Abstract: Grazing effects on soil properties under different soil and environmental conditions across the globe are often controversial. Therefore, it is essential to evaluate the overall magnitude and direction of the grazing effects on soils. This global meta-analysis was conducted using the mixed model method to address the overall effects of grazing intensities (heavy, moderate, and light) on 15 soil properties based on 287 papers published globally from 2007 to 2019. Our findings showed that heavy grazing significantly increased the soil BD (11.3% relative un-grazing) and PR (52.5%) and reduced SOC (-10.8%), WC (-10.8%), NO3- (-23.5%), and MBC (-27.9%) at 0–10 cm depth, and reduced SOC (-22.5%) and TN (-19.9%) at 10–30 cm depth. Moderate grazing significantly increased the BD (7.5%), PR (46.0%), and P (18.9%) (0–10 cm), and increased pH (4.1%) and decreased SOC (-16.4%), TN (-10.6%), and P (-23.9%) (10–30 cm). Light grazing significantly increased the SOC (10.8%) and NH4+ (28.7%) (0–10 cm). Heavy grazing showed much higher mean probability (0.70) leading to overgrazing than the moderate (0.14) and light (0.10) grazing. These findings indicate that, globally, compared to un-grazing, heavy grazing significantly increased soil compaction and reduced SOC, NO3-, and soil moisture. Moderate grazing significantly increased soil compaction and alkalinity and reduced SOC and TN. Light grazing significantly increased SOC and NH4+. Cattle grazing impacts on soil compaction, SOC, TN, and available K were higher than sheep grazing, but lower for PR. Climate significantly impacted grazing effects on SOM, TN, available P, NH4+, EC, CEC, and PR. Heavy grazing can be more detrimental to soil quality based on BD, SOC, TN, C: N, WC, and K than moderate and light grazing. However, global grazing intensities did not significantly impact most of the 15 soil properties, and the grazing effects on them had insignificant changes over the years.

Abstract: Belowground roles of agroforestry in climate change mitigation (C storage) and adaptation (reduced vulnerability to drought) are less obvious than easy-to-measure aspects aboveground. Documentation on these roles is lacking. We quantified the organic C concentration (Corg) and soil physical properties in a mountainous landscape in Sulawesi (Indonesia) for five land cover types: secondary forest (SF), multistrata cocoa–based agroforestry (CAF) aged 4–5 years (CAF4), 10–12 years (CAF10), 17–34 years (CAF17), and multistrata (mixed fruit and timber) agroforest (MAF45) aged 45–68 years. With four replicate plots per cover type, we measured five pools of C-stock according to IPCC guidelines, soil bulk density (BD), macro porosity (MP), hydraulic conductivity (Ks), and available water capacity of the soil (AWC). The highest C-stock, in SF, was around 320 Mg ha−1, the lowest, 74 Mg ha−1, was in CAF4, with the older agroforestry systems being intermediate with 120 to 150 Mg ha−1. Soil compaction after forest conversion led to increased BD and reduced MP, Ks, and AWC. Older agroforestry partly recovered buffering: AWC per m of rooted soil profile increased by 5.7 mm per unit (g kg−1) increase of Corg. The restored AWC can support about a week’s worth of evapotranspiration without rain, assisting in climate change adaptation.

Abstract: This experimental laboratory study examines the potential use of tire-derived aggregate (TDA) products as an additive to alleviate the inferior geotechnical properties of a subgrade deposit of clay soil with high expansivity. A total of ten mix designs—the unamended soil and nine soil–TDA blends prepared at 5%, 10% and 20% TDA contents (by dry mass) using three different TDA gradations/sizes—were examined. The experiments included standard Proctor compaction, oedometer swell and unconfined compression tests. The TDA materials’ lower specific gravity, hydrophobic character and higher energy absorption capacity compared with the soil solids led to notable reductions in the soil compaction characteristics. The amendment of the soil with TDA resulted in notable decreases in the rate and magnitude of swelling—the observed reductions were in favor of higher TDA contents, with larger TDA particle size being a secondary factor. Further, for any given TDA size, the variations of strength and toughness with respect to TDA content exhibited rise–fall relationships, peaking at 5% TDA and then decreasing for higher TDA contents. The stiffness and ductility parameters, however, were found to monotonically decrease and increase with the TDA content, respectively. Finally, TDA contents of up to 10%, with gradations equivalent to those of medium and coarse sands, were found to reduce the soil’s swelling potential from high to moderate expansivity, while simultaneously improving its strength-related features, and thus can be deemed as optimum mix design choices from a geotechnical perspective.

Abstract: Optimal resource planning is essential in developing countries, particularly in the Middle East, where scarcity of resources represents a major challenge for development. To eliminate inappropriate human influence on natural resources and develop a strategy for appropriate land use, land evaluation (LE) assessments are crucial to be properly carried out. In this context, land suitability (LS) assessment was performed in Port Said Governorate. LE and LS were carried out for several field crops, vegetable crops, forage crops, and fruit trees. LS was matched based on the requirements of the selected crops, then it was associated with physiographic map units using a GIS platform. Different sources of remote sensing-derived maps were integrated and homogenized to increase the accuracy of physiographic. Moreover, land quality and soil characteristics mapping were conducted in Arc GIS spatial model to generate LS using geostatistical methods. The results revealed that structure of LS classification was four classes only, moderately suitable S2 = 36%, marginally suitable S3 = 30%, currently not suitable N1 = 23%, and permanently not suitable for crops N2 = 11% of total area of land), respectively, of land. The actual LS produced in association with physiographic units. The potential crops suitability was produced considering the significant fluctuation in land use in the area. Fluctuation changes in land use; fish farms led to increase organic matter (OM) to 2.3 from 0.4% in some soil profiles due to the fish farms practices in the area, and reduce soil electrical conductivity by 50% due to leaching effect. Severe limitations of crop suitability are due to defects associated with organic OM, soil compaction, salinization, alkalinization and carbonates. This work helps to achieve optimum use of available land resources to help in soil improvement and prevent land degradation. Comprehensive LS assessment is required to grow appropriate crops on marginal lands. Hence, there is an urgent need for developing a crop suitability framework for optimum use of land in the area. This approach provides an integrated approach to identify suitable crops for areas with physical constraints.

Abstract: Reducing potential soil damage due to the passing of forest machinery is a key issue in sustainable forest management. Limiting soil compaction has a significant positive impact on forest soil. With this in mind, the aim of this work was the application of precision forestry tools, namely the Global Navigation Satellite System (GNSS) and Geographic Information System (GIS), to improve forwarding operations in hilly areas, thereby reducing the soil surface impacted. Three different forest study areas located on the slopes of Mount Amiata (Tuscany, Italy) were analyzed. Extraction operations were carried out using a John Deere 1410D forwarder. The study was conducted in chestnut (Castanea sativa Mill.) coppice, and two coniferous stands: black pine (Pinus nigra Arn.) and Monterey pine (Pinus radiata D. Don). The first stage of this work consisted of field surveys collecting data concerning new strip roads prepared by the forwarder operator to extract all the wood material from the forest areas. These new strip roads were detected using a GNSS system: specifically, a Trimble Juno Sb handheld data collector. The accumulated field data were recorded in GIS Software Quantum GIS 2.18, allowing the creation of strip road shapefiles followed by a calculation of the soil surface impacted during the extraction operation. In the second phase, various GIS tools were used to define a preliminary strip road network, developed to minimize impact on the surface, and, therefore, environmental disturbance. The results obtained showed the efficiency of precision forestry tools to improve forwarding operations. This electronic component, integrated with the on-board GNSS and GIS systems of the forwarder, could assure that the machine only followed the previously-planned strip roads, leading to a considerable reduction of the soil compaction and topsoil disturbances. The use of such tool can also minimize the risks of accidents in hilly areas operations, thus allowing more sustainable forest operations under all the three pillars of sustainability (economy, environment and society).

Abstract: Avoiding soil compaction is one of the objectives to ensure sustainable agriculture. Subsoil compaction in particular can be irreversible. Frequent passages by (increasingly heavy) agricultural machinery are one trigger for compaction. The aim of this work is to map and analyze the extent of traffic intensity over four years. The analysis is made for complete seasons and individual operations. The traffic intensity is distinguished into areas with more than five wheel passes, more than 5 Mg and 3 Mg wheel load. From 2014 to 2018, 63 work processes on a field were recorded and the wheel load and wheel passes were modeled spatially with FiTraM. Between 82% (winter wheat) and 100% (sugar beet) of the total infield area is trafficked during a season. The sugar beet season has the highest intensities. High intensities of more than five wheel passes and more than 5 Mg wheel load occur mainly during harvests in the headland. At wheel load ≥3 Mg, soil tillage also stresses the headland. In summary, no work process stays below one of the upper thresholds set. Based on the results, the importance of a soil-conserving management becomes obvious in order to secure the soil for agriculture in a sustainable way.

Abstract: Over the last decade, monoculture plantations have rapidly developed in Jambi Province on Sumatra, Indonesia. Meanwhile, there has been intensification of discharge fluctuation in the study area. ...

Abstract: Ground-based skidding operations can lead to soil compaction and displacement, which could cause negative effects on forest soil. Hence, some efforts such as forestry best management practices (BMPs) must be implemented in the prone area to mitigate these possible impacts. Several materials and treatments have been adopted to suppress these adverse effects by increasing the ground cover. However, the effects of mulch treatments on runoff and sediment yield are inconclusive with a diverse range of effectiveness. For these reasons, in this research mulch treatments were tested as to determine how the application of organic mulch amendments such as straw and leaf litter and contour-felled logs would alleviate the runoff and sediment yield on machine operating trails and ensure successful hillslope stabilization. The aims of the study were to analyse and compare the effectiveness of leaf litter (LM) and straw mulch (SM) rate and different distances of contour-felled logs (CFL) to mitigate the runoff and sediment yield, and examine the impact of rainfall intensity on effectiveness of litter mulch, straw mulch, and contour-felled logs. Totally, 30 bounded runoff plots in the machine operating trails and four treatments including litter mulch (LMR1: 0.62, LMR2: 1.24, and LMR3: 1.86 kg m), straw mulch (SMR1: 0.45, SMR2: 0.92, and SMR3: 1.34 kg m), contour-felled logs (CFL10: 10, CFL20: 20, and CFL30: 30 m), and untreated area were established in triplicate with 4 m width and 100 m length. During the study period, the runoff and sediment yield in the untreated trails (U) were 2.36 mm and 11.84 g m. Straw (from 41.5 to 60.6%) and litter mulch (from 38.1 to 55.1%), and contour-felled logs treatments (from 70.8 to 88.1%) significantly decreased the runoff, compared to U treatment. Results show that mulch treatments with three different levels of Litter Mulch Rate, LMR1, LMR2, and LMR3 decreased mean sediment by 46.6, 64.0 and 71.8%, in the treatments with three different levels of Straw Mulch Rate, SMR1, SMR2, and SMR3 decreased mean sediment by 42.9, 62.1, and 69.9%, and in the treatments with three different distances of Contour-Felled Logs, CFL10, CFL20, and CFL30 decreased mean sediment by 90.6, 94.7 and 88.3% comparing to U, respectively. The relationships of the runoff and sediment responses to increasing mulching rate of litter and straw followed as negative logarithmic curves, but the decreasing-increasing trends were observed in runoff and sediment yield as the distance between contour-felled logs increased from 10 to 30 m. Polynomial regression equations were developed for predicting the runoff and sediment yield as a function of the application rate of litter and straw mulch and the distance between contour-felled logs, and rainfall intensity. We concluded that contour-felled logs treatment was more effective than both litter and straw mulch to mitigate the runoff, runoff coefficient, and sediment yield on machine operating trails. As a management measure, it could be possible to propose that the contour-felled logs with a distance of 20 m be prescribed to protect the machine operating trails from the negative effects of surface waterflow.

Abstract: The paper deals with the damage of the remaining stand and soil caused by harvesting using three ground-based forest operations methods (harvester-forwarder/cable skidder/animal-tractor). It compares the impact of the most common harvesting technologies applied in Slovakia and in Central Europe and thus contributes with valuable information to the knowledge on the suitability of their application in forests stands dominated by broadleaved tree species. Harvesting was performed in five forest stands located at the University Forest Enterprise of Technical University in Zvolen in central Slovakia from August to October 2019. Damage to remaining trees was assessed from the point of its size, type, and position of damage along stem. We expected lower damage of remaining trees in stands where harvesters were used because of the applied cut-to-length short wood system and fully mechanized harvesting system. In addition, we examined soil bulk density and soil moisture content in ruts, space between ruts, and in undisturbed stand to reveal the impact of harvesting machinery on soil. We expected greater soil bulk densities and lower soil moisture content in these stands due to the greatest weight of harvesters and in ruts created by machinery compared with undisturbed stand soil. The highest percentage of damaged remaining trees equal to 20.47% and 23.36% was recorded for harvester forest operations, followed by skidder (19.44%) and animal forest operations with 19.86% and 14.47%. Factorial ANOVA confirmed significant higher soil compaction in stands where harvesters were used (higer bulk density) than in stands where skidding was performed with the skidder and animal power. Higher soil moisture content was recorded in ruts created by harvesters and the skidder. The lowest soil moisture content was in undisturbed stands irrespective of the applied forest operation method.

Abstract: A new intelligent compaction method for vibratory soil compaction rollers that automatically and continuously adjusts the vibration frequency to obtain resonance in the coupled roller–soil system w...

Abstract: Although compacted soil can be recovered through root development of planted seedlings, the relationship between root morphologies and soil physical properties remain unclear. We investigated the impacts of soil compaction on planted hybrid larch F1 (Larix gmelinii var. japonica×L. kaempferi, hereafter F1) seedlings with/without N loading. We assumed that N loading might increase the fine root proportion of F1 seedlings under soil compaction, resulting in less effects of root development on soil recovery. We established experimental site with different levels of soil compaction and N loading, where two-year-old F1 seedlings were planted. We used a hardness change index (HCI) to quantify a degree of soil hardness change at each depth. We evaluated root morphological responses to soil compaction and N loading, focusing on ectomycorrhizal symbiosis. High soil hardness reduced the total dry mass of F1 seedlings by more than 30%. Significant positive correlations were found between HCI and root proportion, which indicated that F1 seedling could enhance soil recovery via root development. The reduction of fine root density and its proportion due to soil compaction was observed, while these responses were contrasting under N loading. Nevertheless, the relationships between HCI and root proportion were not changed by N loading. The relative abundance of the larch-specific ectomycorrhizal fungi under soil compaction was increased by N loading. We concluded that the root development of F1 seedling accelerates soil recovery, where N loading could induce root morphological changes under soil compaction, resulting in the persistent relationship between root development and soil recovery.

Abstract: Chestnut forests represent an important environmental and landscape element in Europe, especially in the hill regions of southern Europe. In Italy, the total surface amount of chestnut forests is slightly expanded with 788,408 hectares, but orchards show a dramatic reduction (147,586 hectares or 20% of the total) and timber-producing stands a comparable expansion (605,888 hectares or 80%). The coppice management actually applied is considered one of the oldest forms of sustainable forest management. Over the years, coppice highlighted its versatility, resilience and multifunctionality. In this management system, in consideration of the “frequent” cutting cycles, special attention must be paid to forestry operations, because tree damage and soil compaction can trigger fungal disease and soil erosion. Frequent and repeated machine traffic increases the risk for soil degradation derived from compaction, topsoil removal and general disturbance. This study covered different forest areas and mechanization levels, in order to evaluate if the extent, type and severity of soil disturbance changed with site characteristics and logging technique. Furthermore, the study sought to obtain a better knowledge about the recovery time required for restoring the original soil properties after a disturbance has occurred. The findings showed that physical, chemical, and biological soil features were only partially disturbed by the coppicing and again that a high level of specialized mechanization does not generate heavier soil impact compared with the smaller and lighter machines deployed under the traditional and intermediate mechanization scenarios. Soil recovery in the impacted areas is already measurable one year after harvest and may be complete within the eight year—that is halfway through the standard rotation applied in the region to chestnut coppice.

Abstract: Soil compaction has become a global concern that reduces soil quality and may jeopardize agricultural sustainability. The objective of this study is to evaluate if the freezing–thawing process can alleviate the negative effects of soil compaction during overwinter time in Northeast China. The field experiment was a split plot design including two surface treatments (bare and mulch) and three compaction levels (low, moderate, and high compactions with initial bulk densities of 1.2, 1.4 and 1.6 g cm−3). Results showed that compared with initial values in the fall, freezing–thawing events increased soil porosity (by 4.28% to 25.68%) and the ratio of large-size pores (by 44.5% to 387.6%) after thawing in the spring. The greatest changes were observed in the high compaction treatment, and mulch-enhanced soil structural transformation. Additionally, the ratio of large-size aggregates (>1 mm) was increased and the fraction of small-size aggregates (<1 mm) was decreased. These changes in soil structural characteristics were attributed mainly to the modification of ice-filled pores space during the overwinter period. We concluded that the freezing–thawing process was an effective natural force for ameliorating soil compaction in Northeast China.

Abstract: Digging mammals are often considered ecosystem engineers, as they affect important properties of soils and in turn nutrient exchange, vegetation dynamics and habitat quality. Returning such species, and their functions, to areas from where they have been extirpated could help restore degraded landscapes and is increasingly being trialled as a conservation tool. Studies examining the effects of digging mammals have largely been from arid and semi‐arid environments, with little known about their impacts and importance in mesic systems. To address this knowledge gap, we investigated the ecological role of a recently introduced population of eastern barred bandicoots (Perameles gunnii) on Churchill Island, Victoria, south‐eastern Australia, from which all digging mammals have been lost. We quantified the annual rate of soil turnover by estimating the number of foraging pits bandicoots created in 100‐m² plots over a 24‐h period. Foraging pit counts could not be completed in each season, and the overall turnover estimate assumes that autumn/winter months represent turnover rates for the entire year; however, this is likely to fluctuate between seasons. Ten fresh and ten old pits were compared to paired undug control sites to quantify the effect soil disturbance had on soil hydrophobicity, moisture content and soil strength. Plots contained between zero and 64 new foraging pits each day. We estimated that an individual eastern barred bandicoot digs ~487 (95% CI = 416–526) small foraging pits per night, displacing ~13.15 kg (95% CI = 11.2–14.2 kg) of soil, equating to ~400 kg (95% CI = 341–431 kg) of soil in a winter month. Foraging pits were associated with decreased soil compaction and increased soil moisture along the foraging pit profile. Eastern barred bandicoots likely play an important role in ecosystems through their effects on soil, which adds to an increasing body of knowledge suggesting restoration of ecosystems, via the return of ecosystem engineers and their functions, holds much promise for conserving biodiversity and ecological function.

Abstract: Understanding the response of plant community to degradation is fundamentally important for grassland conservation and management. The objective of this study is to examine the changes in soil properties and plant characteristics along a degradation gradient in alpine steppe, and explore the potential mechanisms that biotic and abiotic controls regulate plant community variations. We chose seven sequent degraded degrees, and conducted a field survey as well as soil and plant samplings in an alpine steppe in Northern Tibet. The results showed that soil water content (SWC), soil compaction (SCOM), soil total carbon (STC), and total nitrogen (STN) dramatically decreased along the degradation gradient. The species richness, overall aboveground biomass (AGB), and AGB of graminoids were apparently reduced with increasing degraded degrees, while AGB of forbs slightly increased. The increasing degradation levels induced a significant increase in the trade-off value of AGB of forbs, which was negatively associated with SWC, SCOM, STC, STN, and soil available nitrogen. The mean root length of forbs was significantly longer than that of graminoids (P<0.05). Moreover, the mean root diameter of the top 1/3 part of forbs was remarkably thicker than that of graminoids (P<0.05). These findings indicate that the degradation-induced cohesionless soils with insufficient water and nutrients together with the divergent root morphological traits of graminoids and forbs determine the plant community structure shift with grassland degradation. This study can improve the understanding of community succession of grassland degradation, and provide guidance for the management of degraded alpine steppe on the Tibetan Plateau.

Abstract: The impact of forest skidding machine tires on the soil differs depending on topography, soil properties, and type of the wheel system. The development of a mathematical model describing the entire dynamic process is a challenging but relevant task to assess the level of impact. The work aims mathematical modeling of the impact caused by the skidding system on the forest soil employing Kelvin-Voigt theory with additional elastic element and Laplace transform equations. A dynamic model represents the "tractor–timber bundle– soil" system. According to the results of mathematical modeling, it was found that studying the vertical vibrations and vibrations of sprung mass in longitudinal and transverse planes is sufficient for examining dynamic soil compaction. Developed methods of statistical dynamics with the presentation of the track surface microroughness and the theory of linear elastic and viscous soil deformation showed that each pass of the skidding system is ac-companied by additional dynamic soil compaction. Its maximum value depends on the properties of the soil and skidding system, as well as on the presence of resonant zones in the frequency spectrum. The results of these studies provide an opportunity to predict the exposure level of skidders and establish new solutions to minimize negative consequences for the environment and productivity of the forest industry.

Abstract: The “one-wheeled tramline” for multiple machinery widths (OWTL) method, which implies confining compaction to only one common permanent traffic lane (PTL) without changing wheel tracks of the machinery, has been proposed as first step to adopt the Controlled Traffic Farming system. The objective of this study was to evaluate how far the stress distribution, caused by repeated wheeling, affects maize and sunflower response in Argiudolls. The OWTL method was applied in two experimental sites, one cropped with maize (Aurelia site) and the other one with sunflower (Videla site). At each site, 9 plots were defined and one common PTL was established within each plot. Three compaction treatments were assigned to plots in a randomized complete block design with 3 replicates. The 3 compaction treatments were: T0: control, PTL with initial soil compaction defined for one pass of the planter equipment; T1: PTL compacted until the soil reached 2 MPa; T2: PTL compacted until the soil reached 4 MPa. Thereafter, the machinery traffic was restricted to the PTL. Fixed sampling positions were established in the PTL (from the centre to the outer edge) and in the permanent crop bed (PCB). After 18 months from the experiment begining, relative soil compaction (RSC) at the depth interval 0-100 and 100-200 mm, maize and sunflower yield, and sunflower root biomass (RB) were measured. Critical bulk density was 1.58 ± 0.03 Mg m-3 and 1.62 ± 0.05 at Aurelia and Videla sites. Significant differences of RSC between sampling positions were observed at both sites, whereas significant differences between compaction treatments were observed at Videla site. The higher RSC values were observed at the depth interval 100-200 mm in the PTL. The lower yields were observed in the centre of the PTL in T2. Contrasting the yield of maize and sunflower obtained in the PTL of T0 vs the average of T1 and T2, differences of 2751 and 848 kg ha-1 were observed. No yield differences were found for the same contrast in the PCB. Sunflower RB was reduced by 56% in the PTL, without differences between compaction treatments. The higher RB was found at the depth interval 0-100 mm (86% and 79% in the PTL and PCB, respectively). These results showed that the horizontal transmission of soil compaction caused by the OWTL depends on the RSC reached in the PTL. Crops yield and root growth were differently affected by the compaction treatments and the effect varied between sampling positions.

Abstract: Soil compaction is an important operation during the construction of road embankments, railway subgrade, earth dams and compacted clay liners for waste disposal. Soil compaction is usually controlled based on the ratio of the dry density of the soil to the soil water content. However, this relationship presents problems in both the laboratory and in the field when using excess compaction energy levels in cohesive soils with a high natural water content, including differences in the compaction energy levels and a reduction in strength as a result of over-compaction. The compaction curve, which considered the compaction energy levels, is usually unknown in the field and the main factors influencing the stiffness and strength of compacted soils are the dry density and the degree of saturation. We show here compaction results for soils in terms of the dry density and degree of saturation and introduce the concept of an optimum compaction line.

Abstract: The present paper addresses the problem of the dynamic response of a vibrating equipment for soil compaction. In essence, dynamic response vibrations are analysed by applying an inertial-type perturbing force. This is generated by rotating an eccentric mass with variable angular velocity, in order to reach the regime necessary to ensure the degree of compaction. The original character of the research is that during the compaction process, the soil layers with certain compositions of clay, sand, water and stabilizing substances change their rigidity and/or amortization. In this case, two situations were analysed, both experimentally and with numerical modelling, with special results and practical engineering conclusions, favourable to the evaluation of the interaction between vibrator roller–compacted ground. We mention that the families of amplitude–pulse and transmitted force–pulse response curves are presented, from which the dynamic effect in the compaction process results after each passage on the same layer of soil, until the necessary compaction state is reached.