Allelochemicals are compounds released by one plant or plant residues that may have a negative or positive effect on other plant. The importance of allelopathy was extensively explored during the past three decades, with the work concentrating in the extraction and identification of the chemicals, and demonstration of activity in petry dish experiments. These compounds interact in the soil environment similarly as herbicides and are subject to processes of degradation such as microbial degradation, oxidation, and photolysis, and processes of removal or transfer, such as volatilization and adsorption. The objective of this review was to access the fate of allelochemicals in the soil environment to help to find strategies to increase its activity. The activity of allelochemical is limited in time (because of slow release from the donor material) and in space (because of the interaction with the environment). Demonstration of allelopathy should include the fate of the proposed chemical in the soil environment, presenting studies of degradation and removal processes.
adsorption; allelopathy; oxidation; photolysis; plant interference; volatilization