Agroforestry is a land - use system that involves deliberate retention,
introduction, or a mixture of trees or other woody perennials in
crop/animal production systems to benefit from the resultant ecological
and economic interactions. Nitrogen and carbon is an essential nutrient
element for organisms and is a key factor controlling plant growth and
soil microbial activity in most terrestrial ecosystems. In general,
plant growth and microbial activity are limited by low availability of N
and C, especially in terrestrial ecosystems where low temperature
restricts N and C mineralization and where most N is trapped in soil
organic forms that are unavailable to plants. Agroforestry is helpful to
stimulate these ecosystem services. Therefore, knowledge of N retention
and turnover processes in soil and the factors controlling these
processes are very important to better understand terrestrial N and C
cycle and its potential response to global change.