Search results for "040103 agronomy & agriculture"
showing 10 items of 794 documents
Determining Soil Hydraulic Properties Using Infiltrometer Techniques: An Assessment of Temporal Variability in a Long-Term Experiment under Minimum- …
2020
Conservation agriculture is increasingly accepted by farmers, but the modeling studies on agro-environmental processes that characterize these agricultural systems require accurate information on the temporal variability of the soil&rsquo
Spatiotemporal Variations in the Abundance and Structure of Denitrifier Communities in Sediments Differing in Nitrate Content
2017
Spatial and temporal variations related to hydric seasonality in abundance and diversity of denitrifier communities were examined in sediments taken from two sites differing in nitrate concentration along a stream Doñ
Transformation of clay-sized minerals in soils exposed to prolonged regular alternation of redox conditions
2016
Abstract The direction of the transformation of Fe-bearing minerals under harshly changing redox conditions is still under debate. Some studies suggest preferential accumulation of weakly crystalline Fe oxides while other studies showed that repeated redox cycles favour the presence of crystalline phases. Since characterized by distinct redox cycles, paddy soils are ideal for studying redox-related transformations of Fe oxides and Fe-bearing clay minerals. We analysed changes in the Fe mineral assemblage upon long-term reduction–oxidation cycles along a chronosequence of 100, 700, and 2000-year-old paddy soils developed on comparable parent material relative to two non-irrigated counterpart…
Stakeholders' Perceptions about Fire Impacts on Lithuanian Protected Areas
2014
The aim of this work is to study Lithuanian stakeholders' perceptions of fire impacts in protected areas. For this study, the stakeholders consisted of foresters, ecologists and farmers. A clear understanding of the opinions of stakeholders about fire effects on environmental, social and economic aspects of Lithuanian protected areas will allow an assessment of the stakeholders' reaction to fire policy, including government measures towards fire prevention, suppression and application of prescribed fire to landscape management. The results showed that stakeholders in general think that fire is not a threat to Lithuania and to the ecological processes in the protected areas. However, they ag…
Response of soil bacteria to Hg (II) in relation to soil characteristics and cell location
2006
The response of indigenous bacterial communities to the addition of inorganic mercury (50 μM of Hg(II)) was compared over a 30 day period in four soils of contrasting properties. Hg(II) impact was estimated by following population dynamics of viable heterotrophic bacteria (VH) and mercury resistant bacteria (HgR) by indirect enumeration in unfractionated soil and in the inner and outer parts of soil aggregates obtained by successive washings. Numbers of VH bacteria in unfractionated soils were not affected by mercury in any of the studied soils, whereas an increase in resistant bacteria was observed in all of them. The lag phase before the increase of HgR bacteria and the magnitude of the e…
High emissions of greenhouse gases from grasslands on peat and other organic soils
2016
Drainage has turned peatlands from a carbon sink into one of the world's largest greenhouse gas (GHG) sources from cultivated soils. We analyzed a unique data set (12 peatlands, 48 sites and 122 annual budgets) of mainly unpublished GHG emissions from grasslands on bog and fen peat as well as other soils rich in soil organic carbon (SOC) in Germany. Emissions and environmental variables were measured with identical methods. Site-averaged GHG budgets were surprisingly variable (29.2 ± 17.4 t CO2 -eq. ha-1 yr-1 ) and partially higher than all published data and the IPCC default emission factors for GHG inventories. Generally, CO2 (27.7 ± 17.3 t CO2 ha-1 yr-1 ) dominated the GHG budget. Nit…
Assessment of the interpretability of data mining for the spatial modelling of water erosion using game theory
2021
Abstract This study undertook a comprehensive application of 15 data mining (DM) models, most of which have, thus far, not been commonly used in environmental sciences, to predict land susceptibility to water erosion hazard in the Kahorestan catchment, southern Iran. The DM models were BGLM, BGAM, Cforest, CITree, GAMS, LRSS, NCPQR, PLS, PLSGLM, QR, RLM, SGB, SVM, BCART and BTR. We identified 18 factors usually considered as key controls for water erosion, comprising 10 factors extracted from a digital elevation model (DEM), three indices extracted from Landsat 8 images, a sediment connectivity index (SCI) and three other intrinsic factors. Three indicators consisting of MAE, MBE, RMSE, and…
Effects of the herbicides Benzoylpropethyl and flampropisopropyl on rat liver mitochondria : an alteration in membrane fluidity ?
1984
Abstract The action of the herbicides benzoylpropethyl and flampropisopropyl, and the corresponding unesterified acids was studied in rat liver mitochondria. The herbicides were found to (a) inhibit the mitochondrial electron transfer in complex III or at the level of ubiquinone (I50 of 4 nmol mg protein−1 for flampropisopropyl and 18 for benzoylpropethyl with succinate as a substrate); (b) have an additional (however less sensitive) site of inhibition near succinate dehydrogenase; and (c) interfere with energy transfer. Sensitivity was increased 2- (benzoylpropethyl) and 3.5-fold (flampropisopropyl) as the rats age increased from 12–13 weeks to 23–26 weeks. The free acids were far less eff…
Assessing soil contamination and temporal trends of heavy metal contents in greenhouses on semiarid land
2018
Information about the behavior and temporal evolution of heavy metals in agricultural soils is limited, particularly about greenhouse soils on semiarid lands, indeed it nonexistent. Western Almería (Southern Spain) is a semiarid land where some 30,000 ha are occupied by greenhouses with high productivity. As these greenhouses are fundamental to the socioeconomic development of this area, they should be maintained and well conserved. However, there are indications that long-term intensive agriculture with considerable agrochemicals use can deteriorate soil quality, which in turn, would reduce productivity and food quality. This study was conducted to investigate soil contamination and the te…
Monitoring soil volume wetness in heterogeneous soils by electrical resistivity. A field-based pedotransfer function.: A field-based pedotransfer fun…
2014
11 pages; International audience; Modern irrigation techniques require accurate, rapid, cost-effective, spatial measurement of soil moisture. Electrical Resistivity Tomography (ERT) meets most of these requirements, but needs to be calibrated for each use because it is very sensitive to differences in soil characteristics. In this study, a pedotransfer function approach is used to remove the need for site-specific calibration, allowing ERT to be used directly to measure soil moisture. The study site was a hillslope vineyard, where eight calcaric-cambisol soil profiles were identified. From 2012 to 2013, 23 000 soil volume wetness measurements were acquired by Time Domain Reflectometry, and …