Acessibilidade / Reportar erro

Nutrient input through litter in a degraded area revegetated with legume trees

The aim of this work was to evaluate the nutrient input through litterfall, in one area degraded by soil remotion, replanted with ten-year-old nitrogen-fixing legume trees Acacia auriculiformis (acácia), Gliricidia sepium (gliricídia), and Mimosa caesalpiniifolia (sabiá) and another neighbor area with a secondary growth Atlantic forest ("capoeira") fragment. The experiment was carried out at the Embrapa - Agrobiologia research station, Km 47, Seropédica, State of Rio de Janeiro, Brazil. The litterfall was quantified in litter traps with an area of 0.25 m²; nutrients and polyphenols of the litter components were determined. The litterfall quantity varied according to the legume tree species, reaching a dry mass (DM) of 5.7 Mg ha-1 year-1 where gliricídia predominated, and 11.2 Mg ha-1 year-1 under sabiá land cover including some litterfall from acácia. The litterfall production under "capoeira" was 9.2 Mg ha-1 year-1 . The gliricídia litterfall showed the lowest polyphenol concentration and was richest in nutrients (N, P, Ca, and Mg), representing the most favorable litter quality for decomposition processes. The nutrient input was correlated with the amount of litterfall. The annual nutrient input in kg ha-1 year-1 ranged from 130-170 for N, 4.9-7.9 for P, 24-31 for K, 150-190 for Ca, and 29-40 for Mg. These values are similar or superior to those observed in "capoeira" which are 140 for N, 4.9 for P, 110 for Ca, and 31.7 for Mg, except for 63 for K. Land revegetation with legume trees added large quantities of organic matter and N to the system through litterfall in a relatively short time, improving nutrient cycling and the rehabilitation process.

biological nitrogen fixation; decomposition; Atlantic Forest; soil reclamation


Sociedade Brasileira de Ciência do Solo Secretaria Executiva , Caixa Postal 231, 36570-000 Viçosa MG Brasil, Tel.: (55 31) 3899 2471 - Viçosa - MG - Brazil
E-mail: sbcs@ufv.br