Atributos de fertilidade dos solos em sistemas agroflorestais familiares, no nordeste paraense.

Abstract

In the Amazon, the practice of slash and burn of secondary vegetation to prepare the area and increase the availability of nutrients offered to agricultural crops, cause damage to soil quality, increases greenhouse gas emissions and increasing the amount of deforested areas. Because of the need to reduce the negative effects resulting from this practice it was suggested to use the slash-and-mulch technique in capoeira (without burning) and the implementation of agroforestry systems therefore are sustainable alternatives and reduce the increasing environmental degradation. This study was conducted in order to demonstrate the importance of replacement degrading techniques for alternatives that offer benefits to the environment and farmers, show the need for diversification of crop areas to keep the system sustainable and denote the essentiality of the survey of soil fertility information by analyzing its chemical attributes. In the first chapter held a bibliographical research on family agriculture, agroforestry and soil chemical properties in the Amazon, so that you can analyze the importance of family farmers and their relation to the implementation of alternative techniques to replace the degradation. The second chapter was conducted in the municipality of Marapanim in the state of Para, where it assessed the chemical soil fertility in areas whose preparation was to slashand-mulch technique and slash-and-burn of secondary vegetation, which is contrasted with an area with poultry 30 years of age. The analysis of these attributes was made by collecting soil samples, which were analyzed according to the methodology used by the Embrapa laboratory. The determination of soil chemical properties showed that the burning of vegetation increased pH, phosphorus, calcium and magnesium and other attributes, it is concluded that the burned provided benefits to soil fertility immediately. Chapter 3 compared the chemical soil fertility in an agroforestry system 14, an agroforestry system 1 year and a farmyard area of 20-year-old in area of the municipality of Tomé-Açu. The analysis of these attributes was made by collecting soil samples, which were analyzed according to the methodology used by the Embrapa laboratory. The availability of nutrients was similar for the three areas can be concluded that the Agroforestry systems offer benefits to soil fertility just like a natural forest is able to offer.