In the following investigation was determinated the contribution of the silvopastoral a system (SSP) in high density with Leucaena leucocephala edaphic and foliar nitrogen exposure, considering the symbiotic relationship with Rhizobium. The time of establishment and it´s structure, and in this way provide information in the different silvopastoriles option to the rancher producer involved in livestock conversion processes in inter Andean zones of Valle del Cauca and Risaralda, and even show those agroforestry systems as Ectechnology, that allows establish a sustainable productive system. Two experimental places were selected to make the quantification of the edaphic and foliar nitrogen in the SSP, with Leucaena: the Tarambuli farm, located in Balboa-Risaralda, in which were studied the nitrogen´s changes, during the first months (7 months) and the Lucerna farm, located in Buga, Valle del Cauca in which it hat systems with different time of establishment 7, 16 and 21 years. The Tarambuli system was located in a portion of land 22mx19,5m, considering three blocks and two treatments, determinated by the inoculation of the Leucaena´s seeds, with the Febiol productos, the germination process in the seedbed during 13 week, and then take them to the field to start all the process, samples were taken between week 8 and week 28 in the established system.