Showing papers on "Soil compaction published in 2016"
TL;DR: The field-study at three sites within the largest sugarcane-producing region of Brazil found that simple, user-friendly strategies were as effective as more complex ones for identifying SQ changes and recommended using a small number of indicators to reflect chemical, physical and biological processes within the soil.
Abstract: Increasing demand for biofuel has intensified land-use change (LUC) for sugarcane (Saccharum officinarum) expansion in Brazil. Assessments of soil quality (SQ) response to this LUC are essential for quantifying and monitoring sustainability of sugarcane production over time. Since there is not a universal methodology for assessing SQ, we conducted a field-study at three sites within the largest sugarcane-producing region of Brazil to develop a SQ index (SQI). The most common LUC scenario (i.e., native vegetation to pasture to sugarcane) was evaluated using six SQI strategies with varying complexities. Thirty eight soil indicators were included in the total dataset. Two minimum datasets were selected: one using principal component analysis (7 indicators) and the other based on expert opinion (5 indicators). Non-linear scoring curves were used to interpret the indicator values. Weighted and non-weighted additive methods were used to combine individual indicator scores into an overall SQI. Long-term conversion from native vegetation to extensive pasture significantly decreased overall SQ. In contrast, conversion from pasture to sugarcane had no significant impact on overall SQ at the regional scale, but site-specific responses were found. In general, sugarcane production improved chemical attributes (i.e., higher macronutrient levels and lower soil acidity); however it has negative effects on physical and biological attributes (i.e., higher soil compaction and structural degradation as well as lower soil organic carbon (SOC), abundance and diversity of macrofauna and microbial activity). Overall, we found that simple, user-friendly strategies were as effective as more complex ones for identifying SQ changes. Therefore, as a protocol for SQ assessments in Brazilian sugarcane areas, we recommend using a small number of indicators (e.g., pH, P, K, Visual Evaluation of Soil Structure -VESS scores and SOC concentration) and proportional weighting to reflect chemical, physical and biological processes within the soil. Our SQ evaluations also suggest that current approaches for expanding Brazilian sugarcane production by converting degraded pasture land to cropland can be a sustainable strategy for meeting increasing biofuel demand. However, management practices that alleviate negative impacts on soil physical and biological indicators must be prioritized within sugarcane producing areas to prevent unintentional SQ degradation over time.
182 citations
TL;DR: In this article, a randomized block design trial at two sites on a well-structured clay soil in central Sweden was established, where two levels of compaction were created at both sites, in the following referred to as trafficked and control.
Abstract: Soil compaction by vehicular traffic modifies the pore structure and soil hydraulic properties. These changes potentially influence the occurrence of preferential flow, which so far has been little studied. Our aim was to study the effect of compaction on soil hydraulic and transport properties in subsoil. A randomized block design trial at two sites on a well-structured clay soil in central Sweden was established. Plots with two levels of compaction were created at both sites, in the following referred to as trafficked and control. The trafficked treatment was created by 4 passes track-by-track with a three-axle dumper with a maximum wheel load of 5.8 Mg. After one year, undisturbed soil columns (20 cm height × 20 cm diameter) from both trafficked and control plots at a depth of 30–50 cm were sampled. The columns were analyzed using X-ray CT imaging, together with measures of the degree of preferential transport derived from non-reactive tracer breakthrough curves and measurements of saturated hydraulic conductivity ( K s ) and air permeability at the field moisture content ( K a ). Although the traffic treatment did not cause any compaction effects at one of the two sites, it did result in significant reductions in saturated hydraulic conductivity, air permeability and number of macropores at the second site. At this site, the traffic also significantly reduced the strength of preferential flow, presumably due to compaction-induced disruption of macropore continuity. In apparent contrast, some previous studies have shown increases in the strength of preferential flow as a result of compaction. We propose a conceptual model to explain these apparently contradictory results, which suggests that preferential flow should be strongest at some intermediate level of compaction.
104 citations
TL;DR: In this article, the authors evaluated the efficiency of the least limiting water range in determining the influence of grazing intensities on soybean yield in an Oxisol managed in a long no-till, integrated soybean-beef cattle system.
Abstract: Crop-livestock integrated systems possess some uniqueness in soil and plant hydro-physical properties and processes. To obtain a better understanding of these systems, it is necessary to evaluate them with indices that take into account several attributes. Our study aimed to evaluate the efficiency of the least limiting water range in determining the influence of grazing intensities on soybean yield in an Oxisol managed in a long no-till, integrated soybean-beef cattle system. We evaluated an 11 year trial located in southern Brazil, with soybean summer cropping and black oat + Italian ryegrass winter grazing and different winter grazing intensities, namely intensive, moderate and no grazing. Intensive grazing only results in the most superficial soil layer compaction. Long-term moderate grazing, on the other hand, leads to intermediate compaction, not negatively affecting surface or subsurface soil physical properties. The least limiting water range is an inadequate indicator of soil physical quality in integrated soybean-beef cattle system, provided no direct relations with soybean yields. Under normal rainfall conditions, soybean yield depend mainly on rainfall amount and distribution, rather than on soil quality.
77 citations
TL;DR: The study shows that a land use and management system can be monitored if it degrades or maintains or improves the soil using key soil quality indicators, and significantly affected bulk density, soil acidity, and silt content.
Abstract: Understanding changes in soil quality resulting from land use and land management changes is important to design sustainable land management plans or interventions. This study evaluated the influence of land use and land cover (LULC) on key soil quality indicators (SQIs) within a small watershed (Jedeb) in the Blue Nile Basin of Ethiopia. Factor analysis based on principal component analysis (PCA) was used to determine different SQIs. Surface (0-15 cm) soil samples with four replications were collected from five main LULC types in the watershed (i.e., natural woody vegetation, plantation forest, grassland, cultivated land, and barren land) and at two elevation classes (upland and midland), and 13 soil properties were measured for each replicate. A factorial (2 × 5) multivariate analysis of variance (MANOVA) showed that LULC and altitude together significantly affected organic matter (OM) levels. However, LULC alone significantly affected bulk density and altitude alone significantly affected bulk density, soil acidity, and silt content. Afforestation of barren land with eucalypt trees can significantly increase the soil OM in the midland part but not in the upland part. Soils under grassland had a significantly higher bulk density than did soils under natural woody vegetation indicating that de-vegetation and conversion to grassland could lead to soil compaction. Thus, the historical LULC change in the Jedeb watershed has resulted in the loss of soil OM and increased soil compaction. The study shows that a land use and management system can be monitored if it degrades or maintains or improves the soil using key soil quality indicators.
53 citations
TL;DR: In this article, a model for prediction of vertical stress distribution at the rubber track-soil interface is presented, which provides realistic estimates of the vertical stress at the contact between rubber track and soil, thereby improving predictions of soil stress and compaction risks of rubber-tracked agricultural vehicles.
Abstract: Rubber-tracked vehicles are becoming increasingly popular in agriculture. Rubber-tracked undercarriage systems are typically fitted instead of tyres on heavy agricultural vehicles, with the aim of e.g. decreasing soil stress and soil compaction risks. Therefore, accurate prediction of soil stresses below rubber-tracked systems is important. Here, we present a model for prediction of vertical stress distribution at the rubber track–soil interface. In the model, the rubber-tracked undercarriage system consists of a front and rear wheel (idler and drive wheel) and a number of support rollers. The stress distribution in the longitudinal direction under a wheel or roller is described by harmonic oscillation, with the dynamic contact length being a function of wheel or roller diameter. In the lateral direction, the stress distribution is modelled by a linear function, with the maximum stress under the centre line of the track. Model input parameters include the load on the track, track width, track length (distance between front and rear axles), number of support rollers and wheel and roller diameter. The model, which is written in Visual Basic and implemented as a macro in an Excel spreadsheet, then computes the vertical stress at the rubber track–soil interface based on these inputs and the stress distribution generated in the contact area can be used to simulate soil stresses. The model provides realistic estimates of the vertical stress at the contact between rubber track and soil, thereby improving predictions of soil stress and the compaction risks of rubber-tracked agricultural vehicles.
39 citations
TL;DR: Bulk density, porosity, soil pH, EC, tree survival, height, shoot extension and chlorophyll content were measured for the 2014 and 2015 growing seasons and incorporation of 25% v/v compost consistently decreased bulk density to below-root restricting thresholds, resulting in improved tree growth.
30 citations
TL;DR: In this article, the development of biocrusts on the south and north-facing slopes of the soil mounds over three years was investigated, and the results emphasize the importance of the micro-geomorphology in the recovery of the affected ecosystem.
Abstract: A drought- induced massive shrub death event was observed in a semi-arid region of the Negev Desert, leaving bare soil mounds in place. Hypothesizing that the absence of shrubs would allow biocrust expansion to cover the bare soil mounds, we followed the development of biocrusts on the south and north-facing slopes of the soil mounds over three years. Only after six years, when the mounds were totally flattened, were the water infiltration capacity and soil compaction properties of the developing biocrusts similar to those of the surrounding mature biocrusts. The prokaryotic community structure was exposed by pyrosequencing of 16S rRNA gene amplicons. A principal component analysis indicated that the development of microbial community on the soil mounds was affected at multiple scales, including biocrust successional stage, seasonal effect and the micro-geomorphology of the mound (north vs. south slopes). While the phototroph community structure was most associated with the biocrust successional stage, the heterotroph community structure was mostly season-associated. Compared to the north slope, the south slope exhibited delayed development in all determined parameters; with the addition of lately observed establishment of new shrubs in this site, the results emphasize the importance of the micro-geomorphology in the recovery of the affected ecosystem.
28 citations
TL;DR: In this paper, the dry density ρ d and the water content w are controlled in relation to laboratory compaction tests using a representative sample at a certain compaction energy level CEL.
26 citations
TL;DR: In this article, the effect of three combine harvester traffic intensities on soil compaction and soybean (Glycine max L.) yields was compared in a Typic Argiudoll soil in the east of the Rolling Pampa region, Argentina.
24 citations
TL;DR: In this paper, the authors investigated the effect of catch cropping on the soil structure in the topsoil of a catch crop with large-grain legumes under different ploughless tillage conditions during catch crop seeding.
21 citations
TL;DR: In this article, the effects of thinning with biomass removal using progressively more soil manipulations were investigated in young ponderosa pine plantations, and the results indicated that thinning by itself with no subsoiling did not compact the soils, but increased growth rate of residual trees, although the periodic annual increment of basal area and volume was still higher in the control than other main-plot treatments.
TL;DR: In this article, an extensive laboratory tests conducted to determine the optimal percentage of quicklime to reduce the excessive moisture to the optimal of compaction, the degree of compactness achieved by mixing in comparison to the compacted untreated material and the methodology for conducting the mixture and the compaction on site.
TL;DR: In this paper, the combined effect of crop rotation, soil compaction, and insect pollination on yield formation and on the contribution of biological fixation to nitrogen acquisition of faba bean was investigated.
TL;DR: In this article, the root system density in an irrigated peach orchard from Dobrogea, Romania, using the trench technique was analyzed using soil properties and soil compaction induced by technological traffic.
Abstract: A b s t r a c t. The available information on root system in fully mature peach orchards in semi-arid regions is insufficient. This paper presents a study on the root system density in an irrigated peach orchard from Dobrogea, Romania, using the trench technique. The old orchard has clean cultivation in inter-row and in-row. The objectives of the study were to: test the hypothesis that the roots of fully mature peach trees occupy the whole soil volume; find out if root repulsive effect of adjacent plants occurred for the rootstocks and soil conditions; find relationships between root system and soil properties and analyse soil state trend. Some soil physical properties were significantly deteriorated in inter-row versus in-row, mainly due to soil compaction induced by technological traffic. Density of total roots was higher in-row than inter-row, but the differences were not significant. Root density decreased more intensely with soil depth than with distance from tree trunks. Root density correlated with some soil properties. No repulsive effect of the roots of adjacent peach trees was noted. The decrease of root density with distance from trunk can be used in optimising tree arrangement. The conclusions could also be used in countries with similar growth conditions. K e y w o r d s: Calcaro-Calcic Chernozem, generative rootstock, root distribution, soil properties, trench method
TL;DR: The hypothesis that the roots of trees planted within a certain layout occupy the whole soil space is tested, the spatial distribution of root density is described using the trench technique, and the rootedness of apricot is emphasized in this soil type.
Abstract: Information on the root system of fully mature apricot (Prunus armeniaca L.) orchards is scarce. This paper deals with the root system of apricot trees in a semi-arid region of Romania. The 15-year old orchard was established with Hungarian Best variety grafted on Constanta 14 generative rootstock. Sprinkler irrigation was applied under a mild water stress regime. The purpose of this paper was to: (1) test the hypothesis that the roots of trees planted within a certain layout occupy the whole soil space, (2) describe the spatial distribution of root density using the trench technique, and (3) emphasize the rootedness of apricot in this soil type. Soil samples were taken from both in row (IR) and inter-row (ITR) positions to determine soil properties. Some physical properties were deteriorated in ITR versus IR, mainly due to soil compaction induced by the technological traffic. The root density was almost similar in ITR and IR, decreasing with both soil depth and distance from the tree trunk, and stronger correlations were obtained with soil depth. The roots of apricot trees are mainly concentrated within 0.5 m depth and occupy the entire soil space between trees, showing the highest density at about 1 m from the tree trunk. No root avoidance for neighboring trees was found. The horizontal decrease in root density can be used in optimizing tree arrangement in orchards. Canopy shape, light penetration and groundcover management system are also important in this decision. The results could be used in countries with similar environments.
TL;DR: The proposed method exploits the capabilities of the spaceborne SAR Interferometry technique to detect and map the ground subsidence with unprecedented spatial and temporal coverage and highlights the effectiveness of the proposed procedure for the continuous monitoring of the soil resonant periods.
TL;DR: A lower number of root nodules was found in NT plots when compared to CT plots depicting that soil compaction in the NT plots negatively affected nodulation, however, a higher number of effective nodules were found inNT plots indicating that NT plots provided better rhizospheric conditions for nitrogen fixation and therefore, improved soil productivity.
TL;DR: In this paper, a 3D finite element analysis (FEA) was conducted using LS-DYNA to simulate the depth of influence for various impact rollers, and it was found that the width of the contact area between the drum and the soil primarily controls the depths of compaction.
Abstract: The use of impact rollers has increased for many decades due to its diverse advantages. However, the current lack of theoretical verification and research-based technical guidelines that can effectively describe the effect of impact rollers is probably the greatest deficiency in our ability to accurately predict the benefits of deep compaction provided by impact compaction rollers. The 3-D Finite Element Analysis (FEA) was conducted using LS-DYNA to simulate the depth of influence for various impact rollers. Results indicated that the width of the contact area between the drum and the soil primarily controls the depth of compaction. The softer the soil is, the deeper the roller sinks in the soil. Also, the wider the contact area is, the deeper the compaction depth is. Thereby, the depth of compaction is highly dependent upon the stiffness of the soil. It was found that the surface pressure controls the degree of compaction and the surface pressure of the impact rollers is higher than that of the cylindrical rollers due to the dynamic effect. However, the distribution of the pressure is significantly variable for the impact rollers than the cylindrical rollers. It was concluded that the impact rollers seem to have more potential for use in final compaction of thicker layers.
1 Jan 2016
TL;DR: In this article, a ground-penetrating radar (GPR) study was conducted in an area under different management with soils formed in old alluvium and fluviomarine sediments (Ultisols).
Abstract: New Jersey, like many states in the northeastern USA, has a high demand for grazing land for horses. Grazing lands are often intensively used because of the limited possibilities for crop rotation. A ground-penetrating radar (GPR) study was conducted in an area under different management with soils formed in old alluvium and fluviomarine sediments (Ultisols). In the grazing field, no significant signs of compaction were detected with GPR. In the feeding fields, compaction was significant within 24 cm soil from the soil surface. The GPR data were used to generate a contour map representing the depth to the compacted layer. It is concluded that soil compaction can be adequately mapped using GPR.
22 Aug 2016
TL;DR: In this article, the effect of sheep-grazing intensity using piospheres on the structure of the vegetation and soil in shrubby steppes of Peninsula Valdes, Argentina was evaluated.
Abstract: The introduction of domestic livestock in the arid Patagonia produced changes in vegetation and soil that altered fundamental ecosystem processes, increasing desertification and biodiversity loss. In this region, it is common to observe gradients of decreasing animal activity from watering points where livestock impact is greatest near the watering sites, called piospheres, particularly suitable for assessing the effect of grazing on arid ecosystems. The aim of this study was to evaluate the effect of sheep-grazing intensity using piospheres on the structure of the vegetation and soil in shrubby steppes of Peninsula Valdes, Argentina. Variation of plant cover, vertical complexity of the vegetation, number and area of vegetated patches, micro-topography and soil compaction in relation to piosphere gradients were studied using Generalized Linear Mixed Models (GLMM) and multivariate analyses. Grazing intensity decreased according to increasing distance to the watering point. This fact, explaining more than 50% of the overall environmental variability, confirmed the existence of a piosphere gradient on each studied site. Such environmental changes were characterized by a gradual increase in grass and litter cover, vertical complexity of vegetation and soil microtopography at increasing distances from the watering point. Percentages of bare soil and gravel, cover of annual grasses and soil compaction showed the opposite pattern. This study demonstrates, for the first time, the existence of sheep piospheres in the shrubby steppes of Peninsula Valdes. Our results indicate that sheep-grazing intensity is associated with changes in the structure and composition of the vegetation and the soil characteristics that are compatible with degradation processes in the study region. Taking into account the importance of Peninsula Valdes in the context of biodiversity conservation, more studies of this type are required to implement effective management actions integrating livestock and conservation efforts on the terrestrial ecosystems of the region.
TL;DR: In this article, analytical and numerical solutions are provided for the problem of the interaction between compaction piles and a foundation slab and a surrounding soil cylinder that rests on an incompressible bed, with due regard for the potential expansion of the pile shaft.
Abstract: Analytical and numerical solutions are provided for the problem of the interaction between compaction piles and a foundation slab and a surrounding soil cylinder that rests on an incompressible bed, with due regard for the potential expansion of the pile shaft. Closed solutions are obtained for determining stresses in the pile shaft and the soil under a foundation slab in an end bearing pile scheme. This issue is most immediate for transforming beds using drain piles composed of a sand-gravel mixture.
TL;DR: In this paper, the authors present selected test results obtained during construction of multi-layer soil embankments, which allow for the assessment of the influence of compaction of the higher layers on the increased soil compaction in the lower layers.
Abstract: The paper presents selected test results obtained during construction of multi-layer soil embankments. It also provides the analysis of a new geotechnical approach, used for construction of non-typical soil embankments, which takes into account the effect of additional compaction of individual layers. The tests were conducted in in-situ conditions. The testing area constituted a foundation for a large industrial object, i.e. a clinker storage silo of storage capacity of 200 000 tons. The obtained results allow for the assessment of the influence of compaction of the higher layers on the increased soil compaction of the lower layers.
1 Jan 2016
TL;DR: The use of heavy machinery in agriculture is a major cause of compaction which, alters soil aggregate and pore structure affecting soil strength, porosity/availability of air and its response to heat as discussed by the authors.
Abstract: . The use of heavy machinery in agriculture is a major cause of compaction which, alters soil aggregate and pore structure affecting soil strength, porosity/availability of air and its response to heat. Compacted soils can lead to reductions in water and fertiliser uptakes leading to lower crop production and increased water runoff. Nutrient losses have been found to increase in compacted soil. A long-term 3x3 factorial Traffic (Random Traffic Farming, Controlled Traffic Farming and Low Ground Pressure systems) and Tillage (Deep, 250mm; Shallow, 100mm and no till) field trial at Harper Adams University, UK, was established in 2011. Initial results indicated benefits to crop yields from both Controlled Traffic Farming and Low Ground Pressure systems especially when applied under shallow tillage systems. An investigation was carried out in 2015 to determine whether the trial treatments had an effect on winter barley early growth and final yield by comparing components of yield at GS 30 and at harvest. Results for early growth found reductions in plant establishment and root dry mass for compacted areas possibly due to anaerobic conditions due to reduced soil pore size, however, the Barley yields were not significantly different (p>0.1). The compensation by the barley crop for the reduced plant numbers was by increased tiller survival and is thought to be due to the lower annual rainfall (22% reduction compared to the previous three year mean) especially during grain filling (33% reduction) which allowed sufficient soil moisture for optimum crop growth whilst sufficient soil pore air was maintained.
TL;DR: In this article, the authors investigated soil structures and several soil physical and mechanical properties associated with different failure patterns in two agricultural soils (upland and paddy) and found that brittle failure is the most desirable type of soil failure pattern to achieve appropriate tilth.
TL;DR: The results show increased survival of seedlings grown under low PPF and high water availability, which support the hypothesis of facilitation, which considers that under drought conditions the promoting effect of water balance induced by the shade is more positive for the survival of the seedlings.
Abstract: We examined the effect of abiotic characteristics (soil compaction, water availability and photosynthetic photon flux density (PPF) on the germination, emergence, growth and survival of Quercus ilex subsp. ballota seedlings. To determine the importance of these characteristics on the growth and development of the seedlings, we simulated two levels of water availability [650 mm year−1 (W650) and 1000 mm year−1 (W1000)], two levels of light [representing full (PPF100) and low sunlight (80 % reduction of sunlight, PPF20) conditions] and three soil compaction depths [soil compaction at depth 60 cm (C60), 25 cm (C25) and 10 cm (C10)]. Seedling emergence and survival were determined, along with various biometric characteristics. Emergence rate was only significantly affected by the water availability treatment, being significantly lower in W650. No differences were found in the other treatments. Seedlings grown under high PPF presented an increase in biomass. Seedlings grown in the deeper soils (C60) showed deeper and thinner roots. The results show increased survival of seedlings grown under low PPF and high water availability. Our results obtained in this greenhouse study support the hypothesis of facilitation, which considers that under drought conditions the promoting effect of water balance induced by the shade is more positive for the survival of the seedlings. We cannot say whether there are one or more independent factors that will limit or enhance the natural regeneration of Q. ilex, which implies that the effects of some can be mitigated, compensated for or amplified depending on the interaction with other elements. Knowledge of these interactions and the environmental variability of habitats at a smaller scale can be a powerful tool for promoting the growth of native vegetation and conservation of the Mediterranean area and dry environments.
TL;DR: In this paper, the effects of varying compaction and water availability levels on the growth of Berseem or Egyptian clover ( Trifolium alexandrimum L.), water use efficiency and nutrient concentration were investigated under greenhouse conditions.
Abstract: Soil compaction and insufficient water supply generally decrease crop performance. The effects of varying compaction and water availability levels on the growth of Berseem or Egyptian clover ( Trifolium alexandrimum L.), water use efficiency and nutrient concentration were investigated under greenhouse conditions. Treatments consisted of three soil compaction levels (bulk density of 1.2, 1.4 and 1.6 Mg m -3 ), and four water availability treatments (40%, 60%, 80% and 100% of soil field capacity) in a factorial combination. Soil compaction had a significant effect on water use efficiency with the highest (0.32 g l -1 ) at bulk density of 1.4 Mg m -3 and the lowest at the other bulk densities. Soil compaction had no significant effects on leaf area, shoot, root and total dry masses. Water stress resulted in lower leaf area (from 231 to 153 mm 2 pot -1 ), and the stem lengths were 7.6 cm and 4.3 cm for 80% and 60% of field capacity, respectively. Likewise, the highest (0.47 g pot -1 ) and lowest (0.33 g pot -1 ) total dry masses were observed at 80% and 60% field capacities. Water use efficiencies were 0.32 and 0.20 g l -1 for 100% and 60% field capacities, respectively. The accumulation of N, P and K per unit length of roots increased with soil compaction. As the water supply increased, the root and shoot dry weight and water use efficiency increased. Treatment of 100% field capacity resulted in the highest accumulation of N, P and K. Results indicated that the treatment of 80% field capacity and bulk density of 1.4 Mg m -3 provided the best conditions for clover performance, among the applied treatments. This study suggests that sufficient water supply can moderate the adverse effects of soil compaction on clover performance.
1 Jan 2016
TL;DR: In this article, an experiment was conducted to ascertain the effect of different types of black polyethylene mulches of varying thickness for its mechanical properties during crop growing period under onion.
Abstract: The use of plastic materials for mulching is a very common practice for horticultural crops. Black polyethylene is widely used due to its excellent properties and low cost. An experiment was conducted to ascertain the effect of different types of black polyethylene mulches of varying thickness for its mechanical properties during crop growing period under onion. Changes in tensile strength, elongation at break and tear resistance varied from 24.17 % to 74.82 %, 30.18% to 78.21 % and 19.45 to 60.68 % respectively within different thickness of plastic mulch during the entire duration of the crop. Poly-mulch made of recycled material (50 µm) underwent early deterioration which ultimately affected yield and growth of the crop. Other mulches remained functional during use, although its impact on soil compaction, soil temperature and soil moisture availability differed in narrow range but
TL;DR: In this paper, the ground vibration was measured by using a four channel seismograph in the open trench and for the trench filled with locally available waste material such as rice husk and bottom ash.
Abstract: The vibration generated by construction activities is transferred through soil media to the surroundings and has influence on the surrounding structures. However, the response of the structures may depend on the amount of energy received by them. The objective of this study is to investigate the characteristics of ground vibration induced by soil roller compaction and the effectiveness of waste material in reducing the propagation of the ground vibration. Several construction sites where soil compaction has been done by rollers were selected for this study. A site with a stone crushing machine which induces ground vibration similar to roller compaction (i.e., frequency and magnitude) was selected for the investigation of the effectiveness of waste material in reducing the propagation of ground vibration. A trench was introduced in the path of vibration wave propagation. The ground vibration was measured by using a four channel seismograph in the open trench and for the trench filled with locally available waste material such as rice husk and bottom ash. When operating a soil roller compactor, ground vibration in the horizontal directions (i.e., transverse and longitudinal directions)are greater than those in the vertical direction. Rice husk, compacted rice husk and bottom ash contributed to the reduction of ground vibration by 38%, 42% and 49% respectively in the transverse direction and by 14 %, 22 %, and 47 %, respectively in the longitudinal direction indicating that rice husk and bottom ash can be effectively used as in-filled damping layers.
TL;DR: In this article, the effect of mechanized forest harvesting operations on a Dystric Cambisol (Humic) with high organic matter (more 50 g kg1) content and exchangeable Al (more 6,0 cmolc kg-1), reforested with Pinus taeda L. The evaluated harvesting system were the whole-tree, in which the feller-buncher cuts and lays the trees down in bundles; the skidder drags the tree bundles up near a road; and the harvester delimbs and cuts the trees into short logs
Abstract: Traffic of heavy machinery at harvest and log extraction causes structural degradation of the soil, but studies on the effects of forest harvesting on soils with high organic matter content and exchangeable Al are scarce. The objective of this study was to evaluate the effect of mechanized forest harvesting operations on a Dystric Cambisol (Humic) with high organic matter (more 50 g kg1) content and exchangeable Al (more 6,0 cmolc kg-1), reforested with Pinus taeda L. The evaluated harvesting system were the whole-tree, in which the feller-buncher cuts and lays the trees down in bundles; the skidder drags the tree bundles up near a road; and the harvester delimbs and cuts the trees into short logs, stacking them on the roadside to be loaded onto trucks. The areas were evaluated for soil conditions at pre-harvest, prior to harvest, and at post-harvest, consisting of areas of low disturbance, high disturbance, forest residues and log yards. The effects of compaction after forest harvesting are observed by the decrease in total porosity (especially biopores and macropores), soil saturated hydraulic conductivity, and stability of aggregates. After forest harvesting, soil compaction was observed in all evaluated situations, but with different depths depending on operation type and the intensity of traffic carried in each area.