Percepção de serviços ambientais e estoque de carbono no solo em áreas de assentamento rural na Amazônia Oriental, Brasil

Abstract

The present paper had the goal to evaluate the effects of the use soil systems about environmental services. In this perspective, we analyze farmers’ perceptions about environmental services (ES), socioeconomic aspects, the changes in using and land occupation, and to evaluate the carbon stock and fertility in use soil systems, in Jutaí Diamante Negro settlement project, Monção city, eastern Amazon, Brazil. Integrated geoprocessing methods were used to the socioeconomic and environmental analysis, and application of questionnaires. There were adults and elderly farmers, experienced in cutting and burning crops and ebbing, about half of them started elementary education and most are participative members of local social organizations determining aspects in their positions and/or opinions, in farmers’ perception, fishing is the most important environmental service (ES) and also is the most threatened. The spatial dynamics of the studied period, it highlights the reduction of water bodies. The farmers’ well-being is directly linked to security and solidarity. Reducing fishing and food production compromise adequate subsistence and access to goods, besides other components of well-being. In order to evaluate concentration and carbon C stock in use soil systems: itinerant agriculture (IA), pasture (P) mixed capoeira (MC) and secondary forest (SF) with four replicated of each system, and it was established a sample scheme, in an area of 2500 m2 composed for nine points, a central profile (1.2 x 1.0 x 1.2m) where were collected samples in layers of 10 to 10 cm until 1,0m depth and eight miniprofiles (0.7 x 0.7 x 0.7m) in which were collected samples in five soil layers 0-10, 10-20, 20- 30, 30-40 and 40-50 cm depth, totaling 50 samples per plot. The effect of the systems of using on the concentration and carbon C stock was checked by analysis of the single variance factor and then by the Tukey (p < 0,05). And software Statistic 8 was used. It was also collected 10- 20cm to analyze fertility of the research areas. The C concentration recorded in the depth of 0.10cm was 9,54g kg-1 on the pasture and 12,73g kg-1 on mixed capoeira. The carbon C stock recorded in the less disturbed system was: 15,67 Mg kg-1 in mixed capoeira and 12,72 Mg kg-1 in the secondary forest. In the depth of 0-30 cm is found 50% of the soil carbon stock in relation to the 0-100 cm profile. These results suggest that the system of cutting and burning to implantation of crops or pasture is directed to reduce the carbon stock in the soil, which increases the susceptibility to degradation. The systems of using evaluated did not have any effect on the concentration and carbon stock, and the fertility attributes, these presented low values that suggest the necessity to adopt. Appropriate soil management practices.