Nitrogen Pools in Tropical Plantations of N<sub>2</sub>-Fixing and Non-N<sub>2</sub>-Fixing Legume Trees under Different Tree Stand Densities
Kelly Nery Bighi,
Ranieri Ribeiro Paula,
Marcos Vinícius Winckler Caldeira,
Diego Lang Burak,
Eduardo de Sá Mendonça,
Paulo Henrique de Souza,
William Macedo Delarmelina,
Fabiano de Carvalho Balieiro
Affiliations
Kelly Nery Bighi
Centro de Ciências Agrárias e Engenharias, Departamento de Ciências Florestais e da Madeira, Programa de Pós-Graduação em Ciências Florestais, Universidade Federal do Espírito Santo, Jerônimo Monteiro 29550-000, Brazil
Ranieri Ribeiro Paula
Centro de Ciências Agrárias e Engenharias, Departamento de Ciências Florestais e da Madeira, Programa de Pós-Graduação em Ciências Florestais, Universidade Federal do Espírito Santo, Jerônimo Monteiro 29550-000, Brazil
Marcos Vinícius Winckler Caldeira
Centro de Ciências Agrárias e Engenharias, Departamento de Ciências Florestais e da Madeira, Programa de Pós-Graduação em Ciências Florestais, Universidade Federal do Espírito Santo, Jerônimo Monteiro 29550-000, Brazil
Diego Lang Burak
Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Programa de Pós-Graduação em Produção Vegetal, Universidade Federal do Espírito Santo, Alegre 29500-000, Brazil
Eduardo de Sá Mendonça
Centro de Ciências Agrárias e Engenharias, Departamento de Agronomia, Programa de Pós-Graduação em Produção Vegetal, Universidade Federal do Espírito Santo, Alegre 29500-000, Brazil
Paulo Henrique de Souza
Departamento Acadêmico de Agricultura e Ambiente, Instituto Federal de Educação, Ciência e Tecnologia do Sudeste de Minas Gerais, Rio Pomba 36180-000, Brazil
William Macedo Delarmelina
Coordenadoria do Curso Técnico em Florestas, Instituto Federal de Educação, Ciência e Tecnologia do Espírito Santo, Ibatiba 29395-000, Brazil
We investigated the nitrogen pools in monocultures of legume species widely used in reforestation in Brazil that have contrasting growth and nitrogen acquisition strategies. The plantations were established with the slow-growing and N2-fixing tree Anadenanthera peregrina var. peregrina, and the fast-growing and non-fixing tree Schizolobium parahyba var. amazonicum. The measurements of N pools in the tree biomass and the soil followed standard methods and were carried out on 54 experimental plots. The N2 fixation pools were evaluated by abundance natural of 15N and the N accretion methods. The soil N content was of similar magnitude between species and stand densities. The species showed similar amounts of N in the biomass, but divergent patterns of N accumulation, as well as the 15N signature on the leaves. S. parahyba accumulated most N in the stem, while A. peregrina accumulated N in the roots and leaves. However, the N accumulation in biomass of A. peregrina stand was less constrained by environment than in S. parahyba stands. The percentage of N derived from N2 fixation in A. peregrina stands decreased with the increase of stand density. The biological N2 fixation estimates depended on the method and the response of tree species to environment.
