Search results for "Loam"
showing 10 items of 76 documents
Ring diameter effects on determination of field-saturated hydraulic conductivity of different loam soils
2017
Abstract Establishing ring diameter effects on the field-saturated soil hydraulic conductivity, Kfs, determined with ponding infiltrometer methods can help to find a compromise between the need to sample a large area with an individual measurement and the impracticality of using large rings in the field. Five ring sizes (diameter, D = 5.5, 10.9, 16.0, 27.8 and 31.8 cm) were used to determine Kfs by the simplified falling head (SFH) technique in four loamy soils with different salinity (electrical conductivity of saturated extract, ECe = 0.9–29.4 dS/m) and sodicity (exchangeable sodium percentage, ESP = 2.7–81.3%) levels. According to USDA classification, two soils were non-saline, non-sodic…
Use of sonication for measuring acid phosphatase activity in soil
2000
Extracellular enzymes in soil often occur in immobilised forms, a state that may alter their interactions with substrates in comparison with enzymes in the solution phase. Sonication was evaluated for its usefulness in studying immobilised acid phosphatase by dispersing soil aggregates. Factors affecting soil dispersion during ultrasound application were soil extraction ratio, total applied energy and power output ml−1 of sonicated soil slurry. For the clay loam soil used, optimal values for these variables were, respectively, 1:6 (w/v) and, at least, 1800 J ml−1 and 15 W ml−1. At the optimal sonication conditions for soil dispersion a substantial increase in phosphatase activity (up to 156…
The impact of organic amendments on soil hydrology, structure and microbial respiration in semiarid lands
2016
Abstract Few studies have considered the effect of organic amendments on soil microbial activity and its contributions to hydraulic conductivity under field conditions in semiarid region soils with different textures and degrees of aggregate stability. This study was performed to investigate the relationship between selected soil properties and hydraulic conductivity in response to different types and application rates of organic amendments. For this purpose, urban municipal solid waste (MSW) compost and alfalfa residue (AR) were applied at different rates of 0 (control), 10 Mg ha− 1 and 30 Mg ha− 1 to clay loam and loamy sand soils under field conditions. Results show that after two years,…
«I Do Not Understand the United States» Exploring why the gun issue is still so controversial, and why it is so difficult to enforce meaningful legis…
2020
Master´s thesis in English (EN501)
Investigating the Teaching and Learning of British and American Culture in Norwegian Upper Secondary School
2021
Master´s thesis in English (EN501) This thesis is an investigation of teachers’ influence on pupils related to cultural knowledge in upper secondary. A semi-structured interview with three teachers provide data that is compared with a survey questionnaire among their pupils. The main emphasis has been on British and American culture because of the standing in Norway. An essential factor is that the Norwegian curriculum is in the process of implementation. This fact created a need to consider changes to the curriculum because these changes may influence teaching and findings. Therefore the cultural theme’s position in the curriculum is presented with some historical developments. The researc…
Short-term changes in infiltration between straw mulched and non-mulched soils after wildfire in Mediterranean forest ecosystems
2018
Abstract Water infiltration is a basic parameter to understand the hydrological response of semi-arid or arid soils – where runoff generation is dominated by infiltration-excess – subjected to wildfire. To evaluate the hydrological effects of straw application on a sandy loam soil after wildfire, the unsaturated hydraulic conductivity, water content and temperature of mulched and nonmulched (considered as control) soils were monitored throughout eight months. Compared to untreated soils, straw maintained higher temperatures and water contents in mulched plots, but reduced their unsaturated hydraulic conductivity, particularly in the drier season. These results suggest that straw release may…
Transfer of hexazinone and glyphosate through undisturbed soil columns in soils under Christmas tree cultivation.
2004
Abstract Field studies monitoring pesticide pollution in the Morvan region (France) have revealed surface water contamination by some herbicides. The purpose of this study was to investigate in greater detail the transport of two herbicides, used in Christmas tree production in the Morvan, under controlled laboratory conditions. Thus, the leaching of hexazinone (3-cyclohexyl-6-dimethyl-amino-1-methyl-1,3,5-triazine-2,4 (1H,3H) dione) and glyphosate ( N -(phosphono-methyl-glycine)) through structured soil columns was studied using one loamy sand and two sandy loams from sites currently under Christmas tree cultivation in the Morvan. The three soils were cultivated sandy brunisol [Sound refer…
Analysis of Chemical and Biochemical Parameters of Petrol-Contaminated Soil after Biostimulation with an Enzyme Reagent
2020
This study aimed to assess the effect of petrol and the Fyre Zyme reagent on selected chemical and biochemical properties of loamy sand. The experiment was conducted under laboratory conditions. First, petrol was introduced into the soil at doses of 0 and 50 g k-1dry matter (DM). Next, 6% Fyre-Zyme enzyme reagent solution was added to the samples contaminated and uncontaminated with petrol, in the following combinations: 0 (control), once at 40 cm3 kg&ndash
The effects of woodchip- and straw-derived biochars on the persistence of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA) in soils
2014
Sorption and degradation are the primary processes controlling the efficacy and runoff contamination risk of agrochemicals. This study assessed the influence of two biochars, made from woodchips and straw at a pyrolysis temperature of 725°C and applied to a loamy sand and a sandy soil in the concentration of 5.3 g 100 g(-1) sandy soil and 4.1 g 100 g(-1) loamy sand soil, or 53 t ha(-1) for both soil types, on degradation of the herbicide 4-chloro-2-methylphenoxyacetic acid (MCPA). Soils were spiked with 50 mg MCPA kg(-1) soil. In the sandy soil, significantly more MCPA remained after 100 days if amended with straw-derived biochar in comparison to wood-derived biochar. Both biochars types si…
Budgeting soil erosion from floodplain sediments of the central Rhenish Slate Mountains (Westerwald), Germany
2011
The distribution, thickness and composition of the floodplain sediments in the valleys of the Gelbach (Lower Westerwald) and Große Nister (Upper Westerwald) depend on the occurrence of loessic periglacial cover beds in their catchments as well as on historical land use. The budget of floodplain sedimentation was derived from a study of the floodloams underlying the monastery garden of Marienstatt, a village in the Große Nister valley. From the study of two occupation levels, pottery shards and radiocarbon dating, 55% of the floodloam can be attributed to the Modern period (younger than c. AD 1450). From the radiocarbon age of a charcoal fragment extracted from the base of the floodloam at …