ABSTRACT
I. Introduction.....................................................................................................25 II. Bioavailability of Trace Elements as Related to Root-Induced
Accumulation/Depletion of Ionic Species in the Rhizosphere......................26 III. Bioavailability of Trace Elements as Related to Root-Induced
Acidification/Alkalinization of the Rhizosphere............................................30 IV. Bioavailability of Trace Elements as Related to Root-Induced
Oxidation/Reduction in the Rhizosphere .......................................................32 V. Bioavailability of Trace Elements as Related to Root-Induced
Complexation/Chelation in the Rhizosphere .................................................33 VI. Conclusions.....................................................................................................36 References................................................................................................................37
Predicting the bioavailability of trace elements to plants is a major agricultural and environmental issue. Indeed, plants are the prime entry point for trace elements in the food chain. On the one hand, for trace elements that are essential micronutrients for plants, animals, and human beings, the need arises for ensuring adequate levels in agricultural products. Indeed, deficiencies of micronutrients are fairly widespread in various types of soils worldwide. On the other hand, as a consequence of human activities, concentrations of potentially toxic trace elements tend to build up in some environments and ultimately cause contamination of the food chain. Similarly as described for major nutrients by researchers such as Clarkson
