Earthworm management in tropical agroecosystems

A worldwide survey of earthworms in the humid tropics revealed that 51 exotics and 151 native species are commonly found in tropical agroecosystems. On the basis of frequency records and climatic and edaphic ranges, 21 exotics and 27 native species have been selected as possible candidates for manipulation. A multivariate analysis separated these species into four groups : (i) native species with wide edaphic and medium climatic tolerances ; (ii) exotic species with wide climatic and edaphic tolerances ; (iii) native and exotic species with narrow edaphic tolerances but more resistant to climatic variations ; and (iv) native species with limited tolerance for climatic and edaphic variations. Regarding management, species of group (ii) seem to be the most adaptable, both at regional and local levels (multipurpose species) ; group (i) can be managed for specific climatic conditions whereas group (iii) should be managed in specific soil environments. Species of group (iv) may only be managed at a very local scale. (Résumé d'auteur

Effect of a legume cover crop on carbon storage and erosion in an ultisol under maize cultivation in southern Benin

Field experiment was conducted from 1988 to 1999 at an experimental farm at Agonkanmey, near Cotonou in southern Benin, to study the effect of relay-cropping maize through Mucuna pruriens (var. utilis). The relay-cropping system was compared with traditional maize cropping system without any input, and with a maize cropping system with mineral fertilizers (NPK). Special attention was given on the changes in soil C during the period of the experiment in relation to residue biomass C returned to the soil, runoff and soil erosion losses, and loss of C with erosion. The soils are classified as sandy loam Typic Kandiustult. The general properties of these soils are given. For this soil type, relay cropping of maize and mucuna was very effective in enhancing C sequestration: change in Ct (total C content) stock for 0 to 40 cm depth was 1.3 t C/ha per year over the 12-year period of the experiment, ranging among the highest rates recorded for the eco-region. This increase resulted first from the high amount of residue biomass provided by mucuna, which amounted to 10 t DM/ha per year (83% aboveground). Mucuna residues, supplying the soil with N, also favoured the production of maize biomass, and total mucuna plus maize residue biomass returned to the soil was approximately 20 t/ha per year. In contrast, non-fertilized and fertilized continuous maize cultivation resulted in -0.2 and 0.2 t C/ha per year change in Ct stock for 0 to 40 cm depth, respectively. Total residue biomass was 8 and 13 t/ha per year, including 77 and 29% by weeds, respectively. Thick mulch produced by mucuna decreased losses by runoff and erosion, which were 0.28, 0.12 and 0.08 mm/mm and 34.0, 9.0 and 3.0 t/ha per year in unfertilized, fertilized with NPK and mucuna treatments, respectively. Eroded C was estimated at 0.3, 0.1 and 1.0 t C/ha per year in unfertilized, fertilized with NPK and mucuna treatments, respectively. Through its benefits on soil organic matter management, weed suppression and erosion control, cropping systems including a legume crop may have an adverse impact from a global change standpoint

Dab1 (Disable Homolog-1) Reelin Adaptor Protein Is Overexpressed in the Olfactory Bulb at Early Postnatal Stages

Dab1 mediates reelin signalling and plays critical roles in early brain development such as the stereotypical positioning of neurons in the brain. The olfactory bulb undergoes a prominent layering reorganization, but shows not apparent differences between wild type and reeler in the layer organization. Therefore, an accurate regional and cellular simultaneous analysis of these molecules becomes essential to clarify the role played by Dab1 upon Reelin effect. The present study reveals a strong and consistent Dab1 mRNA and protein expressions, throughout the olfactory bulb layers in both wild type and reeler mice. In addition, noteworthy is the pattern of Dab1 location within cell nuclei in both strains. Furthermore, a temporal increment of Dab1 expression levels is detected from P0 to P15 in both strains, being the protein quantity higher in reeler than in wild type mice. Altogether, our results revealed that Reln acts directly from projection neurons via the production of different Reln fragments. Changes in the pattern of Dab1 expression could reflect an alternative Reln function in postnatal and adult stages, besides a possible regulation of Dab1 by other molecules distinct to Reln

Effect of a legume cover crop (Mucuna pruriens var. utilis) on soil carbon in an ultisol under maize cultivation in southern Benin

Long term fallow is no longer possible in densely populated tropical areas, but legume cover crops can help maintain soil fertility. Our work aimed to study changes in soil carbon in a sandy loam Ultisol in Benin, which involved a 12-year experiment on three maize cropping systems under manual tillage: traditional no-input cultivation (T), mineral fertilized cultivation (NPK), and association with Mucuna pruriens (M). The origin of soil carbon was also determined through the natural abundance of soil and biomass C-13. In T, NPK and M changes in soil carbon at 0-40 cm were -0.2, +0.2 and +1.3 t C ha(-1) yr(-1), with residue carbon amounting to 3.5, 6.4 and 10.0 t C ha(-1) yr(-1), respectively. After 12 years of experimentation, carbon originating from maize in litter-plus-soil (0-40 cm) represented less than 4% of both total carbon and overall maize residue carbon. In contrast, carbon originating from mucuna in litter-plus-soil represented more than 50% of both total carbon and overall mucuna residue carbon in M, possibly due to accelerated mineralization of native soil carbon (priming effect) and slow mulch decomposition. Carbon originating from weeds in litter-plus-soil represented c. 10% of both total carbon and overall weed residue carbon in T and NPK. Thus mucuna mulch was very effective in promoting carbon sequestration in the soil studied

The role of biological activity (roots, earthworms) in medium-term C dynamics in vertisol under a Digitaria decumbens (Gramineae) pasture

Abstract The natural abundance of 13 C was used to estimate the turnover of the soil organic matter in a vertisol re-grassed with Digitaria decumbens (C4 plant) following intensive market gardening (C3 plants). In addition, the experimental design allowed us to determine the respective roles of roots and earthworms (Polypheretima elongata) in soil C stock restoration in D. decumbens pasture. The C stock increased from 31 to 37 Mg C ha −1 in 5 years and the ␦ 13 C increased from −18.1‰ in market gardening soil to −15.5‰ in the 5-year-old pasture soil in the upper 20 cm. Below the 20 cm soil layer, the C stock and the ␦ 13 C did not change significantly in 5 years. The net gain of 6 Mg C ha −1 was the balance of a loss of 5 Mg C ha −1 derived from market gardening and a gain of 11 Mg C ha −1 derived from D. decumbens. Effects of earthworms on the C dynamics were not discernible

La formación docente ante el trastorno del espectro autista

Teacher training in learning disorders is vital to achieve a true competence and inclusive education and physical activity acquires special significance. The objective of this study was to assess the training that teachers have active on students with Autism Spectrum Disorder (ASD) and what factors can influence the improvement of teaching practice. The sample consists of a total of 68 teachers from different public schools in the province of Toledo (CLM). An ad hoc questionnaire based on scientific literature and reviewed by experts was used. The results show how there is little training regarding the treatment of students with special educational needs and ASD students. Enhance the support within the classroom to the teacher and have more number and availability of intervention programs appropriate to each type of educational need, will serve to alleviate the possible shortcomings in this regard.La formación docente en trastornos del aprendizaje es vital para alcanzar una verdadera educación competencial e inclusiva y la actividad física adquiere especial significado. El objetivo del presente estudio fue valorar la formación que tienen los docentes en activo sobre el alumnado con Trastorno del Espectro Autista (TEA) y qué factores pueden influir en la mejora de la práctica docente. La muestra está formada por un total de 68 docentes de diferentes centros educativos públicos de la provincia de Toledo (CLM). Se utilizó un cuestionario ad hoc basado en la literatura científica y revisado por expertos. Los resultados muestran como existe una escasa formación respecto al tratamiento del alumnado con necesidades educativas especiales y alumnos TEA. Potenciar el apoyo dentro del aula al docente y disponer de mayor número y disponibilidad de programas de intervención adecuados a cada tipo de necesidad educativa, servirá para paliar las posibles carencias al respecto

Estereotipos de género en educación física

The school, and the Physical Education may become as one of the setting where with the so-called hidden curriculum, attitudes loaded with prejudices, in terms of gender stereotyped, could be shown.  The main objective of our study was to identify the perception of primary school students between 11 and 12 years old (11.87 ± 0.38) about gender stereotypes linked to physical activity and sport, based on sub-stereotypes associated with the type of practice , regarding the teaching staff and classroom climate. The main results show the presence of stereotypes related to performance, self-concept and treatment by teachers. From the school and from the area of Physical Education, we must bear in mind these situations that we must reorient to achieve a true inclusive school and society that allows equal opportunities.La escuela y en particular el área de Educación Física, puede ser uno de los escenarios donde, bajo el denominado currículum oculto, se pongan de manifiesto actitudes estereotipadas y cargadas de prejuicios desde el punto de vista deportivo y motor. El objetivo principal de nuestro estudio fue identificar la percepción de los escolares de Educación Primaria entre los 11 y 12 años (11.87± 0.38) sobre los estereotipos de género vinculados con la actividad física y el deporte, a partir de subestereotipos asociados al tipo de práctica, respecto al profesorado y a clima de clase. Los principales resultados muestran la presencia de estereotipos relacionados con el rendimiento, el autoconcepto y el trato por parte del profesorado. Desde la escuela y desde el área de Educación Física se debe tener muy presente estas situaciones que debemos reorientar para lograr una verdadera escuela inclusiva y sociedad que permita la igualdad de oportunidades