Caracterização dos atributos químicos e da dinâmica de decomposição de resíduos de madeira em terra preta nova - município de Tailândia- Pará

Abstract

In the Amazon there is an occurrence of soils that were formed from prehistoric human occupation. These soils, highly fertile and stable, called Terra Preta de Arqueológica (TPA), were sites of human habitation in the pre-Columbian past of the Amazon. To form the TPA, it seems that the abundance of organic matter of vegetal (leaves and stalks of various palms, cassava peels, seeds, etc.) and animal (bones, blood, fat, feces, chelonian shells, shells, etc.) origin was paramount. The project Economic use of wood residues as an alternative to minimize socio-environmental problems in the state of Pará is using residues from the wood industry and from slaughterhouses as an attempt to replicate these soils, called Terra Preta Nova (TPN). To this end, an experiment was set up in the city of Tailândia-PA, consisting of 17 treatments made up of charcoal, shredded blade residues, saw dust, butcher shop residues and their combinations, with four repetitions each, totaling 68 plots. The objective of the present work was to evaluate the behavior of Ca, Mg, Na, K, AI and pH in the soil over time. The results show that the pH had minimal variations around its average values, being mostly in the range of 5 to 6. Calcium showed a significant increase in the fourth and seventh collections for all treatments, with its highest values found in the treatments C+RPS+RLT,C+RA and C, which were 2.36; 1.96; and 1.95 cmolc/kg in the fourth collection, respectively, which shows that apparently the charcoal is contributing to the retention of this element compared to a blank of 1.23 cmolc/kg. Similarly, for Mg there was an increase in the values of this element with a higher value of 0.49 cmolc/kg for both treatment C and treatment with C+RPS+RTL in the fourth collection, followed by treatment C+RPS+RLT+RA also in the same collection, with a value of 0.41 cmolc/kg. Sodium proved to be quite heterogeneous in the three collections, as well as for the seventeen related treatments. In general, its lowest values were in the seventh collection, presenting as the highest value in the fourth collection 0.35 cmolc/kg, treatment C+RPS+RLT and 0.24 for the first collection, treatment C+RPS+RLT+RA+S. For K occurred for most treatments an increase of this element in the fourth and seventh collection, presenting the highest observed value of 0.35 cmolc/kg compared to the blank {0.0a cmolc/kgl. As for aluminum, the highest value found was 0.4 cmolc/kg for the treatment with C+RPS+ RA followed by the blank with a value of 0.36 cmoc/kg. Thus, there are significant changes in the chemical composition of the soil studied from the incorporation of organic waste.