Under field conditions in the Amazon forest, soil bulk density is difficult to measure. Rigorous methodological criteria must be applied to obtain reliable inventories of C stocks and soil nutrients, making this process expensive and sometimes unfeasible. This study aimed to generate models to estimate soil bulk density based on parameters that can be easily and reliably measured in the field and that are available in many soil-related inventories. Stepwise regression models to predict bulk density were developed using data […]

The aim of this work was to evaluate the effects of human intervention, i. e., jungle clearing and introduction of pasture (Brachiaria sp), on the total-N and organic-C contents and humic acids, fulvic acids and humina fractions. This research was carried out in a forest near Porto Velho – Rondônia (Amazo Forest) and Senador Canedo – Goiás (“cerrado”). The soil samples were collected in 1995, from areas of primary vegetation and planted pasture, obeying a line with 24 points every […]