Dinâmica sazonal de nutrientes e atributos físicos do solo em sistemas agroflorestais.

Abstract

With the application of agroforestry techniques, the productivity of agricultural establishments and forest plantations of various dimensions can stabilize, avoiding soil degradation or loss of productivity, over the years. The edaphoclimatic factors, such as light, temperature and humidity in the soil, also influence the maintenance of production and agroforestry systems (SAFs) as they constitute an important strategy to guarantee greaterstability of these conditions. The objective of this work was to evaluate soil physical and chemical properties in different agroforestry systems, considering the seasonality (dry andrainy period) and the effect of management in these areas. The study was carried out inthree different agroforestry systems, all located in the municipality of Belterra (PA), through chemical and physical evaluation, soil luminosity and temperature in relation to climatic variables. The nutrients showed, for most of the year, low levels in the soil (0-20 cm deep)and in all SAFs the nutrient cycling still does not provide the necessary amount of nutrientsto maintain the production needs of the crops. Most of the nutrients presented low soil content(0-20 cm depth) of SAFs, with SAF1 having the highest percentages of clay (24.0%) andSAF3 with the highest amount of sand (89.5%), soil density values determined were belowthe critical limits for vegetation. Soil moisture, in May, was observed in systems with higher clay contents. And the edaphic conditions are strongly influenced by the handling of the SAFs and by the composition and arrangement of the inserted species.