Característiques dels sòls de conreu de cereals de Catalunya i llur fertilització

Hom estudia els sòls més representatius de Catalunya dedicats al conreu de cereals, tot posant-hi de manifest una baixa fertilitat i una abundància de carbonats. S'inclou també un resum de les característiques més importants dels sòls naturals dels quals deriven els sòls agrícoles.This paper relates the yield of winter cereals to soil classes in Catalonia. The basic criteria for fertility is exposed and a summary of the most important properties of natural soils related with agricultural ones is included. Data from 50 agricultural soils show that the most common limitations to the growth are: low fertility and excessive carbonates.Se estudian los suelos más representativos de Cataluña dedicados al cultivo de cereales evidenciandose una baja fertilidad y su alto contenido en carbonatos. Se incluye un resumen de las características más importantes de los suelos naturales de los que proceden los suelos agrícolas

Detailed human risk assessment arising from groundwater contaminated by chlorinated hydrocarbons (DNAPLs)

Podeu consultar el llibre complet a: http://hdl.handle.net/2445/67430Human health risk assessment is the basis for groundwater contamination and remediation goals definitions. Chlorinated solvents have a high toxicity for humans, even at low concentrations, and are important soil and groundwater pollutants. The main objective of this work is to assess the human health risk derived of exposition to a contaminated groundwater using a commercial Risk Analysis model (RBCA) and taking into consideration different exposure factors. A case study was used. Some risk differences were observed using specific exposure factors in different countries, which were explained by differences in life style

Influencia del suelo en la nodulación (rhizobium japonicum) de la soja

Tesi de Llicenciatura per a la obtenció del Grau de Farmàcia. Facultat de Farmàcia. Universitat de Barcelona. Director: José Cardús Aguilar, 1980.Una de las líneas de investigación seguidas actualmente en el Departamento consiste en el estudio de suelos que tengan, o puedan tener un interés aplicativo. Con el presente trabajo se pretende,en el ámbito de aquella, realizar un estudio bibliográfico, en primer lugar, del conjunto de suelos de la región catalana,en el que.se incluya la correlacion que pudiera existir entre las denominaciones aplicadas por las tres clasificaciones generales de suelos más utilizadas

Optimization of a quality model for CCA industrial impregnation of Pinus radiata D. Don agricultural fencing stakes

Impregnation of agricultural fencing stakes (Pinus radiata D. Don) using wood preservative solutions, like chromated copper arsenate (CCA-C), a water soluble salt, to protect them from decay and insect damage was investigated through the method of global modeling. Experiments were conducted using a factorial design with replicates to reduce model variability and to adjust responses to the required technical properties. Levels at which variables must be set were studied: to reduce product variability, to minimize production costs, to desensitize wood regarding the influence of uncontrollable variables, to optimize productive process and to create a global product with a higher intrinsic quality. The proposed model optimizes product retention quality and minimizes product variability, while minimizing preservative's use. Experiments were carried out by controlling wood's humidity, vacuum process duration, time of applying pressure, and preservative solution concentration, in order to allow timber to maintain its anatomical structure unchanged over time. The results of this work may be used in the optimization of similar processes in industrial plants for Pinus radiata D. Don stakes preservation treatments in producing countries

Biodegradable chelate enhances the phytoextraction of copper by Oenothera picensis grown in copper-contaminated acid soils

Oenothera picensis plants grow in the acid soils contaminated by copper smelting in the coastal region of central Chile. We evaluated the effects of the biodegradable chelate MGDA on copper extraction by O. picensis and on leaching of copper through the soil profile, using an ex situ experiment with soil columns of varying heights. MGDA was applied in two doses, one month apart, at concentrations of 0 (control), 2, 6 and 10 mmol plant-1. MGDA application significantly increased biomass production and foliar concentration, permitting an effective increase in copper extraction, from 0.09 mg plant-1 in the control, to 1.3 mg plant-1 in the 6 and 10 mmol plant-1 treatments. With 10 mmol plant-1 of MGDA, the copper concentration in the leachate from the 30 cm columns was 20 times higher than in the control. For the 60 cm columns, copper concentration was 2 times higher than the control. It can be concluded that at increased soil depths, copper leaching would be minimal and that MGDA applications at the studied concentrations would not pose a high risk for leaching into groundwater. It can thus be stated that applications of MGDA are an effective and environmentally safe way to improve copper extraction by O. picensis in these soils

Biogeochemistry of Plane Trees as a Tool to Detect Atmospheric Pollution

The plane tree, which is a valuable tool to detect atmospheric pollution, is one of the most common trees in European cities. Soil and leaf samplings were carried out in Barcelona and its environs (NE Spain) to establish the soil-plant relationship.Dry and ashed leaves and soils were analyzed by Instrumental Neutron Activation Analysis and Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP/OES) at the ACTLABS laboratories in Ontario, Canada. Given that diesel is the main fuel used in vehicles in Europe, we sought to establish the role of diesel in atmospheric pollution. Diesel samples were obtained from service stations and analyzed after preconcentration using ICP/MS at the geochemistry laboratories of the University of Barcelona. The average content of diesel oil shows high values of Pb, Cu, Cr, Ag, Cd and Mn. High values of Pb, Cu, Au, Hg and Sb in leaves and soils were detected downtown and along main roadsoutside the city, whereas low levels of these elements were observed in rural areas

Processes controlling the fate of chloroethenes emanating from dnapl aged sources in river-aquifer contexts

This work dealt with the physical and biogeochemical processes that favored the natural attenuation of chloroethene plumes of aged sources located close to influent rivers in the presence of co-contaminants, such as nitrate and sulfate. Two working hypotheses were proposed: i) Reductive dechlorination is increased in areas where the river-aquifer relationship results in the groundwater dilution of electron acceptors, the reduction potential of which exceeds that of specific chloroethenes; ii) zones where silts predominate or where textural changes occur are zones in which biodegradation place preferentially takes place. A field site on a Quaternary alluvial aquifer at Torelló, Catalonia (Spain) was selected to validate these hypotheses. This aquifer is adjacent to an influent river and its redox conditions favor reductive dechlorination. The main findings showed that the low concentrations of nitrate and sulfate due to dilution caused by the input of surface water diminish the competition for electrons between microorganisms that reduce co-contaminants and chloroethenes. Under these conditions, the most bioavailable electron acceptors were PCE and metabolites, which meant that their biodegradation was favored. This led to the possibility of devising remediation strategies based on bioenhancing natural attenuation. The artificial recharge with water that is low in nitrates and sulfates may favor dechlorinating microorganisms if the redox conditions in the mixing water are sufficiently maintained as reducing and if there are nutrients, electron donors and carbon sources necessary for these microorganisms