Nitrogen (N) fertilizer is commonly applied to increase productivity of forest plantations, and the extent and intensity of forest fertilizer use could increase in the future as a way of enhancing forest productivity to meet demands for both traditional products and emerging markets for energy and biomaterials. While much of the applied N remains in the soilplant system, there are concerns about leaching losses and effects on surface water quality. However, understanding the fate of fertilizer N and its potential environmental impacts is particularly complex due to a wide range of abiotic and biotic factors affecting its forms and movement.
There have been many N cycling studies in pine plantations, but relatively few have comprehensively addressed links between terrestrial processes and the ultimate fate of fertilizer N. While a variety of hydrologic and nutrient cycling models have been applied to simulate N fate and transport at different spatial and temporal scales in agricultural and forested ecosystems, available field studies are generally inadequate to validate those model predictions. Experiments are needed to validate model predictions on the transport and fate of N through the soil and water network. Once validated, models can be used in the development of general fertilizer guidelines for resource managers and can help document how fertilizer can be safely and effectively used at stand and landscape scales.