Evolució de la fracció orgànica d'un femer durant la fermentació

Proposem un seguit de paràmetres: — % M.O. — Relació C/N — Grau de Descomposició — Concentració en Acids Fúlvics — Concentració en Acids Húmics, per caracteritzar el procés de maduració d'un adob orgànic, en aquest cas fern de vaca. Veiem corn efectivament aquests paràmetres responen d'una forma coherent a mesura que augmenta la qualitat d'aquest producte durant la seva fermentació, concretament: — el % de M.O. disminueix — la relació C/N augmenta — el Grau de Descomposició augmenta — la concentració en Acids Fúlvics disminueix — la concentració en Acids Húmics augmenta cap a formes més evolucionades.Parameters as —% M.O. (organic matter) —C/N rate —Descomposition Degree —Fulvic Acid concentration —Humic Acid concentration, are introduced to characterize cattle manure during its fermentation. All parameters responded in a consistent way, particularly: —% M.O. decreases —C/N rate increases —Descomposition Degres increases —Fulvic acid concentration decreases —Humic acid concentration increases to more developed forms.Se proponen un conjunto de parámetros, —% de M.O. —Relación C/N —Grado de Descomposición —Concentración en Acidos Fúlvicos —Concentración en Acidos Húmicos —Concentración en Acidos Húmicos, para caracterizar un abono orgánico, estiércol de vaca en esta ocasión. Se puede observar como estos parámetros responden de una forma coherente a medida que aumenta la calidad de este producto durante su fermentación, así: —el % de M.O. disminuye —la relación GIN aumenta —el Grado de Descomposición aumenta —la concentración en Acidos Fúlvicos disminuye —la concentración en Acidos Húmicos aumenta hacia formas más evolucionadas

Representative taxa in field trials for environmental risk assessment of genetically modified maize

When assessing the benefits and risks of transgenic crops, one consideration is their relative effects on non-target arthropod (NTA) abundance and functions within agroecosystems. Several laboratory and field trials have been conducted in Spain since the late 1990s to assess this issue. A consideration in the design of field trials is whether it is necessary to sample most NTAs living in the crop or only representative taxa that perform main ecological functions and have a good capacity to detect small changes in their abundance. Small changes in the field abundance of an effective representative taxon should be detectable using standard experimental protocols. The ability of a species to reveal differences across treatments may be analysed by examining the detectable treatment effects for surveyed non-target organisms. Analysis of data from several NTAs recorded in 14 field trials conducted over 10 years using complete block designs allowed us to select a number of representative taxa capable of detecting changes in the density or activity of arthropod herbivores, predators, parasitoids and decomposers in transgenic and non-transgenic maize varieties. The most suitable NTA as representative taxa (with detectable treatment effects below 50%) included leafhoppers among arthropod herbivores, Orius spp., Araneae, and Carabidae among predators, chalcidids, particularly the family Mymaridae, among parasitoids and Chloropidae as decomposer. Details of sampling techniques for each sampled taxa and their advantages and disadvantages are discussed. It is concluded that abundance of taxa is the most influential factor determining their capacity to detect changes caused by genetically modified varieties.Peer ReviewedPostprint (published version

The Catalan butterfly monitoring scheme has the capacity to detect effects of modifying agricultural practices

Impacts of agricultural management practices on the receiving environment are seldom suitably assessed because environmental monitoring is costly. In this regard, data generated by already existing environmental survey networks (ESNs) may have sufficient capacity to detect effects. Here, we study the capacity of the Catalan butterfly monitoring scheme (CBMS) to detect differences in butterfly abundance due to changes in agricultural practices. As a model, we compared butterfly abundance across two landscape types according to agricultural intensification. A 2 km diameter buffer area was centered on the CBMS transect, the control group were transects located in areas where intensive agriculture represented <20% of the area; a treated group was simulated by selecting transects located in areas where intensive agriculture occupied an area over 40%. The Welch t‐test (α = 0.05 and 80% power) was used to compare butterfly abundance per section across landscape types. The capacity of the t‐test to detect changes in mean butterfly abundance, of 12 butterfly indicators relevant to farmland, was calculated annually and for 5‐, 10‐, and 15‐yr periods. Detection capacity of the t‐test depended mainly on butterfly data sample size and variability; difference in butterfly abundance was less important. The t‐test would be capable of detecting acceptably small population changes across years and sites. For instance, considering a 15‐yr period, it would be possible to detect a change in abundance below 10% of the multispecies indicators (all butterfly species, open habitat species, mobile species, and grassland indicators) and two single species (Lasiommata megera and Lycaena phlaeas). When comparisons were carried out within each year, the t‐test would only be capable of detecting a change below 30% for all butterfly species, mobile species, and L. megera. However, detection capacity rapidly improved with the addition of further years, and with 5 yr of monitoring, all indicators but Thymelicus acteon had a detection capacity below 30%. We therefore conclude that, from a statistical point of view, the CBMS data “as is” are sensitive enough for monitoring effects of changes in agricultural practices. It could be used, for instance, for the general surveillance of genetically modified crops.This work was partially supported by the Spanish Government‐funded project AGL2011‐23996 and a FI‐DGR scholarship to M. Lee from the Catalan Government

Eficiencia en el proceso de tratamiento de la fracción orgánica de los residuos municipales (FORM). Estudio del caso Ecoparc 2 de Montcada i Reixach, Barcelona

La fracción orgánica de los residuos municipales (FORM) comprende residuos procedentes de hogares particulares y residuos similares de otros establecimientos que los municipios recogen junto con la basura doméstica. Estos residuos constituyen entre el 30 y 50% de la masa total de los residuos sólidos municipalesPostprint (published version

Recovery of nutrients from organic fraction of municipal sólid waste (OFMSW) in the Ecoparc 2 of Montcada i Reixac, Barcelona: alternatives to the current process

Recovery of nutrients from the OFMSW is a relevant topic as evidenced by the European initiative \”End of Waste\”. Following this guideline, the Ecoparc 2 of Montcada i Reixac, belonging to the Metropolitan Area of Barcelona, submits the OFMSW to anaerobic digestion and then the digestate is separated mechanically, fisrt by pressing and then by centrifugation. The solid of press (Sp) and the solid of centrifugue (Sc) are com- posted together (CSp+Sc) and used as organic fertilizer. There are alternatives to the current treatment of the OFMSW as: (1) direct use of Sc as fertilizer, (2) composting of Sc (CSc) and (3) composting of Sp (CSp). This paper focuses on analyzing the recovery of nutrientsPostprint (published version

Occurrence and bioaccumulation of chemical contaminants in lettuce grown in peri-urban horticulture

Peri-urban horticulture performs environmental and socio-economic functions and provides ecological services to nearby urban areas. Nevertheless, industrialization and water pollution have led to an increase in the exposure of peri-urban vegetables to contaminants such as trace elements (TEs) and organic microcontaminants (OMCs). In this study, the occurrence of chemical contaminants (i.e., 16 TEs, 33 OMCs) in soil and lettuce leaves from 4 farm fields in the peri-urban area of the city of Barcelona was assessed. A rural site, outside the peri-urban area of influence, was selected for comparison. The concentration of TEs and OMCs ranged from non-detectable to 803¿mg/kg¿dw and from non-detectable to 397¿µg/kg¿dw respectively in the peri-urban soil, and from 6¿·¿10-5 to 4.91¿mg/kg¿fw and from non-detectable to 193¿µg/kg¿fw respectively in lettuce leaves. Although the concentration of Mo, Ni, Pb, and As in the soil of the peri-urban area exceeded the environmental quality guidelines, their occurrence in lettuce complied with human food standards (except for Pb). The many fungicides (carbendazim, dimetomorph, and methylparaben) and chemicals released by plastic pipelines (tris(1-chloro-2-propyl)phosphate, bisphenol F, and 2-mercaptobenzothiazole) used in agriculture were prevalent in the soil and the edible parts of the lettuce. The occurrence of these chemical pollutants in the peri-urban area did not affect the chlorophyll, lipid, or carbohydrate content of the lettuce leaves. PCA (Principal Component Analysis) showed that soil pollution, fungicide application, and irrigation water quality are the most relevant factors determining the presence of contaminants in crops.Postprint (updated version

Aplicación de purin deshidratado como abono de fondo en una rotacion maiz-trigo :evolución del contenido de nitratos y nitrogeno orgánico en el horizonte superficial

Postprint (published version