Mulching and soil tillage influence on the thermal behaviour of a Luvisol surface layer

Important energy exchanges at soil surface regulate the thermal environment within top soil layer and the boundary layer above it. By this reason, the application of mulches or the modelling of micro relief by soil tillage are common practises to modify the thermal regime of a soil. The aim of this study is to compare the effect on thermal behaviour of a Luvisol resulting of soil tillage and the application of stubble mulch and, different amounts of straw mulch. For this purpose, experiments were performed from January to May 2007 in a field sowed with winter wheat. Temperatures were measured with copper-constantan (Type T) thermocouples placed over straw and over stubble, at soil surface and at 2, 4 and 8 cm depth. Temperatures above canopy were also recorded. Daily mean temperatures and thermal amplitudes in the top soil layer covered by straw mulch were smaller than those verified either by stubble mulch or with soil tillage. Daily minimum temperatures in mobilized plots or covered by stubble mulch were smaller than those verified in plots covered by straw mulch, therefore being the former treatments more susceptible to frost than the later ones. Thermal differences between the four plots decreased significantly with wheat growth. Implications of these techniques of soil temperature control for crop growth are also discussed

Mulching and soil tillage influence on the thermal behaviour of a Luvisol surfacel layer

Important energy exchanges at soil surface regulate the thermal environment within top soil layer and the boundary layer above it. By this reason, the application of mulches or the modelling of micro relief by soil tillage are common practises to modify the thermal regime of a soil. The aim of this study is to compare the effect on thermal behaviour of a Luvisol resulting of soil tillage and the application of stubble mulch and, different amounts of straw mulch. For this purpose, experiments were performed from January to May 2007 in a field sowed with winter wheat. Temperatures were measured with copper-constantan (Type T) thermocouples placed over straw and over stubble, at soil surface and at 2, 4 and 8 cm depth. Temperatures above canopy were also recorded. Daily mean temperatures and temperature amplitudes in the top soil layer covered by straw mulch were smaller than those verified either by stubble mulch or with soil tillage. Daily minimum temperatures in mobilized plots or covered by stubble mulch were smaller than those verified in plots covered by straw mulch, therefore being the former treatments more susceptible to frost than the later ones. Thermal differences between the four plots decreased significantly with wheat growth. Implications of these techniques of soil temperature control for crop growth are also discussed

Monetary Poverty, Material Deprivation and Consistent Poverty in Portugal

In this paper we use the Portuguese component of the European Union Statistics on Income and Living Conditions (EU-SILC) to develop a measure of consistent poverty in Portugal. It is widely agreed that being poor does not simply mean not having enough monetary resources. It also reflects a lack of access to the resources required to enjoy a minimum standard of living and participation in the society one belongs to. The coexistence of material deprivation and monetary poverty leads to the concept of consistent poverty. The assessment of material deprivation and the identification of the households and individuals living in consistent poverty could become essential parts of the national anti-poverty strategy and crucial instruments in the definition of the target groups in social policy.Multidimensional poverty measurement, material deprivation, consistent poverty, Portugal.

Spatial variability of soil properties and soil erodibility in the Alqueva reservoir watershed

The aim of this work is to investigate how the spatial variability of soil properties and soil erodibility (K factor) were affected by the changes in land use allowed by irrigation with water from a reservoir in a semiarid area. To this end, three areas representative of different land uses (agroforestry grassland, lucerne crop and olive orchard) were studied within a 900 ha farm. The interrelationships between variables were analyzed by multivariate techniques and extrapolated using geostatistics. The results confirmed differences between land uses for all properties analyzed, which was explained mainly by the existence of diverse management practices (tillage, fertilization and irrigation), vegetation cover and local soil characteristics. Soil organic matter, clay and nitrogen content decreased significantly, while the K factor increased with intensive cultivation. The HJ-Biplot methodology was used to represent the variation of soil erodibility properties grouped in land uses. Native grassland was the least correlated with the other land uses. The K factor demonstrated high correlation mainly with very fine sand and silt. The maps produced with geostatistics were crucial to understand the current spatial variability in the Alqueva region. Facing the intensification of land-use conversion, a sustainable management is needed to introduce protective measures to control soil erosion

Choques al hogar, trabajo Infantil y acumulación de capital humano : evidencia para Colombia

En este trabajo se estima el efecto que tienen distintos choques a los hogares sobre el logro académico de los niños. Mediante un modelo de regresión lineal, se encuentra un efecto adverso de la presencia de choques sobre el puntaje de la prueba Saber 11. Además, los resultados sugieren que el trabajo infantil es un mecanismo por el cual los choques afectan negativamente la acumulación de capital humano. Al explorar efectos heterogéneos por sexo y edad, las estimaciones indican que el efecto de los choques es guiado por los hombres y los adolescentes mayores a 14 años.This paper analyzes the effect of different household shocks on children's academic achievement. Using a linear regression model, an adverse effect of the presence of shocks on test scores is found. In addition, the results suggest that child labor is a mechanism by which household shocks negatively affect human capital accumulation. By exploring heterogeneous effects by sex and age, estimates indicate that the effect of shocks is guided by men children and teenagers older than 14 years.Universidad del Rosari

Maternal employment and childhood nutrition in Ecuador

Treballs Finals del Màster d'Economia, Facultat d'Economia i Empresa, Universitat de Barcelona, Curs: 2020-2021, Tutor: Joan GilThis study explores the association of maternal employment on childhood nutrition in Ecuador by understanding the trade-off between the maternal time devoted to work and childcaring. I use exogenous regional variation of the labor market as an instrument. Using the National Health and Nutrition Survey 2018, I estimate the causal effect of maternal labor supply on children’s nutrition outcomes based on anthropometrics measurements. Maternal employment increases the probability of having stunted children, while I have not found any effect of maternal employment on children suffering from wasting, underweight and overweight. The results are robust and account for possible endogeneity sources

Revisiting the statistical isotropy of GRB sky distribution

The assumption of homogeneity and isotropy on large scales is one of the main hypotheses of the standard cosmology. In this paper, we test the hypothesis of isotropy from the two-point angular correlation function of 2626 gamma-ray bursts (GRB) of the FERMI GRB catalogue. We show that the uncertainties in the GRB positions induce spurious anisotropic signals in their sky distribution. However, when such uncertainties are taken into account no significant evidence against the large-scale statistical isotropy is found. This result remains valid even for the sky distribution of short-lived GRB, contrarily to previous reports.Comment: 9 pages, 10 figures, 2 tables, match accepted versio

How Does the Law Put a Historical Analogy to Work?: Defining the Imposition of “A Condition Analogous to That of a Slave” in Modern Brazil

Over the last decades, the Brazilian state has engaged in concerted legal efforts to identify and prosecute cases of what officials refer to as “slave labor” (trabalho escravo). At a conceptual level, the campaign has paired the constitutional protection of human dignity and the “social value of labor” with an expansive interpretation of the offense described in Article 149 of the Criminal Code as “the reduction of a person to a condition analogous to that of a slave.” At the operational level, mobile teams of inspectors and prosecutors have intervened in thousands of work sites, and labor prosecutors have obtained hundreds of consent agreements and convictions in the labor courts, a civil branch of the judiciary. Between the mid-1990s and the end of 2016, some 51,000 workers were administratively resgatados (“rescued”) from rural and urban workplaces in which inspectors determined that they had been reduced to a condition analogous to slavery. Under the supervision of the inspectors, labor contracts have been administratively cancelled, back pay has been (when possible) extracted from the employer, and unemployment insurance payments have been provided to the rescued workers