Only within the last few years has the question of commercial fertilizers been worthy of serious consideration in Utah. It has been considered that commercial fertilizers were unnecessary in Utah (1) because arid soils retain their virgin fertility much longer than soils in the humid region which are subject to continual leaching by heavy precipitation, (2) because livestock have always predominated in Utah's agriculture due to the vast areas adapted only to range purposes and livestock means manure to maintain fertility, and (3) because alfalfa, our principal feed crop, is also one of the best plants for gathering nitrogen from the air, which is added to the soil in the manure and thus tends constantly to build up fertility. However, it now seems that for some particular fields there is an inadequate supply of manure, and in a few cases the manure is hardly adequate in itself to maintain the fertility of the soil; so an interest is now being developed in commercial fertilizers.
Pittman, D. W. and Burnham, Clarence, "Bulletin No. 233 - Observations on the Use of Commercial Fertilizers on the Arid Soils of Utah" (1932). UAES Bulletins. Paper 190.