Use of biochar as peat substitute for growing substrates of Euphorbia × lomi potted plants

Biochar from conifers wood was used in soilless culture as growing substrate alternative to peat for ornamental crops. Potted plants of Euphorbia × lomi Rauh cv. 'Ilaria' were grown with different mixtures (v:v) of brown peat and biochar in order to evaluate main physical and chemical characteristics of this biomaterial as well as its effect on plant growth, ornamental characteristics and nutrients uptake. Biochar addition to peat increased pH, EC and K content of the growing substrates, as well as air content and bulk density. Biochar content of substrates significantly affected plant growth and biomass partitioning: higher number of shoots and leaves, leaf area and leaf dry weight were recorded in plants grown in 40% peat-60% biochar, with respect to plants grown in 100% peat and secondarily in 100% biochar. Leaf chlorophyll content was higher in plants grown in 60% and 80% biochar, while biomass water use efficiency was higher with 60% biochar. Plant uptake of K and Ca increased as biochar content of the substrates increased. Hence, a growing substrate containing 40% brown peat and 60% conifers wood biochar was identified as the more suitable mixture allowing to have a high-quality production of Euphorbia × lomi potted plants

Combined proton NMR wideline and NMR relaxometry to study SOM-water interactions of cation-treated soils

Focusing on the idea that multivalent cations affect SOM matrix and surface, we treated peat and soil samples by solutions of NaCl, CaCl2 or AlCl3. Water binding was characterized with low field 1H-NMR-relaxometry (20 MHz) and 1H wideline NMR spectroscopy (400 MHz) and compared to contact angles. From 1H wideline, we distinguished mobile water and water involved in water molecule bridges (WaMB). Large part of cation bridges (CaB) between SOM functional groups are associated with WaMB. Unexpectedly, 1H NMRrelaxometry relaxation rates suggest that cross-linking in the Al-containing peat is not stronger than that by Ca. The relation between percentage of mobile water and WaMB water in the context of wettability and 1H NMR relaxation times confirms that wettability controls the water film surrounding soil particles. Wettability is controlled by WaMB-CaB associations fixing hydrophilic functional groups in the SOM interior. This can lead to severe water repellency. Wettability decreases with increasing involvement of functional groups in CaB-WaMB associations. The results demonstrate the relevance of CaB and WaMB for the dynamics of biogeochemical and hydrological processes under field conditions, as only a few percent of organic matter can affect the physical, chemical, and biological functioning of the entire 3-phase ecosystem

Sustainable greenhouse horticulture in Europe

The European greenhouse horticulture represents one of the most intensive energy sector in agriculture and strongly contributes to increase the energy and environmental vulnerability within regions having a large greenhouse farming systems. Specifically, the European greenhouse farming sector is facing a trend that responds to the changing consumer’s demands in a society that, globally, is increasingly affluent but more aware about some negative consequences, such as high energy-demand processes, and CO2 emissions. About 200,000 hectares of greenhouses in Spain, Italy, The Netherlands and Greece is the estimated covered surface, with not less than 3.4 MTOE of energy consumption and 9.2 MtCO2eq, and an yearly economy value of 7 billions of Euros. The installed energy power load of greenhouses in Europe depends on local climate conditions, and varies from 50-150 W/m2 (Southern regions of Europe) to 200-280 W/m2 (Northern and Central regions), while complete conditioning could even reach an energy load of 400 W/m2 (heating, lighting, cooling). Nowadays, the proportion of renewable use in the total energy consumption of greenhouse farming in Europe is very low, and there are no clear priorities set in this area, yet. Comprehensive and complete studies that evaluate the opportunities of renewable options in greenhouse sector are still not completeted. This, strongly hinders the process of setting concrete goals and legislative targets to support a wider introduction of sustainable energy technology, and appropriate legislation in greenhouse regions of Europe. This paper deals with the proposal of supporting the organization of a sustainable greenhouse agriculture, based on renewable energy sources, i.e. geothermal energy at low temperature, photovoltaic solar energy and solid biomass, in tune with the specific local assets, the local geo-climatic conditions and the protection of landscapes rather than with a careless perspective for local environment and potential societal costs

Surface Morphology and Electrical Resistivity in Polycrystalline Au/Cu/Si(100) System

This work describes the analysis of morphology and electrical resistivity (ρ) obtained in the Au/Cu/Si system. The Au/Cu bilayers were deposited by thermal evaporation technique with thicknesses from 50 to 250 nm on SiOx/Si(100) substrates. The Au : Cu concentration ratio of the samples was of 25 : 75 at%. The bilayers were annealed into a vacuum oven with argon atmosphere at 660 K for one hour. The crystalline structures of AuCu and CuSi alloys were confirmed by X-ray diffraction analysis. The scanning electron microscopy (SEM), the atomic force microscopy (AFM), and the energy dispersive spectroscopy (EDS) were used to study the morphology, final thickness, and the atomic concentration of the alloys formed, respectively. The four-point probe technique was used to measure the electrical resistivity (ρ) in the prepared alloys as a function of thickness. The ρ value was measured and it was numerically compared with the Fuchs–Sondheimer (FS) and the Mayadas–Shatzkes (MS) models of resistivity. Results show values of electrical resistivity between 0.9 and 1.9 μΩ-cm. These values are four times smaller than the values of the AuCu systems reported in literature

Conformational behaviour of humic substances at different depths along a profile of a Lithosol under loblolly (Pinus taeda) plantation.

Published in 6th EGU General Assembly 2009

Developing Effluent Analysis Technologies to Support Nonproliferation Initiatives, Arms Control and Nonproliferation Technologies, Third quarter 1995

This issue provides an overview of the Effluent Research Program of the DOE Office of Research and Development, highlighting a number of representative projects within this program in support of nonproliferation initiatives. Technologies reported include portable instruments for on-site inspections, standoff detectors, fieldable, real-time instruments, field collection techniques, and ultrasensitive laboratory techniques

Comparative Leaf Water Absorption Between Chaparral Island and Mainland Taxa: a Common Garden Experiment

In California and other Mediterranean-type ecosystems, island species are typically exposed to more fog but less rain than mainland species. Because adaptations to absorb water from fog may conflict with those to minimize water loss, we hypothesized that island species should have greater fog absorption than their mainland congeners due to foliar uptake but at the cost of modifying other leaf structural and functional traits. To determine whether foliar water absorption is an adaptation to insularity, we compared seven physiological and anatomical leaf traits between congeneric island and mainland species of two genera, Ceanothus and Arctostaphylos, in a common garden in Claremont, California. We quantified leaf water potentials, maximum leaf water absorption rates, leaf hydrophobicity, leaf mass per area [LMA], succulence, stomatal density, and wax morphology. All taxa exhibited water permeability through their leaf surfaces, but only one of the three island taxa showed greater water absorption than their mainland counterparts. The island and mainland varieties of C. megacarpus were similar in water absorption and hydrophobicity, but the mainland variety had greater LMA, greater succulence, and thicker epicuticular wax. In Arctostaphylos, insularity promoted species-specific responses: A. catalinae had greater foliar absorption compared to the mainland species, whereas A. insularis displayed mesophytic traits such as hypostomatal morphology, horizontally oriented leaves and low LMA. Relative surface hydrophobicity was not linked to absorption rates, but the mainland species A. glauca had the most hydrophobic leaf surfaces in the study, achieved by their ornate epicuticular wax. Overall, island taxa displayed more mesophytic leaf traits than their mainland congeners. The results may have implications for biogeography in Mediterranean-type ecosystems that may be losing seasonal coastal fog with global change

Morphology evolution of thermally annealed polycrystalline thin films

Investigation of the morphology evolution of annealed polycrystalline Au(111) films by atomic force microscopy and x-ray diffraction leads to a continuous model that correlates such an evolution to local interactions between grains triggering different mechanisms of stress accommodation (grain zipping and shear strain) and relaxation (gap filling and grain rotation). The model takes into consideration findings concerning the in-plane reorientation of the grains during the coalescence to provide a comprehensive picture of the grain-size dependence of the interactions (underlying the origin of the growth stress in polycrystalline systems); and in particular it sheds light on the postcoalescence compressive stress as a consequence of the kinetic limitations for the reorientation of larger surface structuresThis paper was supported by the projects F1-54173 (bilateral program CSIC-Conacyt) 200960I182 (CSIC), and CCG10-UAM/MAT-5537 (DGUI-Comunidad de Madrid and Universidad Aut´onoma deMadrid). A.G.G. acknowledges the financial support of the MICINN Spanish Ministry under the project ESP2006-14282-C02-0

Bancos comunitarios de semillas y el uso de recompensas por servicios de conservación de la agrobiodiversidad: primeras experiencias de la Sierra de Cuchumatanes, Huehuetenango, Guatemala

Los cultivos de gran diversidad como el maíz, fríjol y papa incluyen muchas variedades de alto valor público nacional y global, aunque solo algunas tienen sus valores reconocidos por los mercados. Esto afecta el estado de conservación de las variedades. Una solución innovadora para este dilema de provisión de bienes públicos usa los conceptos probados de pagos por servicios ecosistémicos (PSE) y los aplica a la gestión de la agrobiodiversidad. Su aplicación en la Sierra de los Cuchumatanes, Huehuetenango en Guatemala se revela la importancia de los mecanismos de incentivos para apoyar la gestión de los recursos genéticos por las propias comunidades y las importantes funciones que los bancos comunitarios de semilla pueden desempeñar en este contexto

Plant height and hydraulic vulnerability to drought and cold

Understanding how plants survive drought and cold is increasingly important as plants worldwide experience dieback with drought in moist places and grow taller with warming in cold ones. Crucial in plant climate adaptation are the diameters of water-transporting conduits. Sampling 537 species across climate zones dominated by angiosperms, we find that plant size is unambiguously the main driver of conduit diameter variation. And because taller plants have wider conduits, and wider conduits within species are more vulnerable to conduction-blocking embolisms, taller conspecifics should be more vulnerable than shorter ones, a prediction we confirm with a plantation experiment. As a result, maximum plant size should be short under drought and cold, which cause embolism, or increase if these pressures relax. That conduit diameter and embolism vulnerability are inseparably related to plant size helps explain why factors that interact with conduit diameter, such as drought or warming, are altering plant heights worldwide