Carbon and water footprints in Brazilian coffee plantations - the spatial and temporal distribution

The future of many coffee growing regions, such as Brazil, depends on strategies to allow the minimization of the negative impacts of climate change. Still the own contribution of coffee cultivation for global warming is largely unknown. Water and carbon footprints are concepts that indicate the potential negative impact of a specific product, underlining which part of the process is the major responsible for it. In this context, the objective of this study was to quantify and spatialize the water and carbon footprints from coffee crop in different regions of Brazil, and to find the proportional weight of coffee production in the total emission of CO2 and water consumption in the context of Brazilian agriculture. For this end, water and carbon footprints were estimated and spatialized for Brazilian regions along 10 productive seasons (from 2004/2005 to 2014/2015), based on data of plantation area (ha) and coffee production (tons of beans). It is concluded that the estimates of annual carbon and water footprints were 19.791 million t CO2-equivalent and 49,284 million m3 of water, with higher values from the Southeast region. This corresponded to a moderate (ca. 5%) value for the emissions of greenhouse gases, but a relevant water footprint in the context of Brazilian agricultureinfo:eu-repo/semantics/publishedVersio

Vacuum polarization by a global monopole with finite core

We investigate the effects of a $(D+1)$-dimensional global monopole core on the behavior of a quantum massive scalar field with general curvature coupling parameter. In the general case of the spherically symmetric static core, formulae are derived for the Wightman function, for the vacuum expectation values of the field square and the energy-momentum tensor in the exterior region. These expectation values are presented as the sum of point-like global monopole part and the core induced one. The asymptotic behavior of the core induced vacuum densities is investigated at large distances from the core, near the core and for small values of the solid angle corresponding to strong gravitational fields. In particular, in the latter case we show that the behavior of the vacuum densities is drastically different for minimally and non-minimally coupled fields. As an application of general results the flower-pot model for the monopole's core is considered and the expectation values inside the core are evaluated.Comment: 22 pages, 4 figures, misprint is corrected, discussion is added, figures are change

Double-cross hybrid selection for aluminum tolerance

Um grupo de linhagens selecionadas per se e em top-cross para tolerância à toxidez de alumínio, foi utilizado na obtenção de híbridos duplos com tolerância ao Al. Estes híbridos duplos originaram-se do cruzamento de dez diferentes híbridos simples, com dois híbridos simples (HS1 e HS2) testadores comuns tolerantes ao Al, HS1 e HS2, obtendo-se dois grupos de dez híbridos duplos. Foi avaliado se a produtividade e estabilidade de produção dos híbridos tolerantes ao Al, quando plantados em solos mais férteis, seriam compatíveis com as dos híbridos comerciais de menor tolerância. A tolerância ao Al foi avaliada em solução nutritiva contendo 222 µmol Al litro-1 e 45 µmol P litro-1. A produtividade e estabilidade destes híbridos foram avaliadas em ensaios plantados em solos de cerrado recuperado e de cultura, usualmente utilizados para cultivo de milho. Os resultados indicam a possibilidade de obtenção de cruzamentos específicos superiores para tolerância ao Al, a partir de linhagens selecionadas para tolerância ao Al. Para tal, a técnica de solução nutritiva descrita mostrou-se eficiente na identificação destes cruzamentos. Não foi constatada uma possível correlação negativa entre produtividade e alta tolerância ao Al, e esta tolerância pode ser incorporada a genótipos de alta produtividade e estabilidade de produção. A set of maize inbred lines selected based on evaluation per se and as top-cross hybrids for aluminum tolerance, were used for obtaining Al tolerant double-cross experimental hybrids. These double-cross hybrids originated from the crossing of ten different single-cross hybrids with two common Al tolerant single-cross testers, HS1 and HS2, obtaining two sets of ten double-cross hybrids. Yield and stability of the Al tolerant hybrids were evaluated in high fertile soils and compared to less Al tolerant commercial hybrids. Aluminum tolerance was assessed in a nutrient solution with 222 µmol Al L-1 and 45 µmol P L-1. Yield and yield stability were tested in field trials at five sites on soils where maize is normally grown as well as cerrado soils. These results indicate the possibility of obtaining superior Al tolerant specific crosses from selected Al tolerant inbred lines. The nutrient solution technique described was effective in detecting superior Al tolerant crosses. It was not possible to find a negative correlation between yield and high Al tolerance, and high Al tolerance may be added to high yield and stable genotypes.