Soil microstructure alterations induced by land use change for sugarcane expansion in Brazil

© 2019 British Society of Soil Science Land use change (LUC) alters soil structure and, consequently, the functions and services provided by these soils. Conversion from extensive pasture to sugarcane is one of the largest land transitions in Brazil as a result of the growth of the domestic and global demands of bioenergy. However, the impacts of sugarcane expansion on the soil structure under extensive pasture remains unclear, especially when considering changes at the microscale. We investigated whether LUC for sugarcane cultivation impacted soil microstructure quality. Undisturbed soil samples were taken from two soil layers (0–10 and 10–20cm) under three contrasting land uses (native vegetation—NV, pasture—PA and sugarcane—SC) in three different locations in the central-southern Brazil. Oriented thin sections (30μm) were used for micromorphological analysis. The total area of pores decreased following the LUC in the following order: NV > PA > SC in both soil layers. The area of large complex packing pores (>0.01mm²) also decreased with the LUC sequence: NV>PA>SC. Qualitative and semi-quantitative micromorphological analysis confirmed porosity reduction was driven by the decrease in complex packing pores and that biological features decreased in the same LUC sequence as the quantitative parameters. Therefore, LUC for sugarcane expansion reduced microscale soil porosity, irrespectively of soil type and site-specific conditions, indicating that the adoption of more sustainable management practices is imperative to preserve soil structure and sustain soil functions in Brazilian sugarcane fields

Global data on earthworm abundance, biomass, diversity and corresponding environmental properties

14 p.Earthworms are an important soil taxon as ecosystem engineers, providing a variety of crucial ecosystem functions and services. Little is known about their diversity and distribution at large spatial scales, despite the availability of considerable amounts of local-scale data. Earthworm diversity data, obtained from the primary literature or provided directly by authors, were collated with information on site locations, including coordinates, habitat cover, and soil properties. Datasets were required, at a minimum, to include abundance or biomass of earthworms at a site. Where possible, site-level species lists were included, as well as the abundance and biomass of individual species and ecological groups. This global dataset contains 10,840 sites, with 184 species, from 60 countries and all continents except Antarctica. The data were obtained from 182 published articles, published between 1973 and 2017, and 17 unpublished datasets. Amalgamating data into a single global database will assist researchers in investigating and answering a wide variety of pressing questions, for example, jointly assessing aboveground and belowground biodiversity distributions and drivers of biodiversity change

Diferentes ambientes para avaliação da sensibiliade ao ácido giberélico em genótipos de trigo (Triticum aestivum L.) Different environment for the evaluation of giberellic and sensitivity in wheat (Triticum aestivum L.) genotypes

O presente trabalho foi conduzido com o objetivo de analisar diferentes ambientes para a identificação de genótípos portadores de genes redutores da estatura de planta em trigo, através da reação de sensibilidade ao ácido giberélico (AG). O experimento foi instalado no ano de 1995 em casa de vegetação (CV) e laboratório (LA) na Faculdade de Agronomia da Universidade Federal do Rio Grande do Sul - FA/UFRGS, Porto Alegre e a campo (CA), em Eldorado do Sul, RS. Foram avaliados 6 genótípos de diferentes estaturas de planta em 0 e I00ppm de AG em CV e LA e 0, 100 e l000ppm de AG aplicados quando as plantas apresentavam duas e quatro folhas em CA. A determinação da estatura foi realizada aos 20 dias após a aplicação do tratamento em CV, 18 dias em LA e em quatro avaliações semanais em CA. A separação dos genótípos de acordo com a sensibilidade ao AG foi possível nos três ambientes, sem que a ordem de resposta fosse alterada. A diferença de estatura entre os tratamentos foi utilizada para a comparação entre ambientes e as maiores diferenças de estatura foram observadas em CV e CA. A interação genótipo x ambiente não foi significativa revelando a possibilidade de realização do teste em campo. Para todos os tratamentos aplicados foi possível identificar os genótípos sensíveis ao AG a partir dos 7 dias, através da determinação da estatura e peta identificação visual das plantas.<br>This experiment was conducted to analyse different environments in lhe indentification of dv/arf genes m wheat througth lhe giberellic acid (GA) sensitivity reaction. The tests were conducted in 1995, in a greenhouse (GH), laboratory (LA) andfield (Ff) in Porto Alegre and Eldorado do Sul, RS, Brazil. Six genotypes with different heigth were evatualed in GH and LA by treatments with 0 and 100 GA ppm, and in lhe Fl, when plants had two tofour leaves in lhe treatments with 0, 100 and 1000 GA ppm. The heigth measurement was done 20 days after lhe aplication of GA in GH, 18 days in LA andfour-week evaluatíons in lhe FI. The identijication of GA sensitive genotypes was possible in ali environments. The heigth dijference between the treatments was used to compare the environments, and the targer difference were observed in GH and in the Fl. The genotype x environment interaction was not significam, demonstrating showing the possibility ofusing this identification test in thefield. Seven days after the tratment aplication the sensitive of GA genotypes could be detected througth height measurements and visual evaluation