Soil Nitrogen Dynamics and Management in Agroforestry Systems for Ecological Sustainability

Abstract

AbstractThe apparent benefits of improving soil health and providing ecosystem services associated with agroforestry systems have led to the attraction of practicing agroforestry in tropical as well as temperate regions for decades. The agroforestry systems usually require low inputs in terms of capital; provide economic benefits by various forest products including fodder; reduce soil erosion; conserve water; and help to improve soil fertility by maintaining nutrients in soil. However, soil health management is unarguably one of the most important criteria for sustenance of food production and other ecosystem services in these land uses. Like other terrestrial ecosystems, maximum amount of nitrogen in soil-plant system is linked with soil and majorly in organic form. The availability of nitrogen to plants after mineralization of organic compounds is the key factor determining the production potential of agroforestry sites. In these systems specifically nitrogen-fixing tree species provide nitrogen inputs by biologically fixing nitrogen and other tree species also help in recycling nitrogen in the soil. Moreover, under the symbiotic association, nitrogen fixation can be affected due to other soil parameters like soil pH, the toxicity of aluminum and manganese, deficiency of nutrients like calcium, magnesium and phosphorus, water stress, soil texture and type. The contribution of agroforestry land uses toward sustainable economic production is often constrained owing to these limitations related to nitrogen cycling. Since the agroforestry systems extract more nitrogen from soil as compared to conventional agriculture fields, balance in nitrogen input and loses is required to maintain ecological sustainability of these systems. Keeping these facts into consideration, the proposed chapter aims to manifest dynamics of nitrogen in agroforestry systems and present a conclusive outlook on practices followed worldwide for efficient nitrogen management in different agroforestry land use patterns on the basis of available literature.KeywordsAgroforestry systemsSoilNitrogenSustainability