Some Factors That Influence Nitrate Formation in Acid Soils

Current insights into the autotrophic thaumarchaeal ammonia oxidation in acidic soils

“…However, these widely-observed phenomena were entirely attributed to some purely chemical agents, before the discovery of bacterial ammonia oxidizers in actively nitrifying soils (Winogradsky, 1890). Although the responsible microorganisms and relevant mechanisms still remained elusive, the positive correlations between aerobic bacterial numbers and nitrate concentrations began to be noticed (Fred and Graul, 1916;Noyes and Conner, 1919). These early discoveries paved the way for more convincing studies confirming that nitrification was a universal phenomenon in a wide range of acidic soils, and stimulated scientific interests to identify the responsible nitrifiers in soils (De Boer and Kowalchuk, 2001).…”

A Study of the Factors Influencing the Efficiency of Different Forms of Nitrogen as Related to Soil Type and Cropping System in the Atlantic Coastal Plain Region

“…organic matter, colloidal clay and zeolites, and microorganisms as well, may, in many instances, outweigh the influence of either an unfavorable OH-or H-ion concentration. This view is supported by the work of Fred and Graul (30) For mineral soils the optimum reaction appears to be at about pH 7.0; although maximum values of OH-ion concentration of 13.0 and minimum values of pH 5. 4 have been recorded.…”

Nitrification in Dutch heathland soils

“…Since the beginning of this century, soil scientists have occasionally reported the occurrence of nitrate production in acid soils (Fred and Graul 1916;Kaila 1954;Weber and Gainey 1962;Gerlach 1973). Yet, not much attention was paid to the production of nitrate in acid soils until it became evident that this process may contribute to environmental problems: -(1) Acidification.…”