DYNAMICS OF TREE-CROP INTERFACE IN RELATION TO THEIR INFLUENCE ON MICROCLIMATIC CHANGES?A REVIEW

Integration of trees with crops adds a significant element of biological diversity to agronomic systems and promotes sustainable, protective and productive land use. The biological interactions between the major components i.e., trees and crops are of primary importance ana introduce challenges and complexities not present in sole cropping. Specifically, it must be demonstrated that satisfactory growth and yields of both trees and crops can be achieved in the microenvironment of the agroforestry land-use system that varies considerably with time. Compared to an open environment, the modified microclimate under trees will have reduced solar radiation, a lowered red:far-red light ratio, a more moderate temperature regime, higher humidity, lower rates of evapo-transpiration and higher soil moisture levels. All of these factors will change as a function of tree development and tree management practices. The spacing arrangement chosen for trees will also be a factor in determining how rapidly the changes come into play. During the establishment phase, tree shade will be minimal and have little significant effect on the understory companion crops. However, as the trees grow, the changes in the microclimate will become more pronounced, which might strongly affect the growth and compatibility of the understory companion crop.