ABSTRACT Soils with humic and histic horizons in tropical and subtropical ecosystems play an important role in determining the atmospheric C stock and its stabilization, climate regulation, water holding capacity, and environmental filtering, due to the different functions of soil organic matter (SOM). However, the processes and mechanisms that regulate SOM dynamics in these soils are not clear. The objectives of this study were: i) determine the C and N stocks and ii) investigate the SOM chemical fractions and their […]

ABSTRACT The interaction of organic compounds with clay minerals can change the size of crystals. However, in soils this effect is still unclear because of limitations in separation of pure mineral phases for conducting dissolution experiments. In this study, the relationship between soil organic matter (SOM) and mean crystallite size (MCS) of clay minerals from surface and subsurface horizons of soils from a toposequence in Southern Brazil was evaluated. Soil C and N contents were determined and the nature of […]

The exponential growth in poultry farming in Brazil has led to a parallel increase in the production of manure and poultry litter. The litter generated in this activity used to be largely employed as cattle feed. However, the enactment of a law that bans the use of poultry litter as animal feed intensified its use as organic fertilizer in agriculture. Despite its importance, there are gaps in our knowledge on an adequate use to obtain high plant yields without threatening […]