Effects Of Soil Compaction Research Articles

Treading compaction during winter grazing can increase subsequent nitrate leaching by enhancing drainage

Nitrate leaching from agricultural production systems threatens groundwater and surface water quality. Grazing of forage crops can result in high inputs of urinary-N and soil compaction from livestock treading. However, the effects of soil compaction from winter grazing on nitrate leaching are poorly understood. The objective of this study was to test the hypothesis that the effects of soil compaction on nitrate leaching after winter grazing depend on rainfall (amount and temporal pattern) and evaporation-regulated soil water content. HYDRUS-1D was used to simulate post-winter grazing drainage and nitrate leaching with five degrees of soil compaction and four factors (i.e. forage crop establishment method, fallow period, climate, and urine addition). Empirical data were obtained from a previous experiment conducted on a moderately well-drained soil (Templeton silt loam, Udic Haplustept) in Canterbury, New Zealand. The results suggested that soil compaction can increase nitrate leaching, and this was more likely to occur in cultivated soils, following high input of urea N, during longer fallow periods and where rainfall is higher during the fallow periods (winter/spring). The increase in nitrate leaching from compaction was mainly attributed to greater drainage as a result of reduced evaporation and a lower capacity to retain water before drainage was triggered. A conceptual model was developed to explain the effect of compaction on drainage during two different phases of soil evaporation that depend on soil water content. This study highlighted the importance of soil water content to determining drainage and nitrate leaching. Therefore, management practices that help to promote soil drying by increasing evaporation (e.g. use no-tillage to establish forage crops to reduce compaction, shallow tillage after winter grazing) and transpiration (e.g. sowing a catch crop earlier) are essential to reducing the risk of drainage and nitrate leaching after winter grazing.

Short-term effects of compaction on soil mechanical properties and pore functions of an Andisol

Several studies on soil physical quality have related soil structural properties to bulk density, proposing values for critical limits in relation to the soil compaction status. However, these values are not applicable to Andosols due to their very low bulk density (< 0.9 Mg m−3). This work aimed to evaluate the short-term effects of soil compaction on the soil physical quality of an Andosol. The experiment was established in May 2019. Soil cores were collected from the soil surface and field measurements (penetration resistance, volumetric water content and air conductivity) were conducted to monitor changes in the soil physical quality after compaction events. The soil was compacted using rollers (weighing between 1.20 and 1.37 Mg) to reach three bulk densities (T0: 0.65, T1: 0.75 and T2: 0.85 Mg m−3) by controlling the number of roller passes. Soil compaction induced an increase in the soil bulk density that resulted in an increase in the mechanical strength (e.g. maps of penetration resistance revealed values from (T0) 500 kPa to (T2) 1500 kPa) and caused a decrease in the volume of macropores (e.g. air capacity in T0 and T2 was 22% and 11%, respectively) responsible for water infiltration and flow. The latter provoked an increase in the volumetric water content in the upper 10 cm of the soil, which decreased the field air conductivity due to the reduced pore space and its continuity. Bulk density also increased due to wetting and drying cycles, showing the effect of the natural rearrangement of soil particles, which was more intense in the soil with the lowest bulk density. When the bulk density of the tilled soil increased to values over 0.80 Mg m−3, soil pore functions related to soil aeration reached critical values (air capacity < 10% and air permeability < 1 µm2) concerning soil compaction, while the soil precompression stress (around 60 kPa) and plant available water (> 20%) remained within an optimal range.

Автомашины дугуйн мөрөөр үүсэх хөрсний эвдрэл, доройтлын судалгааны үр дүн (Шороон замын жишээн дээр)

According to the 2010 Desertification Map, 77.8 percent of Mongolia's territory is affected by desertification and land degradation, of which 35.3 percent are weak, 25.9 percent are moderate, 6.7 percent are strong, and 9.9 percent are very strong. (ADM, 2013). The effect of soil compaction is more pronounced in agriculture, especially in agricultural areas (Barnes, 1971). Soil compaction is a common or multifaceted process caused by human feet, cattle hooves, and car tire pressure (Lull, 1959). Most researchers have suggested that soil compaction is also caused by unpaved roads (Webb &amp; Wilshire, 1978). This soil compaction, caused by unpaved roads, is a key condition for rapid soil erosion (Snyder, 1976); (Iverson, 1980). According to a 2015 study by the Institute of Geography and Geoecology, a total of 3 million hectares have been destroyed by vehicle tires. The purpose of this article is to show the impact of unpaved roads on soil erosion and degradation in different natural areas of Mongolia. Unpaved road vehicles put a lot of pressure on the soil and leaves tires on the road, which has a very negative effect on soil loss, compaction and further water-physical properties of the soil. As of 1997, 8000-12,000 km2 of vehicle trails have been affected by desertification in Mongolia, which is a major factor in field degradation in some areas (MOE, 1997B). Therefore, the intensive use of unpaved roads has become an ecological (soil) imbalance. In this study, we collected soil bulk density samples in 3 times each from soil cover in 3 different natural zones at depths of 0-5 cm, 5-10 cm, and 10-15 cm, and measured the cross-section of unpaved roads, calculated the changes in their water-physical properties by laboratory methods and the amount of soil lost. As a result of the study, fine dust and loam from the unpaved road spread over a maximum of 30 km from the study area, covering an area of ​​100 km2, and the amount of soil lost per hectare in the forest-steppe zone was 196.97 tons. This is due to the fact that the soil cover is more compacted due to unpaved roads. The use of unpaved roads has a major negative impact on soil degradation in our country.

Mixed Effects of Soil Compaction on the Nitrogen Cycle Under Pea and Wheat.

Soil compaction caused by highly mechanized agriculture can constrain soil microbial diversity and functioning. Physical pressure on the soil decreases macropores and thereby limits oxygen diffusion. The associated shift from aerobic to anaerobic conditions can reduce nitrification and promote denitrification processes, leading to nitrogen (N) losses and N depletion that affect plant productivity. High soil moisture content during trafficking can exacerbate the negative effects of soil compaction. However, the extent to which soil moisture amplifies the effects of compaction on the soil microbiome and its control over N cycling is not well understood. Using a controlled greenhouse experiment with two different crops (pea and wheat), we compared the effects of compaction at three different soil moisture levels on soil physicochemical properties, microbial diversity, and the abundance of specific N species and quantification of associated microbial functional groups in the N cycle. Soil compaction increased bulk density from 15% (light compaction) to 25% (severe compaction). Compaction delayed germination in both crops and reduced yield by up to 60% for pea and 40% for wheat. Compaction further induced crop-specific shifts in microbial community structures. After compaction, the relative abundance of denitrifiers increased along with increased nitrate (NO3–) consumption and elevated nitrous oxide (N2O) concentrations in the soil pores. Conversely, the relative abundance of nitrifiers remained stable under compaction, but potentially decelerated nitrification rates, resulting in ammonium (NH4+) accumulation in the soil. This study showed that soil compaction effects are proportional to the initial soil moisture content, which could serve as a good indicator of compaction severity on agricultural fields. However, the impact of soil compaction on crop performance and on microbial communities and functions associated with the N cycle were not necessarily aligned. These findings demonstrate that not only the soil physical properties but also various biological indicators need to be considered in order to provide more precise recommendations for developing sustainable farming systems.

Effects of wildfire and soil compaction on recovery of narrow linear disturbances in upland mesic boreal forests

Energy exploration has led to fragmentation of habitats worldwide. In boreal forests of Alberta, Canada narrow clear-cut linear disturbances (3–14 m wide) called seismic lines are often the largest local source of forest fragmentation. Many lines have failed to recover decades after their creation leading to changes in forest dynamics and biodiversity. In some cases, these linear features function as habitat and/or corridors for species, while being detrimental in other species, most notably the threatened woodland caribou (Rangifer tarandus caribou). Recently, industry and government have focused on reforestation of these lines using silvicultural treatments and tree planting. However, these applications are expensive (> $12,500/km) and do not account for wildfires that can destroy restoration investments (planted trees), yet also initiate early seral conditions that favor natural recovery. Here, we examined soil compaction (bulk density) and tree regeneration density in burnt and unburnt seismic lines within mesic upland forest types and compared these to adjacent (paired) forest controls. Bulk density on seismic lines increased by 34% compared to undisturbed adjacent forests, but was not severe enough to impede regeneration. Despite increases in compaction, regeneration density was 19% higher on lines than in adjacent forests. Specifically, regeneration density averaged 19,622 stems/ha in burnt lines, 11,870 stems/ha in unburnt lines, 16,739 stems/ha in adjacent burnt forest, and 6,934 stems/ha in adjacent unburnt forest where regeneration rates are expected to be lower. We suggest that leave-for-natural recovery (passive restoration) of seismic lines can be expected post-fire in mesic upland forests with even the majority of unburnt seismic lines recovering to densities above the 5,000 stems/ha guidelines. Active restoration treatments using intensive silviculture treatments should therefore only be considered where recovery is not observed or wildfire likely.

Mitigation of Greenhouse Gas Emissions with Biochar Application in Compacted and Uncompacted Soil

Biochar may offer a substantial potential as a climate change mitigation and soil improvement agent; however, little is known about its effects in fertile soils subjected to standard agricultural practices. The aim of this short-term (60 days) lab experiment, under controlled temperature and soil moisture regimes, was to investigate the interaction between soil compaction and fertiliser and biochar addition in relatively fertile Luvisol. Three different biochar types and two soil compaction levels were investigated to describe their interactive effect on soil greenhouse gas emission (GHG). A very strong effect of soil compaction on N2O emission (+280%) and an interaction with biochar were found. The cumulative N2O emissions from the compacted soil were higher (from +70 to +371%, depending on the biochar type) than the uncompacted soil. Soil compaction resulted in a faster onset and a faster decrease of N2O production. Biochar did not affect the temporal dynamics of N2O evolution from either soil. The addition of digestate/crop biomass biochar has resulted in a significant increase in CO2 evolution both in compacted and uncompacted soils, compared to softwood from spruce (mixture of branches and wood chips) and wood pallets from softwood (spruce without bark) biochar. In the compacted soil, NH4+ availability was positively related to N2O efflux, and CO2 emission was positively correlated to both NH4+ and SOC content. An increase in GHGs as a result of an increase in NH4+ availability was seen both in compacted and uncompacted soils, while the rates of N2O emission were modified by biochar type. Our results show a strong interaction between biochar and soil conditions and a strong effect of biochar type on GHG emissions from agricultural soils.

Lasting Effects of Soil Compaction on Soil Water Regime Confirmed by Geoelectrical Monitoring

AbstractDespite its importance for hydrological and ecological soil functioning, characterizing, and quantifying soil structure in the field remains a challenge. Traditional characterization of soil structure often relies on point measurements, more recently, we advanced the use of minimally invasive geophysical methods that operate at plot‐field scales and provide information under natural conditions. In this study, we expand the application using geoelectrical and time‐domain reflectometry (TDR) monitoring of soil water dynamics to infer impacts of compaction on soil structure and function. We developed a modeling scheme combining a new pedophysical model of soil electrical conductivity and a soil‐structure‐informed one‐dimensional water flow and heat‐transfer model. The model was used to interpret Direct Current (DC)‐resistivity and TDR monitoring data in compacted soils at the Soil Structure Observatory (SSO) located in the vicinity of Zürich, Switzerland. We find that (1) soil compaction leads to a persistent decrease in soil electrical resistivity and (2) that compacted soils are typically drier than non‐compacted soils during long drying events. The main decrease in electrical resistivity is attributed to decreasing macroporosity and increasing connectivity of soil aggregates due to compaction. Higher water losses in compacted soils are explained in terms of enhanced evaporation. Our work advances characterization of soil structure at the field scale with electrical methods by offering a physically based explanation of the impact of soil compaction on electrical properties and by interpreting DC‐resistivity data in terms of soil water dynamics.

Rangeland Degradation Impacts on Vegetation Cover, Soil Properties and Ecosystem Functioning in an Arid and Semi-Arid Climate, South Africa

The negative effect of soil erosion and soil compaction is well documented for the purpose of optimum rangeland functioning, while the impact of rangeland degradation on effective soil depth is seldom quantified. The aim of this study was to quantify the response of vegetation cover and soil properties, particularly effective soil depth and soil texture to rangeland degradation. Forty-one farms were sampled in the arid and semi-arid climate of South Africa. Within these farms, data was collected over a vegetation degradation gradient. Results showed a significant decline in relative basal cover (94% ± 15% to 39% ± 17%) and soil depth (90% ± 14% to 73% ± 24%) as rangeland degraded. Soil texture changes over the degradation gradients vary for different homogeneous vegetation types. Indications regarding the loss of a functioning rangeland ecosystem were also demonstrated, using objective long-term relations between rangeland conditions and grazing capacity. The study highlights the importance of sustainable rangeland management practices to reduce the loss in effective soil depth and to ensure the sustainable utilization of the rangeland ecosystem. These results can probably extrapolate to other arid and semi-arid rangelands worldwide.

Effects of conservation tillage, controlled traffic and regulated deficit irrigation on soil CO2 emissions in a maize-based system in Mediterranean conditions

Conservation tillage is promoted as a potential agriculture practice to reduce carbon dioxide (CO2) emissions but little is known on its impact in irrigated Mediterranean conditions, and particularly, when combined with controlled traffic, adopted to avoid soil compaction effects on the crops, and with regulated deficit irrigation (RDI), adopted to conserve water. CO2 effluxes were measured during the 2016/2017 and 2017/2018 irrigated maize-cropping and fallow periods on a long-term tillage experiment established in Cordoba (Spain) in which two tillage systems, conventional with residues incorporated (CTR) and zero tillage with surface residues (ZTR), are compared, both combined with controlled traffic. Additionally, two irrigation treatments were introduced: full irrigation (FI) and RDI. We hypothesized that ZTR paired with RDI would make this irrigation strategy more effective for reducing CO2 emissions. Although tillage and traffic affected CO2 effluxes, RDI did not in spite of saving 100 mm of water. Frequent irrigations maintained similar superficial soil conditions in FI and RDI. In the short term, soil CO2 effluxes were higher in CTR than in ZTR after soil preparation and during crop growth, although only significantly in the first case. However, accumulated CO2 emission during the cropping period (163 days) was 1.8 times higher for CTR than ZTR (2126 and 1177 g m−2, respectively). The accumulated emission during the fallow period (202 days) was less relevant and similar for both systems (628 g m−2). Spatially, crop lines emitted the double CO2 than furrows during the cropping period in both tillage systems, and in ZTR during the fallow, showing the relevance of the measuring point locations. Three diurnal soil CO2 efflux curves supported the results. In irrigated Mediterranean maize crops, ZTR combined with controlled traffic can be an efficient soil management system to reduce CO2 emissions, and can be paired with RDI for water saving.

Numerical Modelling of Induced Stresses in Buried Corrugated Metal Structures due to Compaction Efforts

An essential element of composite soil-structure pipe and/or culvert systems is the backfilling process, where compaction efforts are applied to newly placed soil layers surrounding flexible corrugated metal pipes/culverts (CMPs/CMCs). Compaction of the layers of the side backfill has a significant effect on the culvert wall response, based on the relative stiffness of the buried structure and the backfill soil material. In the literature, various compaction modelling procedures are described which compute lateral stresses induced in flexible buried culverts due to the backfill compaction. However, a disadvantage of many of these procedures is the simulation of the soil material as an elastic medium, since this results in rebound behavior following removal of the compaction loads. This paper investigates several procedures for applying compaction efforts in two-dimensional finite element analyses (FEA). New numerical modelling procedures are proposed to simulate the effect of soil compaction on buried culverts, including modifications to existing modelling procedures to improve their ability to capture the culvert response. The numerical modelling results are compared with the results of three full-scale tests of buried corrugated metal structures. These structures include an arch pipe and an open-bottom arch culvert in Sweden and a horizontal ellipse pipe in Canada. Based on the analyses, this study concludes that the most effective methods for applying compaction are the use of a vertical surface loading procedure or a prescribed vertical displacement procedure. These procedures provide the best fit with the deformation and the bending moment measurements recorded in the field.

Effects of soil compaction and moisture on the growth of Juncus tenuis

AbstractJuncus tenuis Willd. is a warm‐season, perennial weed of turfgrass. In wet and compacted soils, it is well documented, yet little is known regarding the interaction effects of compaction and soil moisture on its rooting and foliar growth. A greenhouse experiment examined the effects of soil compaction and moisture on the above‐ and belowground growth of J. tenuis. The experimental design was completely randomized with a 3 × 3 arrangement with four replications and two runs. Factors included soil compaction (bulk densities of 1.56, 1.77, and 2.00 g cm–3) and soil moisture (10.9, 27.9, and 59.6% volumetric water content). Juncus tenuis was transplanted into pots, acclimated for 7 d, and subjected to the treatments for a 10‐wk period. Foliar growth was harvested every 2 wk and root growth was destructively assessed. Cumulative foliar and root biomass varied in response to compaction and soil moisture; however, no significant soil moisture × compaction interactions were detected. The effect of compaction on foliar and root biomass accounted for 15 and 12% of the explained variation, respectively. Increasing the bulk density from 1.56 to 2.00 g cm–3 reduced foliar and root biomass by 29 and 40%, respectively. Soil moisture accounted for ≥84% of the variation in foliar and root biomass. Increasing the soil moisture from 10.9 to 59.6% increased foliar and root biomass by 150 and 230%, respectively. The results suggested that cultural practices that prioritize soil moisture modification while alleviating compaction may reduce the presence of J. tenuis within maintained turfgrass.

Simulation of Soil Compaction by a Tractor Passing

Several methods for agricultural soil compaction evaluation are known. However, there is a lack of knowledge about a soil elasticity, which could be an important factor for final level of compaction. The paper deals with a possibility of evaluation of soil elasticity using automatic computerized oedometer. A simulation of tractor passing was performed as a part of research focused on the monitoring of soil conditions in vineyards. Cyclic loading test of five loading cycles (loading 300 kPa and un-loading 5 kPa) was performed and vertical deflection was observed, which changed in dependency on change of vertical stress. Course of vertical deformation indicates the ability of soil to relax when the load subsides. The paper presents pilot results, that show good potential of using oedometer for soil elasticity evaluating. Information on the elastic behaviour of soil will make it possible to design and apply means for improving soil elasticity and thus help to mitigate the effects of soil compaction.

Effects of soil compaction on grain yield of wheat depend on weather conditions

The use of heavy farm machinery has resulted in widespread soil compaction in many regions of the world. Compacted soil limits the access of crops to soil water and nutrients and is expected to reduce crop productivity, but the influence of weather conditions on the interactions between compacted soil and crop productivity is unclear. Furthermore, early vigor has been regarded as a promising trait for improving the yield of crops grown under edaphic stress such as soil compaction. We aimed to assess the combined effects of soil compaction and contrasting weather conditions on growth and grain yield of spring wheat, and to evaluate the association between early vigor and grain yield under temporal variations of the soil physical conditions. Nine spring wheat genotypes were grown on compacted and non-compacted soils during two cropping seasons with contrasting weather conditions in Central Sweden. Compared to the non-compacted treatment, soil compaction increased the relative growth rate of shoot biomass from sowing to stem elongation, and from stem elongation to flowering in the drier year (2018), but decreased the same traits in the wetter year (2019). The contrasting effects of soil compaction on shoot growth in the two years could be explained by soil moisture and penetration resistance associated with the interactive effects of soil compaction and weather condition. Higher early vigor, here indicated by higher relative growth rate from sowing to stem elongation, was associated with reduced grain yield under the progressively drying and hardening soil conditions during the entire cropping season of both years. We conclude that the interactive effects of soil physical and weather conditions need to be considered when evaluating the impact of soil compaction on crop growth and productivity. The potential of early vigor to increase grain yield is strongly influenced by the temporal dynamics of soil physical conditions.

The Effects of Soil Compaction and Different Tillage Systems on the Bulk Density and Moisture Content of Soil and the Yields of Winter Oilseed Rape and Cereals

Progressive soil compaction is a disadvantage of intensive tillage. Compaction exerts a negative impact on the physical properties of soil and decreases crop performance. The adverse effects of soil compaction can be mitigated by replacing conventional tillage with simplified tillage techniques. Simplified tillage exerts a protective effect on soil, reduces production costs and preserves agricultural ecosystems. The aim of this study was to determine the influence of compaction and different tillage methods on the bulk density and moisture content of soil. The experimental factors were as follows: Soil compaction before sowing (non-compacted control treatment and experimental treatments where soil was compacted after the harvest of the preceding crop) and four different methods of seedbed preparation in a three-field rotation system (winter oilseed rape, winter wheat, spring barley). The influence of compaction on the bulk density and moisture content of soil varied across the rotated crops and their developmental stages. Soil compaction had no significant effect on the analyzed parameters in the cultivation of winter oilseed rape. In treatments sown with winter wheat, soil compaction resulted in significantly lower soil density and significantly higher soil moisture content. In plots sown with spring barley, soil compaction led to a significant increase in the values of both parameters. The average bulk density of soil after various tillage operations in the examined crop rotation system ranged from 1.49–1.69 g·m−3 (winter oilseed rape), 1.47–1.59 g·m−3 (winter wheat), 1.47–1.61 g·m−3 (spring barley). The bulk density and moisture content of soil were lowest after conventional tillage (control treatment) and higher after simplified tillage. Regardless of soil compaction, the greatest reduction in winter oilseed rape yields was noted in response to skimming, harrowing and the absence of pre-sowing plowing. Spring barley yields were higher in non-compacted treatments, whereas the reverse was observed in winter wheat. Chisel plowing and single plowing induced the greatest decrease in wheat yields relative to conventional tillage. Single plowing significantly decreased the grain yield of spring barley relative to the tillage system that involved skimming and fall plowing to a depth of 25.

Evaluation of Leaf Litter Mulching and Incorporation on Skid Trails for the Recovery of Soil Physico-Chemical and Biological Properties of Mixed Broadleaved Forests

Engineering applications can be used to mitigate the adverse effects of soil compaction and amend compacted soils. Previous literature has highlighted the beneficial effects of interventions such as litter mulching and incorporation on skid trails. However, little is known about the effectiveness of these alternatives in restoring forest soil quality after forest logging. The objective of this study was to properly elucidate the effects of the above mentioned soil protection methods, litter incorporation before skidding (LI) and litter mulching after skidding (LM), on the recovery of compacted soil’s physico-chemical and biological properties on skid trails over a 2-year period in the Hyrcanian forests of Iran to identify the best option for restoration intervention. The litter used in both methods consisted of dried leaves of the hornbeam and maple tree in three intensities of 3, 6, and 9 Mg ha−1. The results showed that the application of both methods (LI and LM) significantly improved the soil properties when compared to the untreated skid trail. Results showed that the recovery values of soil properties in the LI treatments were significantly higher than those of the LM. The recovery values of soil properties by 6 and 9 Mg ha−1 were significantly higher than those of 3 Mg ha−1, while the differences were not significant between 6 and 9 Mg ha−1. Our findings showed that soil properties were partially recovered (70–80%) over a 2-year period from treatment, compared to untreated, but the full recovery of soil properties required more time to return to the pre-harvest value. Overall, the results of this study demonstrated that the application of soil protection methods accelerates the process of recovering soil properties much faster than natural soil recovery, which can take more than 20 years in these forests.

Soil compaction and organic matter removal effects on soil properties and tree growth in the Interior Douglas-fir zone of southern British Columbia

Silviculture systems and associated forest harvesting practices that affect the level of soil compaction and organic matter retained on a site will cause changes to soil properties and processes that may affect the growth of planted trees. We present results for soil conditions and tree growth after 15 years for 6 Long-term Soil Productivity Study (LTSP) installations in 2 distinct regions of the Interior Douglas-fir (IDF) biogeoclimatic zone in southern British Columbia (BC). In a 3 × 3 factorial design, three levels of compaction and organic matter removal were replicated in two distinct IDF regions that varied in parent material, but with similar climates. Each treatment was then split and planted with two different species, Douglas-fir and lodgepole pine. In each region, three unique sites (block), all within a radius of 50 km from one other, were installed with the same combination of treatment and species for a total of six replicates, three in each of two regions. Across IDF regions, tree heights on calcareous soils in the Rocky Mountains of south-eastern BC were 36% lower for Douglas-fir and 23% lower for lodgepole pine than on more acidic soils on the Thompson Plateau. There were varying differences across treatments in soil and foliar nutrient concentrations between IDF regions, primarily from regional parent material differences. However, nutrient deficiencies were apparent in both regions and may have limited growth, especially on the more calcareous sites. Increases to soil bulk density (27%) 1 year after compaction did not impact tree survival, height at Year-15, or chemical properties in foliar tissue or soil. Fewer growing season frost events and increased soil water availability during the seedling establishment period was a likely reason for a 25% increase in Douglas-fir survival at Year-15 with the whole tree + forest floor removal (OM3) treatment. However, whole tree + forest floor removal (OM3) also produced a 13–19% reduction in soil N, S, K, and mineralizable N when compared to both stem-only (OM1) and whole tree (OM2) harvesting treatments that kept the forest floor intact. Effects on forest productivity from soil compaction after 15 years appear to be overshadowed by the more prominent effect of organic matter removal treatments during stand establishment and early growth. Future work at these installations focusing on nutrient budget, forest health, and ecosystem carbon stock differences across treatments will provide valuable insight into silviculture and harvesting practices for different species and regions in the dry forests of southern BC.

Effect of Soil Compaction on Growth, Yield and Quality of Sugarcane (Saccharum Officinarum L.) Crop and It is Management: A Review

Sugarcane is a tall growing monocotyledonous crop plant that is cultivated in the tropical and subtropical regions of the world primarily for its ability to store high concentrations of sucrose, or sugar, in the internodes of the stem. Sugar is not the only product of the cane that is used in the production of various products. Both the pulp and the outer portions of the stalk can be utilized in the creation of woven furniture, cardboard and other paper products, and disposable eating utensils. In spite of the importance of the crop there are many factors which cause the decrease in sugarcane productivity such as climate change and declining in soil fertility as an impact of conventional soil management. The use of heavy machinery during planting, harvesting and transporting operations in fine textured soils has led to the concern that subsoil compaction may decline long term productivity. Hence this leads to affects soil physical fertility, particularly storage and supply of water and nutrients, through increasing soil bulk density, decreasing porosity, increasing soil strength, decreasing soil water infiltration, and water holding capacity, and all of these processes lead to changes in plant physiology of sugarcane that leads to effect sugarcane growth, decline sugar yield and quality. Among many other management options of soil compactness; Soil Water Potential, Soil characterization before cultivation of land, Soil Tillage, passages of machine across the field and crop rotation is the major one. Keywords : Sugarcane, Yield, Quality and Soil Compaction DOI: 10.7176/JEES/11-5-02 Publication date: May 31 st 2021

How does soil compaction alter nitrous oxide fluxes? A meta-analysis

Nitrous oxide (N2O) is a potent greenhouse gas and precursor of ozone layer depletion. Managed terrestrial ecosystems are major anthropogenic sources of N2O, primarily generated in the soil. The physical makeup of the soil interplays with the underlying biochemistry that produces N2O. Therefore, it has been conceptualized that either compacting or loosening the soil will alter N2O emissions; however, a unified framework of these relationships is yet to be established. Here, we compiled, reviewed and analyzed available field studies that have evaluated how applied compaction or alleviation of compacted soils impacts N2O emissions. Of the 108 available pairwise comparisons, 82 % of the cases showed detrimental increases in N2O emissions caused by increased compaction. Overall, N2O emissions nearly doubled because of soil compaction effects (P < 0.05). This doubling of N2O emissions was linked to a relative reduction of 9 % in soil porosity (i.e., 0.05 cm3 cm−3) caused by applied compaction. This linkage to soil porosity was clearly evident in both croplands and pastures. Across the managed terrestrial ecosystems evaluated, the strongest relative effects of compaction on N2O emissions were found in forest and pasture soils. Overall, N2O emissions in forest soils showed a fivefold increase caused by compaction (P < 0.05; n = 11). This massive response in forest soils can be attributed to: i) their low N2O emission baseline; ii) their acidic pH, which intrinsically favors N2O emissions; iii) having some of the heaviest traffic loads found across our meta-analysis (e.g., 16 Mg); and iv) an increase in soil microporosity. Pasture soils also displayed substantial compaction effects on N2O emissions, with a threefold increase (P < 0.05; n = 25). This was explained in part by the elevated nitrogen input rates in pastures (e.g., 600–1000 kg N ha-1). Conversely, alleviation of soil compaction by implementing controlled traffic farming (CTF) in vegetable and grain croplands reduced N2O emissions consistently in all available pairwise comparisons (P < 0.05; n = 19). At the field scale, CTF greatly decreased N2O emissions by one-third compared with farmlands managed with conventional random traffic (4.48 versus 2.86 kg N2O-N ha-1). However, after reviewing the available literature, we witnessed a paucity of information about how long it takes for soils to self-alleviate from the detrimental effects of compaction on N2O emissions. Additionally, insights gained through meta-analysis revealed the interplay of soil compaction with underlying heavy textures, acidic pH, and reduced porosities, which collectively exacerbate N2O emissions. Nevertheless, these complex interactions operate differentially across contrasting land use options.

A meta-analysis of the impact of traffic-induced compaction on soil physical properties and grain yield

Soil compaction caused by wheel traffic is a major driver of soil degradation in modern agriculture and thus, a threat to agricultural sustainability. To improve the predictive capacity of compaction models and to support decision-making that implements site-specific practices for ameliorating soil compaction effects in modern agriculture, we need quantitative syntheses of the effect of soil compaction on soil physical properties and crop types. In this work, we used a meta-analytical approach to summarize results from 51 published articles on the impacts of soil compaction attributed to machinery axle load, wheel passes, compaction events and tire inflation pressure on soil bulk density (ρb), degree of compactness (DC), penetration resistance (PR), volume of water filled pores at field capacity (θFc), air permeability (ka) at field capacity, saturated hydraulic conductivity (ksat), and grain yield of corn (Zea mays L.), wheat (Triticum aestivum L.), barley (Hordeum vulgare L.) and soybean (Glycine max L.). Results from this meta-analysis (MA) showed that compaction increased soil mechanical strength shown by increased soil ρb, DC and PR. However, an increase in soil strength was more pronounced in the medium- and coarse-textured soils, and mainly in the topsoil (0–30 cm depth). Penetration resistance for the non-compacted soil (control) treatment was 1.21 MPa for the coarse-textured, 1.11 MPa for the medium-textured and 0.93 MPa for the fine-textured soils. Soil compaction on average, increased PR by 99, 94 and by 41 percent in the medium-, coarse- and fine-textured soils. Compaction decreased hydraulic conductivity characterized by ka and ksat from the topsoil down to the subsoil (>40 cm depth), and grain yield of corn, wheat, barley, and soybean. Overall, compaction decreased grain yield on average by 6–34 percent. Findings of the MA suggest that soil hydraulic properties may be more sensitive indicators to reflect the impact of soil compaction on soil structure and pore system functions in the soil profile. Future efforts should place a greater emphasis on the publication of complete metadata that allows replication and accurate comparison of results across studies and on providing open access to original datasets that can be used to improve our understanding of the effect of traffic-induced compaction on soil functioning, including crop production.

Implantation and biomass of Avena sativa L., two methodologies of preparation, tillage soil and direct sowing

Autumn sowing of oats and other winter species is the alternative to balance the annual dry matter production in Uruguay, with fast forage availability in 60 to 70 days and high nutritional quality. The objective of this research was to evaluate the implantation, biomass production and effect of soil compaction, on the production of oats in two soil conditions, intensive tillage and direct sowing, with two doses of fertilizer, in rain-fed. The experimental design was randomized blocks with 20 repetitions of 50x10cm for implantation and 18 repetitions of 7x4m, for biomass production. The cultivar used was La Estanzuela 1095a. It was determined: implantation of crop, biomass production and the resistance of soil to the penetration. The germination in tillage soil (TS) and direct sowing (DS), showed 91.7 and 76.6% emergence, respectively. The forage production showed no significant differences between TS and DS. The statistical analysis of the green matter data showed a significant difference between the treatments for the control plots and 50 units of nitrogen. The penetration resistance for the 1 cm-2 cone showed significant differences at 15 cm depth, while for the 5 cm-2 cone the significant differences were at all depths, with DS being greater. The TS treatment showed lower resistance to penetration, better implantation and greater biomass production.