Submitted to: Communications in Soil Science and Plant Analysis
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/31/2007
Publication Date: 3/1/2008
Citation: Goldberg, S.R., Scalera, E., Adamo, P. 2008. Molybdenum adsorption by volcanic italian soils. Communications in Soil Science and Plant Analysis. Vol 39:693-706 Interpretive Summary: Molybdenum is a specifically adsorbing anion that can be detrimental to animals at elevated levels. Detrimental levels can occur from ingestion of forage plants grown on soils irrigated with waters containing high concentrations of molybdenum. A better understanding of the adsorption behavior of molybdenum is necessary. Adsorption of molybdenum by 5 Italian andisols was evaluated and predicted using a chemical model and easily measured soil chemical characteristics. Our results will benefit scientists who are developing models of molybdenum movement in soils. The results can be used to improve predictions of molybdenum behavior in soils and thus aid action and regulatory agencies in the management of soils and waters which contain elevated concentrations of molybdenum.
Technical Abstract: Molybdenum adsorption behavior was investigated on five volcanic soils from Italy, characterized by different degrees of development. Molybdenum adsorption exhibited a maximum near pH 4 to 5 and decreased with increasing solution pH above 5. The constant capacitance model was able to fit molybdenum adsorption on the soils as a function of solution pH. A general regression model previously developed by Goldberg et al. (2002) was used to predict Mo surface complexation constants from easily measured soil chemical parameters: cation exchange capacity, organic carbon content, inorganic carbon content, and iron oxide content. The predicted Mo surface complexation constants were used in the constant capacitance model to predict Mo adsorption on the soils thereby providing a completely independent evaluation of the ability of the model to describe Mo adsorption. The prediction equations developed from a set of soils primarily from California were able to predict Mo adsorption on four out of five soils from Italy. This result suggests wide applicability of the model prediction equations developed previously, for describing Mo adsorption by soils of diverse mineralogy and parent material.