Abstract: Soil compaction adversely influences most terrestrial ecosystem services on which humans depend. This global problem, affecting over 68 million ha of agricultural land alone, is a major driver of soil erosion, increases flood frequency and reduces groundwater recharge. Agricultural soil compaction has been intensively studied, but there are no systematic studies investigating the extent of compaction in urban ecosystems, despite the repercussions for ecosystem function. Urban areas are the fastest growing land-use type globally, and are often assumed to have highly compacted soils with compromised functionality. Here, we use bulk density (BD) measurements, taken to 14 cm depth at a citywide scale, to compare the extent of surface soil compaction between different urban greenspace classes and agricultural soils. Urban soils had a wider BD range than agricultural soils, but were significantly less compacted, with 12 per cent lower mean BD to 7 cm depth. Urban soil BD was lowest under trees and shrubs and highest under herbaceous vegetation (e.g. lawns). BD values were similar to many semi-natural habitats, particularly those underlying woody vegetation. These results establish that, across a typical UK city, urban soils were in better physical condition than agricultural soils and can contribute to ecosystem service provision.

Abstract: Crop establishment depends primarily on the methods used for seedbed preparation and sowing. Our main objective was to evaluate the soil compaction and crop residue effects on maize ( Zea mays L.) seedling emergence and yields in three tillage regimes: direct sowing (DS), chisel plough (ChP) and mouldboard plough (MP). The current study was performed in the eastern section of the humid subtropical Rolling Pampa region, Buenos Aires State (Argentina) between October 2004 and March 2007. The soil of the study site is a typical Argiudoll. We hypothesised that maize yields are affected by different tillage regimes used for seedbed preparation and that the traffic for the three tillage regimes caused subsoil compaction. The variables measured were: (1) cone index (CI) in the 0–450 mm depth profile; (2) root dry matter per plant (RDM); (3) dry matter per plant (DMP); (4) seedling emergence (SE); and (5) maize yields (MY). The results showed that in DS, the high soil compaction level causes smaller yields (decrease between 10.7 and 15.2%) compared with the other two tillage systems. SE was slower under ChP and MP compared with DS, but similar results were achieved 18 days after sowing. The highest RDM average values for three growing seasons were observed in ChP and MP (42.3 and 46.1 g plant −1 , respectively) compared to DS (37.1 g plant −1 ). The study produced the following conclusions. Maize yield was directly related to root dry matter per plant, which was affected by soil compaction. The soil Ap horizon needs to be tilled to improve yields. Despite the greater number of tractor passes in ChP and MP, all systems caused subsoil compaction. SE was not affected by plant residue.

Abstract: Subsoil compaction is a recognised threat in the European Soil Strategy and knowledge concerning the vulnerability of subsoils to compaction in Europe and the Netherlands is information required for the determination of priority areas (or risk areas) in the future European Soil Framework Directive. In Europe two risk assessment methods (RAM) are used in more than one country to determine the subsoil compaction risk. The first one (RAM-A) initially determines the susceptibility of soils to compaction as a function of texture and packing density. In the second step the vulnerability to compaction is determined as a function of susceptibility and climate. The second RAM (RAM-B) is a mechanistic model in which the soil mechanical strength determines whether a subsoil is susceptible to compaction. The RAMs are used to produce maps presenting the susceptibility and vulnerability to compaction of Dutch subsoils (RAM-A) and maps with the compression strength and maximal allowable wheel load of a Terra Tire to prevent compaction of Dutch subsoils (RAM-B). Both RAMs have weaknesses. RAM-A is an expert model and can be rather arbitrarily with results that are not in agreement with our experience. RAM-B suffers from lack of good data and probably underestimates subsoil strengths. Results of both RAMs are compared to each other and to a map showing the probability that the subsoil is already overcompacted. This probability map is based on bulk density data in the Dutch Soil Database (BIS). There is a good match between the results of both RAMs, however, the match with the probability map (presumed to be “reality”) is not good. In both RAMs sand and loamy sand soils are indicated as more vulnerable than clay soils, while in the probability map sand subsoils suffer less of subsoil compaction than clay soils. Of concern is that, according to the probability map, about 50% of the most productive and fertile soils of The Netherlands have overcompacted subsoils.

Abstract: Browsing and trampling by nonnative feral pigs (Sus scrofa) negatively impact native flora and fauna in forested ecosystems and cause soil compaction. However, their impact on runoff and erosion is largely unknown. This study addressed this knowledge gap by investigating effects of feral pigs on runoff volume and total suspended solids (TSS) in runoff from the upper forested area of a Hawaiian watershed. Correlations between TSS, runoff, and other environmental variables were also examined. Runoff was collected monthly after 11 individual storm events from June 2008 to April 2009 at seven sites in the Mānoa watershed on the island of O'ahu. Each site consisted of paired runoff plots (5.04 m2) with one plot located inside a fenced pig exclosure (exclosures 1 yr old at study initiation) and the other located in an adjacent area open to feral pigs. Forest composition and structure (stem density, stand basal area, and seedling/ sapling counts) were quantified at each site. Soil moisture, throughfall...

Abstract: In the East African highlands, crop yields tend to increase with proximity of the farm plots to homesteads. Farmers identified soil erosion as the most detrimental cause of low crop yield in the outfields followed by soil compaction due to livestock trampling. The main objective of this study was to determine whether zai pits (i.e. small water harvesting pits) developed for dryland regions of the Sahel could increase crop yield and water productivity of degraded outfields in high rainfall areas, where mean annual rainfall exceeds 1300 mm but soil water infiltration is reduced by slope, low soil organic matter and hardpans. The pits were enlarged to resist strong runoff flows. The research was conducted over three years from 2004 to 2006. Potatoes and beans were used as test crops. Overall, compared to control plots, the zai pits, in combination with nitrogen (N) inputs, increased potato yields from 500% to 2000% (p ≤ 0.001). The pits contributed more to increased crop yield than N inputs. Similarly, bean yields from the zai pits were up to 250% higher. Crop water productivity was 300–700% higher with zai pits than with control plots. The income of farmers who used zai pits was up to 20-fold higher than the labour costs required to prepare them. Contrary to conventional wisdom, this study reveals that the major constraint of the outfields is not nutrient deficiency per se rather low soil water holding capacity, which hinders crop growth and efficient utilization of available nutrients.

Abstract: Within the Speeding Up Sugar Yield (SUSY) project, soil management and soil characteristics were investigated as possible causes of yield differences in fields between 26 ‘type top’ and 26 ‘type average’ growers, ‘top’ and ‘average’ performance being based on past yield data. Growers were pairwise selected so that pairs were located in close proximity and on soils of the same texture. In the project years 2006 and 2007, the top growers had 20% (P <0.001) higher sugar yields compared to the average growers. Top growers made use of comparable equipment, but applied lower tyre inflation pressures and a lower number of field operations for seedbed preparation; their drilling dates were also earlier compared with average growers. This did not result in a significant difference in mean air-filled porosity at field capacity in the topsoil (AP) between grower types, but top growers sowed their beet earlier. The number of fields with a topsoil AP below 10% in the 10–15 cm layer was lower in the group of top growers (13 fields) than in the group of average growers (18 fields). Direct effects of soil management characteristics on AP could not be distinguished statistically without the factor grower type, but may have remained undetected because both management characteristics and AP appeared to be strongly related to topsoil clay content. Mean saturated hydraulic conductivity (Ks) in the most dense 5-cm thick subsoil layer (within 25–45 cm depth range) was significantly higher for fields of top growers than for average growers at 0.49 and 0.31 m day-1, respectively. Mean Ks was below a damage threshold level of 0.10 m day-1 on 34% of the average growers’ fields and on 27% of the top growers’ fields. Ks was zero (0.00) m day-1 on 9% of all fields. The relative importance of these findings is discussed in this paper. In a multiple regression analysis without the factor grower type, 15.3% of the variability of Ks was explained by a model with the terms of fine sand fraction (50–105 µm) in the subsoil and depth of primary tillage (Dpt; m). A statistical model with AP of the topsoil and Ks of the subsoil could explain 24.9% of the variation in sugar yield for all fields tested, being representative for Dutch sugar beet production, indicating that a good soil structure is needed to obtain high sugar yields. Highlights ? The fields of higher yielding top growers had higher Ks and thus less subsoil compaction compared to the average growers. ? Top growers made better use of the same equipment at seedbed preparation. ? AP depended strongly on topsoil clay content. ? Depth of primary tillage and the nature of the soil (sand content subsoil) explained the Ks by 15.3%. ? In dependency of subsoil fine sand content and sowing date, Ks and AP explained 24.9% of variance in sugar yield. Keywords: Grower performance; Competitiveness; Beta vulgaris L.; Soil compaction; Hydraulic conductivity; Air-filled porosity; Sowing date; Tyre inflation pressure; Sugar yield; Pairwise comparison; Soil management

Abstract: The objective of this work was to evaluate the effect of winter land use on the amount of residual straw, the physical soil properties and grain yields of maize, common bean and soybean summer crops cultivated in succession. The experiment was carried out in the North Plateau of Santa Catarina state, Brazil, from May 2006 to April 2010. Five strategies of land use in winter were evaluated: intercropping with black oat + ryegrass + vetch, without grazing and nitrogen (N) fertilization (intercropping cover); the same intercropping, with grazing and 100 kg ha -1 of N per year topdressing (pasture with N); the same intercropping, with grazing and without nitrogen fertilization (pasture without N); oilseed radish, without grazing and nitrogen fertilization (oilseed radish); and natural vegetation, without grazing and nitrogen fertilization (fallow). Intercropping cover produces a greater amount of biomass in the system and, consequently, a greater accumulation of total and particulate organic carbon on the surface soil layer. However, land use in winter does not significantly affect soil physical properties related to soil compaction, nor the grain yield of maize, soybean and common bean cultivated in succession.

Abstract: Impacts of organic matter removal and compaction on soil properties and productivity are reported from the first 10 years of the Long-Term Soil Productivity Study in Great Lakes aspen ecosystems. Organic matter removal treatments included main bole, total tree harvest, and total tree harvest with forest floor removal. Compaction treatments included minimal compaction, moderate, and heavy compaction. Treatments were replicated on a clay loam, silt loam, and loamy sand soils. Compaction treatments on all soils increased bulk density above preharvest levels. In most cases, bulk density at year 10 was still above preharvest levels. Total carbon, nitrogen, and cations showed little or no impact from treatment. Compaction and organic matter removal impacted aboveground productivity, however the responses were variable. Aboveground production declined on the loam soil with moderate and heavy compaction. Production increased with moderate compaction on the loamy sand and clay loam soils, but significantly decreased with heavy compaction on clay loam soil. Total tree harvest with forest floor removal reduced production on the loamy sand and loam soils, while it increased production on the clay loam soil. Results from this study suggest that heavy compaction and/or high organic matter removals are detrimental to sustaining forest productivity.

Abstract: Purpose Soil strength and thus stability concerning wind erosion are controlled by the soil water content. The concept of soil critical water content (Θcrit.) for deflation was extended to include matric potential (Ψcrit.) as well. The focus of this paper is to quantify the Θcrit. and Ψcrit. as the upper boundary for wind erosion or as the lower boundary for soil strength, to model the Ψcrit. at the immediate soil surface (0–0.2 cm) and to evaluate the effect of soil moisture upon erosion as a function of time and sampling height.

Abstract: Soil compaction is an important environmental problem and it causes physical degradation by adversely influencing hydraulic properties of soil and productivity parameters. It can affect root development and nutrient uptake. Objective of this study is to determine effects of soil compaction on root development and nutrient uptake of forage crops. Trial was carried out for 3.5 months in PVC cylindrical pots filled with clay loam soils with hairy vetch (Vicia villosa Roth.), common vetch (Vicia sativa L.), Italian ryegrass (Lolium italicum Lam.) and barley (Hordeum vulgare L.) plants. Statistical analyses showed that as the bulk density increased, root length and root surface area decrease (statistically significant in common vetch and nonsignificant in Italian ryegrass and barley). Increase in bulk density caused in all plants a significant decrease (p≤0.05) in dry weights of root and shoot. Plant generally had lower quantities of nitrogen (N), calcium (Ca), and magnesium (Mg) and higher quantities of phosphorus (P), iron (Fe), manganese (Mn), and zinc (Zn) as the bulk density increased.

Abstract: The determination of the compaction parameters such as optimum water content (wopt) and maximum dry unit weight (γdmax) requires great efforts by applying the compaction testing procedure which is also time consuming and needs significant amount of work. Therefore, it seems more reasonable to use the indirect methods for estimating the compaction parameters. In recent years, the artificial neural network (ANN) modelling has gained an increasing interest and is also acquiring more popularity in geotechnical engineering applications. This study deals with the estimation of the compaction parameters for fine-grained soils based on compaction energy using ANN with the feed-forward back-propagation algorithm. In this study, the data including the results of the consistency tests, standard and modified Proctor tests, are collected from the literature and used in the analyses. The optimum structure of a network is determined for each ANN models. The analyses showed that the ANN models give quite reliable estimations in comparison with regression methods, thus they can be used as a reliable tool for the prediction of wopt and γdmax. Copyright © 2010 John Wiley & Sons, Ltd.

Abstract: Tap-rooted rapeseed is generally considered sensitive to soil compaction. We examined 473 Finnish rapeseed fields sown in 2007 to 2009 to both spring turnip rape Brassica rapa L. (dominant crop) and oilseed rape Brassica napus L. Roots were rated late in the growing season according to penetration capacity. Roots in each field were rated from G1 (no problems with root penetration) to G5 (failure to penetrate deeper soil layers). There were significant effects of year, crop species, soil type, special soil properties and soil cultivation methods on frequency of G1 and G4 + 5 roots. Restricted root penetration was a common phenomenon. Typically, fields had 70% G4 + 5 roots and were cases for serious concern. Yield loss was linearly related to the incidence of G4 + 5 plants in 2007, but there was no relationship with the other years. Oilseed rape had a greater proportion of G4+5 roots than turnip rape and twice the proportion of G4 + 5 roots occurred in direct-drilled fields than in reduced or fully tilled fields. Rapeseed yield decline may at least partly be related to poor root penetration and it is a useful indicator crop to demonstrate the degree of soil compaction and should be cultivated in fields where sufficient root penetration is possible.

Abstract: Earthwork quality control/quality assurance specifications are currently being developed and implemented with continuous compaction control (CCC) and intelligent compaction (IC) rollers. This paper presents and explores two methods of using CCC/IC data based on a relative compaction approach. The first method examines the relative change in roller-measured mean compaction level between passes while the second method examines relative changes spatially. The relative compaction methods were implemented on a test site. The relative compaction methods were found to provide improvement over current methods due to their ability to quantitatively assess 100% of the compacted area while decreasing time and cost during the construction process.

Abstract: Most peanut (Arahcis hypogaea L.) production occurs under highly intensive conventional tillage systems. With recent volatility in input prices, reducing tillage trips is a viable way of reducing production costs. However, growers can experience yield loss when switching from conventional tillage to strip-tillage in peanut on certain soil types due to the lack of an elevated bed at harvest time. Studies were conducted to compare standard strip-till with strip-till on two-row raised beds as well as rip and beds prepared in the fall. Comparisons were made on a coarse textured soil at Tifton, GA and a fine textured soil at Plains, GA. The three bed types, with and without wheat cover, were evaluated over two years at both locations. No effects of cover or interactions with bed type were present. At Plains, the rip and bed and raised bed reduced digging losses by 62 and 47%, respectively. Soil compaction within the harvest depth was reduced by 3.3 and 4.7 times by the raised bed and rip and bed, resp...

Abstract: The operation of forest traffic is related to use of machines that pass through the same line repeatedly or randomly, which may cause soil compaction, changing the environment of root growth system development and reducing the productivity. Besides the number of passes, the wood load carried may also affect soil compaction, when the applied pressures by machines exceed soil load support capacity. The objectives of this study were: a) to propose a load support capacity model for a Oxisol (Red-Yellow Latosol, LVA) as a function of preconsolidation pressure and moisture content; b) to determine, through the model, the effect of traveling and load intensity of a forwarder on the soil structure. To obtain the load support capacity models, 20 undisturbed soil samples were collected in the depth of 0-3 and 10-13 cm, at a site where there was no traffic. Also 10 undisturbed soil samples were collected for each depth where the Forwarder passed though 2, 4 and 8 times, and where the Forwarder passed in the same line 4 times with 1/3 (3 m3), 2/3 (6 m3) e 3/3 (9 m3) of its load. The undisturbed soil samples were used in the uniaxial compression tests. The particle size distribution, organic matter content, particle density and soil density were also determined. The load support capacity model for the Oxisol is expressed by the equation sp = 10 (2,71 - 1,36 U). All the traffic intensities caused soil compaction in the two depths, where four passes caused highest soil compaction, and as the Forwarder load increased, the soil compaction also increased in the two depths.

Abstract: This study aimed to evaluate the effect of additional compaction on the physical-hydraulic attributes and wheat yield (Triticum spp) in an Oxisol under no-tillage. The cultivation was made in strips (10x50m) which were implanted in four treatments or states of compaction: SC - without additional compaction with a roller compactor 1P- one roller pass, 3P- tree rolear passes and 5P- five roler passes. To evaluate soil bulk density (Bd), macroporosity (Map), microporosity (Mip) and total porosity (Tp), undisturbed soil samples were collected from three layers: 0,0-0,1, 0,1-0, 2 and 0.2-0.3m, at five random locations in each treatment. Soil samples were also collected in the layer 0.0 to 0.3m to perform the Proctor test and determine the maximum soil bulk density (Bdmax). The water infiltration rate in the soil was evaluated by means of concentric rings. The relative soil bulk density (Bdrel) was calculated using the relationship between the Bd and Bdmax. To determine the wheat yield a useful area of 4.08m2 was delimited and harvested, with five replicates in each treatment. By increasing the number of roller compactor passes, there was a reduction in Map and increase in Bd. The wheat yield and the infiltration rate decreased, respectively, by 23% and 97% when comparing SC treatment on 5P. The optimal Bdrel wheat yield in this Oxisol was of 0.83.

Abstract: The intensity and extent of soil compaction caused by timber harvesting was examined in the jarrah (Eucalyptus marginata) forest of south-west Western Australia. The extent of soil compaction was determined by mapping soil disturbance categories. The intensity of compaction was determined from the bulk density of these disturbance categories. Bulk density of surface soil (0-100 mm) was measured across monitoring grids established for the Forestcheck project on eleven harvested sites and seven sites that had never been harvested. Surface soils on sites that had never been harvested had a mean fine earth bulk density of 0.71 g cm. Timber harvesting increased the bulk density of surface soils by a mean of 0.15 g cm. Compaction was greatest on log landings and primary and secondary extraction tracks where fine earth bulk density was increased by 0.27 g cm compared to never-harvested forest. Compaction on the general harvested area (0.13 g cm), which excludes the extraction tracks, was about half that of log landings and extraction tracks. The intensity of soil compaction was consistent with increases observed as a result of timber harvesting in a range of other forests. Although the intensity of harvesting activity and the volume of logs removed is typically greater in gap release than in shelterwood treatments, there was no significant difference in soil compaction between these treatments. Soil compaction did decline as the intensity of individual disturbance activities inside harvested areas declined. Given the potential and demonstrated effects of soil compaction and disturbance on jarrah forest ecosystems, and the potentially long time periods indicated for the amelioration of soil compaction in these forests, ongoing operational management and monitoring of this disturbance is required to limit long-term effects on the productive capacity of jarrah forest.

Abstract: Weed management is considered one of the activities that degrade the soil structure most in coffee crops, due to the soil compaction caused by weed control operations. The objective of this study was to determine the bearing capacity models for no weed control and to use this model to determine which weed management causes smaller or greater soil compaction. The study was conducted on a Red-Yellow Latosol (LVA), under coffee (variety Topazio MG 1190), on the Experimental Farm of EPAMIG in the community Farias, Lavras-MG (latitude 21°14'43" S, longitude 44°59'59" W). The following weed managements were assessed: a) in the traffic line of the inter-rows - disc harrow, post-emergence herbicide, pre-emergence herbicide, mower and brush and b) in the center of the inter-rows - peanut (Arachis pintoi), braquiaria (Brachiaria decumbens), hand weeding, sunhemp (Crotalaria juncea) and soybean (Glycine max L). The sampling consisted of two stages, one to determine the bearing capacity models for the treatment no weeding and another to assess the compaction caused by the other weed management. To determine the bearing capacity model for the treatment no weeding, 20 undisturbed soil samples from the layers 0-3, 10-13 and 25-28 cm were collected in the middle of the inter-rows, totaling 60 samples. These samples were subjected to the uniaxial compression test to obtain the preconsolidation pressure and the volumetric water content, which were used to determine the bearing capacity model. To determine the compaction caused by the other weed managements, based on mechanical control, 180 samples with undisturbed structure were collected in January 2010 from the traffic lines of the inter-rows, (5 weed management x 3 depths x 12 soil samples with undisturbed structure). For the weed managements using cover crops, in January 2010, 180 samples with undisturbed structure (5 weed management x 3 depths x 12 soil samples with undisturbed structure) were collected from the middle of the inter-rows These samples were submitted to the uniaxial compression test to determine preconsolidation pressure and the volumetric water content after applying the weed managements and were used in the criteria proposed by Dias Junior et al. (2005) to determine the compaction caused by these managements. By the bearing capacity models and the preconsolidation pressure determined after implementing the weed managements, the treatments disc harrow, mower and brush were detected for causing greatest soil compaction and braquiaria, sunhemp and soybean as causing least compaction in the three studied layers.

Abstract: Soil compaction prevents turfgrass roots from growing deep into the soil and may limit access to water and nutrients. The objective of this study was to characterize the ability of turfgrass roots to penetrate a compacted subsurface layer. Seven turfgrasses were grown in soil columns. Each column was divided into three sections with the top and bottom packed to a bulk density of 1.6 g cm−3, and the middle (treatment) layer packed to 1.6, 1.7, 1.8, 1.9, or 2.0 g cm−3. Subsurface compaction reduced root mass for two of the species, and inhibited deep root growth in all seven species, with the greatest reduction occurring between 1.7 and 1.8 g cm−3. There appears to be little difference between species in ability to penetrate compacted soils, suggesting that soil preparation and routine management practices, rather than grass selection, is the more viable way to handle soil compaction problems in turf.

Abstract: Soil compaction connected with tractor traffic leads to changes in roots morphology and decreased plant yields of both annual and perennial forage plants. The aim of this study was to quantify the effect of soil compaction on alfalfa herbage production and root growth. A pot experiment with different levels of soil compaction was conducted in 2007-09. Plant yield and root morphology such as root length density (RLD), mean root diameter (MD), specific root length (SRL), and root dry matter (RDM) were determined. Root dry matter distribution in uncompacted soil was uniform in the investigated soil layers. In compacted soil the main root matter was located in the upper soil layer. Generally, roots were also much longer in the upper soil layer (0-10 cm) than below 10 cm. The value of RLD decreased in treatments with a higher degree of compaction. It was observed that roots in more compacted soil were thinner than in uncompacted. Based on the results in herbage production, the reaction of plant yield to soil compaction can be described as positive. In the first year of the experiment (2007), soil compaction caused a significant decrease in plant yield. However, in 2008 and 2009 the opposite effect was noticed when yields were significantly higher in strongly compacted soil than in less compacted.

Abstract: Soil compaction can be minimized either mechanically or biologically, using plant species with vigorous root systems An experiment was carried out with soybean (Glycine max) in rotation with triticale (X Triticosecale) and sunflower (Helianthus annuus) in fall-winter associated with pearl millet (Pennisetum glaucum), grain sorghum (Sorghum bicolor) or sunn hemp (Crotalaria juncea) in spring Crop rotation under no-till was compared with mechanical chiseling The experiment was carried out in Botucatu, Sao Paulo State, Brazil Soil quality was estimated using the S index and soil water retention curves (in the layers of 0-005, 0075-0125, 015-020, 0275-0325, and 0475-0525 m deep) Crop rotation and chiseling improved soil quality, increasing the S index to over 0035 to a depth of 20 cm in the soil profile The improved soil quality, as shown by the S index, makes the use of mechanical chiseling unnecessary, since after 3 years the soil physical quality under no-tilled crop rotation and chiseling was similar

Abstract: Soil compaction was measured at four sites within two abandoned mining camps in the western Great Basin Desert, Nevada. Bulk density and macroporosity values were generated from soil samples collected in areas of different land use intensities in camps that had been abandoned for approximately 70 years. Results show that significant differences remain in bulk density values between abandoned roads and undisturbed areas in both towns, and that the areas around foundation peripheries are still significantly more compacted in one town. There were no significant differences between land use groups as measured by macroporosity. Estimated soil recovery, based on a linear model using bulk density values, suggests that approximately 100 to 130 years are necessary for complete loosening to occur for abandoned roads, and that 100 or fewer years are necessary for complete amelioration of the foundation periphery areas. The wetter townsite, with more freeze-thaw days, finer-grained soils, and greater plant cover, had shorter recovery estimates. These findings suggest that the results of human-use impacts in arid areas may still be apparent long after disturbances cease.

Abstract: The economic and environmental repercussion of the agricultural soils compaction has propitiated the development of new means and methods to avoid it, for wh...

Abstract: A method is described here for the monitoring of two layers of moist sandy-loam soil under compaction, where a flatbed scanner is used to capture large images of the deforming material. Particle image velocimetry (PIV) is used to track the movements of groups of particles within the soil. Due to their insufficient surface texture, PIV cannot be used on clayey soils. Therefore, to allow the analysis to take place, a novel use of a transparent clay is made whereby an artificial soil comprising transparent clay, sand and gravel is created to approximate the moist sandy loam soil. The design of a suitable compaction chamber and tests to determine optimal PIV parameters are discussed. The suitability and applicability of the use of a flatbed scanner are discussed and results are shown to confirm the success of the scanning method.