•Negative impacts on the environment are a concern with specialized agriculture.•Soils rooted with perennial forages have high organic matter content.•High soil organic matter content contributes to ...high soil quality.•Improved soil quality with pasture–crop rotations can improve ecosystem services.•Review of science of pasture–crop rotations in temperate North and South America.
Agriculture has become increasingly specialized in response to political, regulatory, sociological, and economic pressures to meet market demands of an ever-larger food and fiber processing sector. However, there is a growing concern with specialized agricultural systems, because of increasingly negative responses on the environment from declining soil quality to eutrophication of water bodies and enhanced greenhouse gas emissions. Literature from North and South America was reviewed that showed (i) strong positive production outcomes of crops grown following pastures, (ii) enhancement of soil organic matter with perennial pastures, particularly in the surface soil, (iii) improvement in water infiltration and water quality, and (iv) synergies between crop and livestock systems in system-wide evaluations of production and environmental quality. Therefore, agricultural soils would benefit from the re-introduction of perennial grasses and legumes into the landscape (i.e. temporally and/or spatially) by regaining soil organic matter and strengthening their capacity for long-term productivity and environmental resiliency.
En el nonagésimo aniversario del fallecimiento de Miguel Lillo, el presente trabajo presenta una síntesis de la importancia de las contribuciones botánicas, generadas por una figura emblemática que ...representa a las Ciencias Naturales en la provincia de Tucumán, Argentina. Se realizó una búsqueda bibliográfica específica sobre Miguel Lillo, biografías y consulta de bases de datos en línea. Se da a conocer una lista de especies descriptas por Lillo validadas actualmente y taxones de plantas y hongos en honor a la memoria del gran sabio.
Virtual integration of sensor observation data Regueiro, Manuel A.; Viqueira, José R.R.; Taboada, José A. ...
Computers & geosciences,
August 2015, 2015-08-00, 20150801, Letnik:
81
Journal Article
Recenzirano
This paper discusses the design, implementation and evaluation of a framework that enables the virtual integration of heterogeneous observation data sources through a Sensor Observation Service (SOS) ...standard interface. Currently available SOS implementations follow a data warehouse design approach for data integration. Contrary to this, the present framework uses a well-known Mediator/Wrapper virtual data integration architecture, enabling the direct access to the current data supplied by the data sources. Currently, the framework is being validated as the OGC compliant technology to publish the meteorological and oceanographic observation data generated by two public agencies of the regional government of Galicia (Northwest of Spain).
•Virtual observation data integration vs. prevailing data warehouse approaches.•Flexible combination of Mediator/Wrapper architecture with OGC SWE interfaces.•In situ and remote static and mobile sensors producing vector and raster data.•Multi-thread implementation to leverage current hardware multicore architectures.•Under validation in two Spanish public meteorological and oceanographic agencies.
The objective of this study was to identify pore characteristics (quantity, distribution, stability and orientation of pores) that condition water dynamics under continuous zero tillage (ZT) on silty ...soils of the Argentinian Rolling Pampas. Soil properties were analyzed under continuous chisel plough (CP) and ZT treatments from three trials with different duration and crop sequence. The following soil properties of A horizon were analyzed from 0 to 0.05 and from 0.10 to 0.15
m depths: bulk density, pore size distribution, pore origin distribution, aggregate stability index, infiltration rate and organic matter. Preferred pore orientation was carried out by introducing the sampling cylinders in vertical and horizontal direction and then discriminating by pore size. Total porosity of A horizon under CP was 3.5% higher than under ZT. This could be attributed to macro and mesopores as well as to structural porosity. Aggregates were 30% more stable in ZT than under CP in the top at 0.05
m due to a 21% increase in organic matter. However, infiltration rate was not improved under ZT. Under ZT, there was a tendency of macropores to become orientated in parallel to the soil surface. This horizontal preferential macropore orientation was critical in determining water infiltration. The susceptibility to stratify the structure in the first centimeters of the soil under ZT was attributed to the predominance of soybean in the crop sequence.
In the humid Pampas of Argentina soybean is cultivated in different soil types, which were changed from conventional- to zero tillage systems in the last decade. Little is known about the response of ...soybean roots to these different soil physical environments. Pasture, and conventionally- and zero-tilled field lots cropped to soybean (R1 and R2 ontogenic stages) were sampled in February–March 2001 in a sandy clay loam and two silty clay loam Mollisols, and in a clayey Vertisol. In the 0–0.05
m layer of conventionally- and zero-tilled lots soil organic carbon represented 53–72% of that in pasture lots, and showed an incipient recovery after 4–11 years of continuous zero tillage. Soil aggregate stability was 10.1–46.8% lower in conventionally-tilled than in pasture lots, and recovered completely in zero-tilled lots. Soil relative compaction ranged 60.8–83.6%, which was below the threshold limit for crop yields (>90%). In change, soil porosity
>50
μm ranged 0.91–5.09% soil volume, well below the minimum critical limit for root aeration and elongation (>10%, v/v). The threshold of soil resistance (about 2–3
MPa) was only over passed in an induced plough pan in the conventionally-tilled Bragado soil (5.9
MPa), and in the conventionally- and zero-tilled Ramallo soils (3.7–4.2
MPa, respectively). However, neither the low macroporosity nor the high soil resistances impeded soybean roots growth in any site. According to a fitted polynomial function, root abundance was negatively related to clay content in the subsoil (
R
2
=
0.84,
P
<
0.001). Soybean roots were only abundant in the subsoil of the sandy clay loam Mollisol, which had <350
g
kg
−1 clay. Results show that subsoil properties, and not tillage systems, were the primary effect of root growth of soybean.
Over the last two decades, grazing intensity has increased in the temperate salt marshes of Samborombón Bay (Argentina) due to agricultural expansion and the displacement of domestic livestock to ...these areas. We investigated the effect of cattle grazing on soil chemical and physical properties in the higher (HE), medium (ME) and lower (LE) elevation levels of this temperate salt marsh. Soil data were collected from both a National Park, where cattle grazing has been excluded for more than 35 yrs, and an adjacent commercial livestock farm continuously grazed by cattle. We found that soil salinity was greater on the grazed than on the ungrazed sites, especially those in the ME and LE. This could be related to the upward flow of salts from the saline groundwater, driven by the increase in the proportion of bare soil on grazed sites. The increase in soil salinity changed the plant community structure through the increase of salt‐tolerant and non‐palatable species and the decrease of palatable species. Soil physical variables (soil bulk density and soil bearing capacity) were also higher on the grazed than on the ungrazed sites, which can be related to the decrease in soil organic matter (SOM), and suggest an incipient compaction process; however, the values were still lower than those considered critical for plant growth in clay soils. These results suggest that continuous grazing management in this temperate salt marsh might have negative consequences for animal production and ecosystem conservation, mainly related to the increased soil salinity. Further research will be necessary to evaluate the suitability of switching to intermittent grazing management.
SETTING: Galicia, Spain.OBJECTIVE: To describe changes in tuberculosis (TB) epidemiology and characteristics in Galicia, Spain, during the period 1996-2011.DESIGN: Retrospective observational ...descriptive study of data obtained from the Tuberculosis Information System.
The Galician Tuberculosis Prevention and Control Programme, created in 1994, is based in seven tuberculosis units that actively collect data on case finding and follow-up of all cases of TB in the region.RESULTS: TB incidence fell from 72.9 cases per 100 000 population in 1996 to
24.6 in 2011 (respectively 40.5 and 14.2 in patients aged <15 years). In 2011, 49.8% (n = 343) of patients were aged between 25-54 years; 62.3% (n = 429) were male; 52.1% (n = 359) had pulmonary TB (PTB) alone, of whom 33.5% (n = 144) had cavitary lesions;
50.7% (n = 218 PTB cases) were sputum smear-positive and 80.5% (346 PTB cases) were culture-positive. The median diagnostic delay was 56 days; 4.6% (n = 32) were human immunodeficiency virus positive and 5.2% (n = 36) were immigrants. The treatment success rate was close
to 90%. Contacts of 86.7% of the smear-positive index cases were evaluated.CONCLUSION: TB incidence in Galicia is progressively decreasing; however, it is still higher than that of neighbouring regions. A long diagnostic delay was observed, which may have contributed to the high incidence
rate in children.
Assuming a steady state between carbon (C) gains and losses, greenhouse gases (GHG) inventories that follow a widely used simplified procedure (IPCC Tier 1) tend to underestimate the capacity of ...soils in grazing-land to sequester C. In this study we compared the C balance reported by (i) national inventories that followed the simplified method (Tier 1) of IPCC (1996/2006), with (ii) an alternative estimation derived from the meta-analysis of science-based, peer-reviewed data. We used the global databases (i) EDGAR 4.2 to get data on GHG emissions due to land conversion and livestock/crop production, and (ii) HYDE 3.1 to obtain historical series on land-use/land cover (LULC). In terms of sequestration, our study was focused on C storage as soil organic carbon (SOC) in rural lands of four countries (Argentina, Brazil, Paraguay and Uruguay) within the so-called MERCOSUR region. Supported by a large body of scientific evidence, we hypothesized that C gains and losses in grazing lands are not in balance and that C gains tend to be higher than C losses at low livestock densities. We applied a two-way procedure to test our hypothesis: i) a theoretical one based on the annual conversion of belowground biomass into SOC; and ii) an empirical one supported by peer-reviewed data on SOC sequestration. Average figures from both methods were combined with LULC data to reassess the net C balance in the study countries. Our results show that grazing lands generate C surpluses that could not only offset rural emissions, but could also partially or totally offset the emissions of non-rural sectors. The potential of grazing lands to sequester and store soil C should be reconsidered in order to improve assessments in future GHG inventory reports.
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•Carbon sequestration in grasslands is reanalyzed due to inventory carbon miscounting.•Atmosphere-biosphere intersecting factors were studied to reassess carbon balance.•Theoretical and empirical data on carbon sequestration in grasslands were compared.•Carbon gains outweigh carbon losses in grasslands under extensive grazing conditions.•Reassessment of carbon sequestered in grassland soils is needed in inventory reports.
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•Al2O3-Ga2O3 solid solutions were obtained and resulted in high activity.•The Pd deposited resulted in metallic nanoparticles highly dispersed.•Gallium oxide content impact directly ...on the dehydration activity and selectivity.•The morphology of Pd nanoparticles resulted Ga2O3 content dependent.•The highest activity among series was observed over the Pd/AlGa-50 catalyst.
A series of mixed Al2O3-Ga2O3 oxides were prepared with different Ga2O3 content (labeled as AlGa-x; where x is the wt % of Ga2O3) by precipitation method. The oxides were then used as supports of palladium (2 wt %) catalysts (labeled as Pd/AlGa-x). Both series of samples, AlGa-x and Pd/AlGa-x were characterized by several techniques such as Raman spectroscopy, XPS, XRD, SEM, and HRTEM, and were tested in the 2-propanol dehydration reaction. The steady-state conversions displayed by the Pd/AlGa-x series was almost twice as that obtained for the AlGa-x series in all the range of tested temperatures. It was worth noting that the presence of palladium changed the yield observed for the AlGa-x series mainly at low temperatures. While at high temperatures the Lewis acidity provided by the well dispersed Pd nanoparticles increased the activity considerably and improved the propylene production. A balance between the dispersion of palladium and the surface acidity, both related to the Ga2O3 content was responsible for the observed catalytic behavior.
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