Aplicação de sistemas de informação geográfica para a determinação do potencial natural de erosão dos solos no distrito de Sussundenga - Moçambique

Mestrado em Gestão e Conservação de Recursos Naturais - Instituto Superior de Agronomia / Universidade de ÉvoraThe erosion potential of soils in the district of Sussundenga, Manica Province, is analyzed in this study by applying the USLE. The motivation for this study emerged from the need for research of susceptible areas to erosion and providing information about guidelines to minimize the problems of environmental degradation. This motivation is increased by the need to create a database containing details for the methodology to use in determining factors that cause soil degradation in Mozambique. The interest in the district of Sussundenga comes from implementation of the UN Convention to Combat Desertification, where this area was indicated as an area of high risk. The work is based mainly on literature review and spatial modeling in a GIS environment, using the software ArcGis 10. The data used were the digital elevation models, the spatial distribution of rainfall and soil characterization, from which the LS, R and K factors were obtained, respectively, of the USLE model. In GIS it was done the multiplication of thematic maps, resulting in a map indicating the levels of susceptibility to erosion at district. The study showed that about 50% of the district area presents values of Natural Potential of Erosion (NPE) less than 500 ton/ha, corresponding to the class of low potential. On the other hand, 27% of the area corresponds at the class of very high erosion potential. The topographic factor exerts a strong influence on these results, since there is a positive correlation between the two factors, and the correlation coefficient is equal to 99.9%

Switchgrass and Giant Reed Energy Potential when Cultivated in Heavy Metals Contaminated Soils

Funding Information: This work was supported by the Mechanical Engineering and Resource Sustainability Center—MEtRICs, which is financed by national funds from Fundação para a Ciência e Tecnologia, FCT/MCTES (UIDB/04077/2020 and UIDP/04077/2020). Publisher Copyright: © 2022 by the authors.The cultivation of energy crops on degraded soils contributes to reduce the risks associated with land use change, and the biomass may represent an additional revenue as a feedstock for bioenergy. Switchgrass and giant reed were tested under 300 and 600 mg Cr kg−1, 110 and 220 mg Ni kg−1, and 4 and 8 mg Cd kg−1 contaminated soils, in a two year pot experiment. Switchgrass yields (average aerial 330 g.m−2 and below ground 430 g.m−2), after the second year harvest, were not affected by Cd contamination and 110 mg Ni kg−1, but 220 mg Ni kg−1 significantly affected the yields (55–60% reduction). A total plant loss was observed in Cr-contaminated pots. Giant reed aboveground yields (control: 410 g.m−2), in the second year harvest, were significantly affected by all metals and levels of contamination (30–70% reduction), except in 110 mg Ni kg−1 pots. The belowground biomass yields (average 1600 g.m−2) were not affected by the tested metals. Contamination did not affect the high heating value (HHV) of switchgrass (average 18.4 MJ.kg−1) and giant reed aerial fractions (average 18.9 MJ.kg−1, stems, and 18.1 MJ.kg−1, leaves), harvested in the second year, indicating that the biomass can be exploited for bioenergy.publishersversionpublishe