When farm products are sold, some of the essential part of the soil are also marketed. If this process is continued, the soil may be eventually impoverished to the point where it cannot support high crop yields. In addition to direct soil depletion, unbalanced soil management practices may produce soil conditions that prevent or limit the uptake of certain elements by plants even though there may be enough total supply of the elements present to last hundreds or even thousands of years.
Both processes have been going on in many Utah orchards. Sale of fruit has gradually depleted the soil. Cultivation has frequently reduced the organic matter in the soil. Over-irrigation has leached out nutrients. Lime in irrigation water has made the soil more alkaline. Application of unbalanced fertilizers has helped to tie up additional essential element. Thus in many orchards productive soils have changed to less productive soils. Soil conditions are reflected in the color of leaves, the rate of tree growth, and in the yield and quality of fruits.
Thorne, D. W. and Wann, F. B., "Bulletin No. 338 - Nutrient Deficiencies in Utah Orchards" (1950). UAES Bulletins. Paper 299.