CHEMICAL AND PHYSICAL ATTRIBUTES OF SOIL, AND CARBON AND NITROGEN STOCK AND HUMIC FRACTIONS IN DIFFERENT PLANT FORMATIONS

O Cerrado \ue9 o segundo maior bioma brasileiro, no qual s\ue3o observadas diferentes fei\ue7\uf5es fitofision\uf4micas, que podem ser influenciadas por fatores ed\ue1ficos. Desta forma, este estudo objetivou avaliar a fertilidade e os atributos f\uedsicos do solo (an\ue1lise granulom\ue9trica, densidade do solo - Ds e volume total de poros \u2013 VTP), os estoques de carbono e nitrog\ueanio e as fra\ue7\uf5es qu\uedmicas da mat\ue9ria org\ue2nica do solo (MOS) em \ue1reas de mata mesof\uedtica, cerrad\ue3o e cerrado sensu stricto na esta\ue7\ue3o ecol\uf3gica de Pirapitinga - MG. O solo das \ue1reas de estudo foi classificado como Latossolo Vermelho. Em cada uma das \ue1reas avaliadas foram coletadas amostras nas camadas de 0-0,05; 0,05-0,1; 0,1-0,2 e 0,2-0,4 m. O delineamento utilizado foi inteiramente casualizado. As \ue1reas de mata mesof\uedtica e cerrad\ue3o desenvolvem-se em solo com maiores teores de argila em compara\ue7\ue3o \ue0 \ue1rea de cerrado sensu stricto, indicando que possivelmente solos mais argilosos t\ueam maior capacidade de reten\ue7\ue3o de \ue1gua e fornecimento de nutrientes para atender mais adequadamente \ue0 demanda dessas vegeta\ue7\uf5es com maior porte. A \ue1rea de mata mesof\uedtica por apresentar maior deposi\ue7\ue3o de res\uedduos vegetais e estar em solo de textura argilosa est\ue1 proporcionando em algumas camadas do solo maiores teores de C org\ue2nico e subst\ue2ncias h\ufamicas, desencadeando menores valores de densidade do solo, maior volume total de poros e maior disponibilidade de P em rela\ue7\ue3o \ue0s demais fitofisionomias estudadas. No entanto, as \ue1reas de cerrad\ue3o e cerrado sensu stricto apresentam maiores valores de Mg, K, pH e menores valores de H+Al e Al em compara\ue7\ue3o \ue0 \ue1rea de mata mesof\uedtica, o que pode sugerir que estas fitofisionomias se estabelecem preferencialmente nos solos mais f\ue9rteis do bioma Cerrado. A rela\ue7\ue3o entre a fra\ue7\ue3o \ue1cido h\ufamico e fra\ue7\ue3o \ue1cido f\ufalvico indica que a vegeta\ue7\ue3o de mata mesof\uedtica apresenta em rela\ue7\ue3o \ue0 vegeta\ue7\ue3o de cerrad\ue3o e cerrado sensu stricto mat\ue9ria org\ue2nica do solo de melhor qualidade, que permite o estabelecimento de atributos f\uedsicos e qu\uedmicos favor\ue1veis ao desenvolvimento de plantas. Os maiores estoques de carbono s\ue3o verificados nas vegeta\ue7\uf5es de maior porte, cerrad\ue3o e mata mesof\uedtica. Entretanto, o maior teor e estoque de nitrog\ueanio do solo ocorrem na \ue1rea de cerrado sensu stricto.Cerrado biome is the second largest Brazilian biome, where different phyto-physiognomical features are observed, which may be influenced by soil factors. Thus, this study aimed to evaluate soil physical and fertility properties (particle size analysis, bulk density - BD and total pore volume - TPV), carbon and nitrogen stocks and chemical fractions of soil organic matter (SOM ) in areas of mesophytic forest, Cerrado and Cerrado sensu stricto in the ecological station of Pirapitinga, Minas Gerais state. The soil was classified as Oxisol and soil samples were collected from the layers 0-0.05, 0.05-0.1, 0.1-0.2, and 0.2-0.4 m. The experimental design was completely randomized. Areas of mesophytic forest and cerrado grow in soil with higher clay compared to the Cerrado sensu stricto, indicating that possibly more clayey soils have higher water holding capacity and nutrient supply to attend the demand more appropriately with larger vegetations. The mesophytic forest area by presenting high waste disposal of plant and be in the clayey soil is in some layers providing higher levels of soil organic C and humic substances, triggering lower values of bulk density, greater total porosity and availability of P in relation to other vegetation types studied. However, the closed areas and Cerrado sensu stricto have higher amounts of Mg, K, and lower pH, H + Al and Al compared to mesophitic forest area, which may suggest that these phytophysiognomies settle preferentially in the most fertile soils of Cerrado biome. The relationship between the humic acid and fulvic acid fraction indicates that the forest vegetation Mesophytic presents for vegetation of Cerrado and Cerrado sensu stricto soil organic matter of great quality, which allows the establishment of physical and chemical attributes favorable to the development of the plant. The largest stocks of carbon are verified in larger vegetation, cerrado and mesophytic forest. However, the higher grade and stock soil nitrogen occur in Cerrado sensu stricto