%0 Journal Article
%T Oxidizable carbon fractions in Red Latosol under different management systems Fra  es oxid¨¢veis do carbono em Latossolo Vermelho sob diferentes sistemas de manejo
%A Roni Fernandes Guareschi
%A Marcos Gervasio Pereira
%A Adriano Perin
%J Revista Ci¨ºncia Agron£¿mica
%D 2013
%I Universidade Federal do Cear¨¢
%X The aim of this study was to evaluate the oxidizable fractions of organic C in a Red Latosol in an area of cerrado under a no-tillage system (NT) with different years of implantation, and to compare them to areas of native cerrado and pasture. The experimental design used was completely randomized with five replications. Treatments consisted of five areas: native cerrado (NC) "stricto sensu"; pasture (PA) planted with Brachiaria decumbens; NT with 3 (NT3); NT with 15 (NT15) and NT with 20 (NT20) years of implantation. There was an increase in the ground-surface mass of vegetable residue as a function of the time of implantation of the NT. An increase in C content and the carbon-management index (CMI) can be seen as a function of the time of implantation of the NT. In the area of NT20 the greatest values of C were quantified, compared to the area of cerrado. In general, there are increased labile and stable MOS fractions as a function of the implantation time of the NT, while the areas SPD15 and SPD20 present a C content among fractions, respectively similar and/or superior to the area of NC. Regardless of the area evaluated, a predominance of the more stable MOS fractions (F3+F4) can be seen. The area of PA, due to inadequate management, shows a more advanced stage of degradation when compared to the other areas, as there is a large reduction in the levels of total C, of C in the more labile and stable MOS fractions, as well as lower CMI values. Objetivou-se com este trabalho avaliar as fra  es oxid¨¢veis de C organico em um Latossolo Vermelho em ¨¢rea de cerrado sob sistema de plantio direto (SPD) com diferentes anos de implanta  o, e compar¨¢-las a ¨¢reas de cerrado nativo e pastagem. O delineamento utilizado foi inteiramente casualizado, com cinco repeti  es. Os tratamentos consistiram de cinco ¨¢reas: cerrado nativo (CE) "stricto sensu"; pastagem plantada (PA) com Brachiaria decumbens; SPD com 3 (SPD3); SPD com 15 (SPD15) e SPD com 20 (SPD20) anos de implanta  o.Foi observado aumento na massa dos res¨ªduos vegetais da superf¨ªcie do solo em fun  o do tempo de implanta  o do SPD. Verifica-se aumento nos teores de C e no ¨ªndice de manejo de carbono (IMC) em fun  o do tempo de implanta  o do SPD. Na ¨¢rea de SPD20 quantificaram-se maiores valores de C em rela  o ¨¤ ¨¢rea de cerrado. De maneira geral, verifica-se aumento das fra  es l¨¢beis e est¨¢veis da MOS em fun  o do tempo de implanta  o do SPD, sendo que as ¨¢reas SPD15 e SPD20 apresentam teores de C dentre as fra  es semelhantes e/ou superiores respectivamente a ¨¢rea de CE. Independentemente da ¨¢rea avaliada,
%K Plantio direto
%K Pastagem
%K Mat¨¦ria organica do solo
%K Carbono l¨¢bil
%K No-tillage
%K Grassland
%K Soil organic matter
%K Labile carbon
%U http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1806-66902013000200005