ABSTRACT
Mineral nutrition-along with availability of water and cultivar; control of diseases, insects, and weeds; and socioeconomic conditions of the farmer-plays an important role in increasing crop productivity. Nutrient concentrations in soil solution have been of interest for many decades as indicators of soil fertility in agriculture (Hoagland et al., 1920). Mineral nutrition refers to the supply, availability, absorption, translocation, and utilization of inorganically formed elements for growth and development of crop plants. During the 20th century (1950 to 1990), grain yields of cereals (wheat, corn, and rice) tripled worldwide. Wheat yields in India, for example, increased by nearly 400% from 1960 to 1985, and yields of rice in Indonesia and China more than doubled. The vastly increased production resulted from high-yielding varieties, improved irrigation facilities, and use of chemical fertilizers, especially nitrogen. The results were significant in Asia and Latin America, where the term green revolution was used to describe the process (Brady and Weil, 2002). The increase in productivity of annual crops with the application of fertilizers and lime in the Brazilian cerrado (savanna) region during the 1970s and 1980s is another example of 20th-century expansion of the agricultural frontier in acid soils (Borlaug and Dowswell, 1997).
