Environmental Benefits and Control of Pollution to Surface Water and Groundwater by Agroforestry Systems: a Review

Agricultural pollution consists a serious concern for environmental protection managers. Among the pollutants, nitrates, phosphoric compounds and organic pesticides from agricultural activities are the most common and hazardous to the environment and human health. Several mitigation techniques have been proposed to control these pollutants from entering aquatic systems. Agroforestry, which is the common cultivation of crops and trees, is one such mitigation technique. In the present study, the efficiency of agroforestry systems in pollutant reduction is reviewed. A search of relevant international literature was conducted using Scopus, Science Direct and Google Scholar search engines, using relevant keyword combinations for agrochemical pollution abatement with trees. More than 2000 results were found and the most relevant were selected and extensively studied, and are summarized here. From the current knowledge, it can be generally seen that tree roots in agroforestry systems are able to reduce nitrogen and phosphorus residues in soils from 20% up to 100%, have the potential to reduce pesticides leaching and runoff in considerable amounts (up to 90% for runoff), and simultaneously they provide additional benefits to the ecosystems including erosion control, improvement of soil quality and positive effects on biodiversity.