Fluxo de óxido nitroso do solo em sistema agroflorestal com palma de óleo em Tomé-Açu.

Abstract

In the state of Pará agriculture has a key role in generating income in the municipalities and assisting in the state's economy. The Para agriculture has highlighted economic growth, oil palm is a crop in expansion, mainly in the south of Pará state, agroforestry systems (AFS) consist of important agricultural practice of use of land dedicated to production and the provision of environmental services. The aim of this study was to quantify the soil N2O emissions to the atmosphere under the influence of different species, and to assess the relationship between the emission and the biotic and abiotic variables, in an agroforestry system with oil palm cultivation in the municipality of Tomé- Açu. The experiment was installed in the demonstration unit II (UD2) of the "palm Project: agroforestry systems in family farming." To evaluate the microbiological soil properties were collected with a Dutch auger, 16 soil samples, each consisting of 4 sub simple samples in the depth 0-5 cm and 16 samples in the depth 5-10 in January, April, July and October, coinciding two collections during the rainy season and two in the less rainy period the municipality, respectively. The analyzes were microbial biomass, mineral nitrogen, enzyme activity, as well as microbial activity (basal respiration). The collected air sample for analysis of concentration of nitrous oxide (N2O) was performedwith a static camera systems, consisting of base and lid, with cylindrical format. 16 cameras were distributed to collect gases, the selected locations were randomly 4 cacao trees, 4 spindles of ingá, palm nuts 4, 4 stacks. The collection of air was performed with polypropylene syringes with a volume of 20 ml. After collection, samples were immediately transferred to borosilicate flasks with a volume of 14 ml, the N2O concentration was determined by gas chromatography. The results showed that the collection sites not influence the emission of nitrous oxide, but the climatic conditions had a greater influence, and agroforestry systems with oil palm are efficient as the immobilization of C and N in the soil.