Avaliação da fertilidade do solo sob pastagem no município de Humaitá, região Sul do Amazonas

Abstract

The intensification and expansion of the development in the Amazon has provoked ruptures in the local traditional communities, and this area expansion has, as its main purpose, the livestock. The degree of alteration provoked by human intervention in the natural system can be rated, amongst other criteria, by the modification of some of the attributes of the soil. Based on this, the present work has, as an objective, assessing the fertility of the soil under pasture in the county of Humaitá, in the southern region of Amazonas. After analyzes on the chemical attributes and soil physics, the high acidity was evident, with a CaCl2 medium in pH of 4.01, reaffirming the diverse studies about the Amazonian soils, in which this stands out as the principal characteristic. Presenting even lower values in Ca, Mg, K and V%, in addition to extremely low levels of the micronutrients Zn, Bo, Cu, Fe and Mn. In relation to the physical attributes, the dominance of the silt fraction is highlighted in every area. After the calculation of the lime requirement (NC) for every area, the evidence showed that there are existing properties that necessitate of greater quantities of lime for the elevation of saturation by base, while others have a necessity that is similar to the medium of the county, which is 5.88 t/ha. Therefore, the importance of soil analyzes is highlighted, not solely for the visualization of fertility but also for the calculations of NC. It is necessary that more specific and deep studies for the livestock sector be done, while having in view the complex Amazon environment. This is essential for the future of Amazonian livestock.