Submitted to: Plant and Soil
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 20, 1997
Publication Date: N/A
Technical Abstract: Boron is an essential micronutrient for plants, but the range between deficient and toxic B concentration is smaller than for any other nutrient element. Plants respond only to the activity of B in soil solution and not to B adsorbed on soil constituents. Soil factors affecting availability of B to plants are: pH, texture, moisture, and temperature. Boron adsorbing surfaces in soils are: aluminium and iron oxides, magnesium hydroxide, clay minerals, calcium carbonate, and organic matter. Boron adsorption reactions can be described empirically using the Langmuir adsorption isotherm equation, the Freundlich adsorption isotherm equation, and the phenomenological Keren model. Chemical models such as the constant capacitance model, the triple layer model, and the Stern VSC-VSP model can describe B adsorption over changing conditions of solution pH and B concentration. Boron desorption reactions often exhibit hysteresis. The rate of B desorption can be described using the first order rate equation, the Elovich reaction rate equation, and the power function equation.