Pedochronology and development of peat bog in the environmental protection area pau-de-fruta – Diamantina, Brazil
01/Dec/2010
In the region of the Serra do Espinhaço Meridional, peat bog is formed in hydromorphic environments developed in sunken areas on the plain surfaces with vegetation adapted to hydromorphic conditions, favoring the accumulation and preservation of organic matter. This pedoenvironment is developed on the regionally predominant quartzite rocks. Peat bog in the Environmental Protection Area – APA Pau-de-Fruta, located in the watershed of Córrego das Pedras, Diamantina,Brazil, was mapped and three representative profiles were morphologically characterized and sampled for physical, […]
Redox index of soil carbon stability
01/Oct/2010
As an alternative to the relatively complex and expensive spectroscopic methods, the redox properties of humic acids, determined by potentiometric titrations, have been used to evaluate the stability of soil organic C. The objective of the present study was to establish a Redox Index of C Stability (RICS) and to correlate it with some properties of the humic acids extracted from different modal soils in Brazil (distinct weathering stages or management) to facilitate system comparison. The RICS was efficient for […]
Carbon storage in the soil and in the biomass of eucalypt plantations
01/Aug/2010
Eucalypt is the main commercial forest species in Brazil, but very little information is available in the literature on the amount of carbon stored in the soil and in the biomass of these forest stands. The main objective of this study was to estimate the amount of soil-stored carbon (SSC) of eucalypt plantations and determine soil and climate characteristics that influence SSC. The study was carried out in the Central-Eastern region of Minas Gerais State, Brazil, in five micro-regions (CO, […]
Spodosols pedogenesis under barreiras formation and sandbank environments in the south of Bahia
01/Jun/2010
Morphologically differentiated Spodosols usually occur in the Coastal Plain of the South of Bahia and North of Espírito Santo. They are found in profiles known as “muçungas”, i.e. sandy soils that accumulate water. In these areas, two kinds of Spodosols, different from those in the Restinga area, can be found: Spodosols with E albic horizon (white muçunungas) and without this horizon (black muçunungas). Eight soil profiles with spodic characteristics were collected and described in order to evaluate differences in the […]
Carbon and nitrogen mineralization in soils under an eucalyptus plantation chronosequence
01/Jun/2010
To maximize the efficiency of N uptake by plants it is important to study N and C mineralization, particularly in the case of eucalyptus, which has a very low response to nitrogen fertilization. The rates of C and N mineralization and C and N mineralization potential were estimated, in soils under 1, 3, 5, and 13 year-old eucalyptus plantations with similar soil and climatic conditions. Soil from the 0-10 cm layer was sampled in November 2003. The samples were incubated under aerobic […]
Physical and chemical properties of an oxisol cultivated under pastures with distinct use history
01/Oct/2009
The sustainable use of pasture systems depends mainly on a management that promotes soil quality. This study aimed to evaluate changes in the physical and chemical soil properties of four areas under pasture growing the species Andropogon gayanus, Brachiaria decumbens and Brachiaria brizantha, cv. marandu, with different usage histories, in comparison to the reference of the natural Cerrado. The soil was evaluated based on the following properties: cation exchange capacity, soil organic matter, bulk density, porosity and soil mechanical penetration […]
Peat bogs of the Serra do Espinhaço Meridional – Minas Gerais, Brazil. I – characterization and classification
01/Oct/2009
Peat bogs are a special environment for studies related with the dynamics of organic matter, landscape evolution and climatic changes and with local, regional and global cycles of atmospheric pollution. Peat bogs contribute to the global C sequestration, act as water reservoirs and are the habitat of an endemic biodiversity. The Serra do Espinhaço Meridional (Minas Gerais State, Brazil) – SdEM – a terrestrial biosphere reservation area, contains a considerably large area with different types of peat bogs, which were […]
Peat bogs in the Serra do Espinhaço Meridional – Minas Gerais, Brazil. II – influence of drainage on elemental humus composition and substances
01/Oct/2009
Peat bogs are Organosols formed under ideal ecological conditions in terms of the accumulation of organic material, controlled by geomorphological and geological processes and climate. The physical, chemistry and biological constitution of peat bogs is largely unknown. In this study the peat bogs of the Southern Serra do Espinhaço (Minas Gerais, Brazil) were described and sampled from three profiles at 1,250 m (P1), 1,350 m (P4) and 1,800 m (P2) above sea level. The three profiles were characterized morphologically, the […]
Potential and net nitrogen mineralization in soils
01/Apr/2009
The soil incubation methods can be used as tools to a better evaluation of N mineralization and availability. The objective of this study was to evaluate the potential and net soil organic N mineralization, and relate them to N availability to plants. Twenty two soil samples (0-20 cm) were incubated at 35 ºC for 30 weeks in aerobic conditions and at 40 ºC for seven days in anaerobic conditions, and tested in a greenhouse experiment on corn plants. During the 30 weeks-incubation period […]
Soil organic carbon budget under crop-livestock integration in southern Brazil
01/Dec/2008
In southern Brazil, crop-livestock integration is increasing in areas traditionally used for extensive beef cattle production. The poor winter pasture management associated to the use of soybean monoculture in the summer may be restrictive for the incorporation of plant residues into the soil and reduce soil organic carbon stocks. The objective of this study was to evaluate the impact of the increase of winter pasture grazing frequencies and summer crop systems on the soil organic C stock. The experiment was […]