletins. Paper 65.