Compaction Levels Research Articles

Are the yield of sunflower and Paiaguas palisadegrass biomass influenced by soil physical quality?

Soil compaction affects physical soil properties, which in turn influence crop growth, development and yield. The present study tested the hypothesis that the yield of sunflower achenes and Paiaguas palisadegrass biomass are influenced by soil physical properties. The effects of compaction were measured by the least limiting water range (LLWR), and its relationship with crop yield were studied. The experiment was conducted in the Rio Verde municipality, south-western Goias State, Brazil, on a Latossolo Vermelho Acriférrico típico (Typic Haplustox) soil and in accordance with a randomized complete block design, in which the treatments consisted of compaction levels established by zero, two, 10, and 30 passes of an agricultural tractor (with four replicates each). In the subplots, sunflower and Paiaguas palisadegrass were grown as monocropping and intercropping systems. The following indicators of soil physical quality were determined: bulk density (Bd), the LLWR, the Bd/alert bulk density of the LLWR (Bdalert) ratio, and the Bd/critical bulk density of the LLWR (Bdc) ratio. The correlations of these indicators with crop yield were calculated to define critical resistance values specific to each crop. The LLWR adequately described the physical quality of the soil resulting from compaction and was significantly correlated with crop yield. The relationship between sunflower and Paiaguas palisadegrass yield was modelled by a second-order equation featuring Bd and the Bd/Bdalert ratio (R2 = 0.77, ** and 0.74 **, respectively), with the greatest yield recorded when the Bd/Bdalert ratio was 1.0. Sunflower cultivation was extremely sensitive to soil compaction: when sunflower was grown as a monoculture or intercropped with palisadegrass, its yield decreased by 50 % or 80 %, respectively. However, the Paiaguas palisadegrass yield was influenced little by soil compaction. The limiting penetration resistance values for sunflower and Paiaguas palisadegrass were 1.5 MPa and 4.2 MPa, respectively.

Characterization of intra‐ply shear behaviors of unidirectional prepregs during hot diaphragm forming process

AbstractIntra‐ply shear is the most important deformation mode in composite sheet forming. In this study, the intra‐ply shear behaviors of cross‐ply unidirectional carbon fiber/epoxy prepregs under double diaphragm compaction at different temperatures and cross‐head rates were investigated by a home‐made testing system. The experimental test results indicate that uniform temperature distribution and low forming speed in double diaphragm process help to obtain high‐quality products. A modified model based on the temperature, cross‐head rate and the level of compaction was proposed for shear angle prediction. Then fifth‐degree polynomial and power functions combined with two rate‐independent theories were used to calculate the shear force and modulus. The shear force and shear modulus are strongly influenced by the function that describing the relationship between the shear force and shear angle.

Tree preservation during construction: An evaluation of a comprehensive municipal tree ordinance

In the United States, urban forests represent 35 % of all urban land cover, and deliver benefits to nearly two-thirds of the population. As global urban populations continue to rise, however, redevelopment is continually reported as a major factor in reduced canopy cover. While urban trees provide us with measurable benefits when adequately maintained, their costs when not cared for remains poorly understood. In order to safeguard the benefits that urban forests provide, municipalities have begun to introduce ordinances with the intention to protect and manage trees within their community. The aim of this study was to better understand the condition and survival outcomes of residential trees intended to be preserved through a municipal tree preservation ordinance. The results of this study found that a comprehensive tree preservation ordinance can successfully protect tree and soil health during and after residential development occurs. This is evident through an overall preservation rate of nearly 75 %, having found no correlation between proximity to newly developed foundation and observed tree condition or mortality, and the discovery of healthy soil compaction levels within tree protection areas and the critical root zones of preserved trees. Collaborative research as demonstrated by this project can help both academics and professionals gain a better understanding of how to best manage their own urban forests.

On the effect of compaction on the progression of concentrated leaks in cohesive soils

The purpose of this study is to conduct hole erosion tests (HETs) to better understand the progression of concentrated leaks in compacted soils. While samples with high levels of compaction have been extensively tested for their erosion characteristics in the literature, soils at lower compaction levels have not yet been extensively assessed. This study aims to better understand the internal erosion behaviours of low-compacted soils during the progression of concentrated leaks. To this end, compaction tests are performed on various mixtures of Sydney sand and kaolin clay samples at different compaction moisture contents (i.e. moisture content at the time of compaction) and compaction efforts. Optimum moisture contents for different compaction efforts are subsequently determined. Samples for the HET are then prepared at various compaction densities and moisture contents to obtain their rate of erosion due to concentrated leaks. Results from testing show that if appropriate moisture contents are used, low-compacted samples do not necessarily show higher erodibility potential. The results can help in the determination of the most cost-effective, yet stable, materials for use in practice, for example in the core of embankment dams.

Chromatin Remodelers in the 3D Nuclear Compartment.

Chromatin remodeling complexes (CRCs) use ATP hydrolysis to maintain correct expression profiles, chromatin stability, and inherited epigenetic states. More than 20 CRCs have been described to date, which encompass four large families defined by their ATPase subunits. These complexes and their subunits are conserved from yeast to humans through evolution. Their activities depend on their catalytic subunits which through ATP hydrolysis provide the energy necessary to fulfill cellular functions such as gene transcription, DNA repair, and transposon silencing. These activities take place at the first levels of chromatin compaction, and CRCs have been recognized as essential elements of chromatin dynamics. Recent studies have demonstrated an important role for these complexes in the maintenance of higher order chromatin structure. In this review, we present an overview of the organization of the genome within the cell nucleus, the different levels of chromatin compaction, and importance of the architectural proteins, and discuss the role of CRCs and how their functions contribute to the dynamics of the 3D genome organization.

Dynamic Characteristics of Coarse Aggregates within Epoxy Asphalt Mixture during Superpave Gyratory Compaction

Abstract To investigate the dynamic characteristic of coarse aggregates within epoxy asphalt mixture, this study conducted a virtual simulation of the Superpave gyratory compaction (SGC) test based on the discrete element method and artificial neural network. A three-dimensional compaction model of epoxy asphalt mixture was built and verified, considering the irregular polyhedral morphology and the elastic property of coarse aggregates, the mastic volume and the thermosetting and viscoelastic properties of epoxy asphalt mastic. Subsequently, the SGC numerical model was applied to analyze the particle velocity, porosity distribution, and particle force status at different compaction levels. Results demonstrate that the compactness increment mainly depends on the movement and rotation of aggregates in the early stage, and rotation of aggregates in the later stage. The existence of gyration angle and the internal structure of epoxy asphalt mixture can affect the dynamic behavior of aggregates. The structure of mixture in the central area is relatively more stable during compaction, and the peripheral area of the specimen is more difficult to compact.

Гормональній статус та сперміологічні параметри У пацієнтів з мікрохірургічним втручанням при необструктивній азооспермії

Azoospermia occurs in approximately 10% of men with infertility and can occur due to obstruction of the reproductive tract (obstructive azoospermia) or lack of sperm production. Assessing the hormonal status of men can provide prognostic information on the effectiveness of surgical sperm removal for their further use in assisted reproductive technology programs. Before performing a testicular biopsy to establish a histological diagnosis and search for sperm in patients with non-obstructive azoospermia, it is advisable to assess the chances of obtaining sperm. The purpose of the study was to assess hormonal levels and sperm parameters during microsurgery in men with non-obstructive azoospermia. Material and methods. We analyzed the medical records of 45 men with non-obstructive azoospermia who underwent micro-TESE in the period from 2016 to 2019. We noted the data on the age of patients, their hormonal profile (level of follicle-stimulating hormone, luteinizing hormone and testosterone) were analyzed and morphofunctional characteristics of the obtained spermatozoa. Results and discussion. In our study, testosterone levels were significantly higher in patients in group 1, which may be due to the fact that men in this group were significantly younger. Sperm were removed from 10 (22%) patients with non-obstructive azoospermia. The probability of sperm removal decreased with increasing age of patients. The average concentration of sperm in the samples was (2.3±0.8) million, of which active (18.0±0.3)%. Morphological analysis of sperm revealed that the frequency of abnormalities of the head was 19.9±2.45, neck – 13.69±1.49, tail – (5.96±1.52)%. Mixed pathology, which involved defects of the head, neck and middle part were at the level of (34.6±4.21)%. The frequency of sperm neck abnormalities was (13.7±1.5)%. The most numerous were abnormalities associated with the presence of cytoplasmic residues on the surface of the sperm. The number of sperm with tail pathology was at the level of (5.9±1.5)%. In general, the mixed pathology, in which defects of the head, neck and middle part were involved, was at the level of (34.6±4.2)%. Conclusion. In this study, the frequency of positive micro-TESE, i.e. surgical procedures after which sperm were removed, was 22.2%. Morphological analysis of the drugs revealed that among the identified pathologies, most of them were sperm with the presence of one large or several small vacuoles. The number of vacuoles, their size and shape reflect defects at the level of compaction of the sperm nucleus. It has been shown that embryos formed after fertilization of oocytes with such sperm do not undergo reproductive selection and can stop in the early stages of development

The Bearing and Breakage Characteristics of Crushed Stone Aggregates in the Bedding Course of Permeable Roads

The current study of permeable roads helps address urban flooding in Chinese cities caused by frequent heavy rainfall and build smart cities with sponge-like functionality. Crushed stone is widely used in constructing the bedding course of permeable roads because it has good water permeability. Experiments on the compaction of crushed stone were carried out by considering the impact of particle size and gradation to examine the strength and particle breakage characteristics of crushed stone and evaluate its use as the aggregate in the bedding course of permeable roads. The compaction process can be divided into two stages, i.e., the preliminary compaction stage and the particle crushing and intensive compaction stage. The latter consists of an alternating cycle of compacting and crushing. The particle size distribution after crushing can be described analogously to the Talbot continuous gradation equation. Single particle size samples are subject to earlier and stronger particle breakage than the mixed particle size sample, which are affected by both compaction level and loading speed. This study has important application value, and it provides experimental support for the study of materials for urban permeable roads.

Characterization of the interconnected pore and its relationship to the directional permeability of porous asphalt mixture

The efficiency of the water flow path (or the interconnected pore) within the porous asphalt (PA) mixture could affect the permeability performance significantly. This study aims to quantify the interconnected pore of the PA mixture and find the evidence for the relationship between the pore microstructure and the permeability performance. The laboratory experimental matrix includes six PA mixtures with air void content varying from 18.4% to 22.9% by altering the gradation, fiber contents and compaction levels. A self-designed directional permeability test was used to measure the permeability of the PA mixture in both vertical and horizontal directions. Industrial X-ray CT scanning and image analysis method were used to analyze the interconnected air void content (Vai) and average tortuosity (Ta) of the PA mixture in both horizontal and vertical directions. Results indicate that the self-designed directional permeability test could measure the vertical and horizontal permeability coefficient simultaneously. The vertical and horizontal permeability of the PA mixture are different. The PA mixture with addition of fiber presents the highest Ta and the PA mixture with under-compacted condition presents the highest Vai among the six PA mixtures. Based on the correlation analysis, it was found that the directional permeability of the PA mixture is influenced by the coupling effect of the Vai and Ta.

Tracking the Biological Incorporation of Exogenous Molecules into Cellulose Fibers with Non‐Radioactive Iodinated Glucose

AbstractSemi‐synthetic biological fabrication explores biological systems and their biosynthetic pathways as inspiration for designing precursor analogs that can be metabolized in a similar manner as the natural substrates by organisms to yield new materials with tailored properties. Here we report the biological incorporation of a metabolizing iodinated glucose analog (2‐Deoxy‐2‐iodo‐D‐glucose, DIG) into Gossypium hirsutum cotton fibers in an ovule in‐vitro model. Structural modifications occur at the level of crystallite arrangement and compaction, with amorphization of the fibers and alteration of the H‐bond network between the cellulose nanofibrils. We further show that DIG can serve as a non‐radioactive micro computed tomography contrast agent (μCT). The fibers act as glucose sinks that accumulate DIG, enabling its detection by μCT. Quantitative analysis shows that the fibers are more oriented when incubated with DIG. This work demonstrates the advantages of using higher organisms for biological in‐situ transformation of economically important raw materials over conventional chemical surface modification processes, thereby providing a scientific foundation for implementing future alternatives and sustainable manufacturing strategies towards a bio‐based economy.

Precrops alleviate soil physical limitations for soybean root growth in an Oxisol from southern Brazil

The impact of soil compaction on soybean root growth and grain yield can be alleviated by the presence of biopores and root channels in the soil profile. We hypothesize that cover crops (ruzigrass and oats) are better than grain crops (wheat and maize) to reduce the soil physical limitation to soybean root growth. We aimed to identify which precrops have higher potential to reduce the mechanical and water stresses resulting from soil compaction and soil desegregation, and to enhance soybean (Glycine max L) root growth and yield in an Oxisol (Rhodic Eutrudox), with clayey soil texture. Soybean was grown after four precrops (ruzigrass, oats, wheat, or maize), under four soil compaction levels [soil chiselling (MTC), no-tillage (NT), NT additionally compacted with four passes of a tractor (NTCT), and NT additionally compacted with eight passes of a grain harvester (NTCH)]. Soil physical attributes (bulk density, macroporosity, water-filled pore space and soil penentration resistance) in the soil profile (0−50 cm) and soybean components (grain yield, cumulative root length density and root dry mass) were investigated. Soil physical attributes were improved over time due to the combined effects of natural wetting-drying cycles and biopores created by the roots of precrops. Ruzigrass increased soybean root biomass and length density, mainly at deeper soil layers of compacted treatments (NTCT and NTCH). The rate of increase of soybean root length density in the soil profile was higher after ruzigrass cultivation in comparison with maize and oats. Soil compaction effects on grain yield were partially (NTCH) or totally (NTCT) alleviated after two years and ruzigrass intensified the mitigation process. Ruzigrass also resulted in higher soybean yields in comparison with maize, whereas NTCH and MTC reduced yields in approximately 400 kg ha−1 (∼13 %) compared to NT and NTCT. Soil strengthening was more evident after ruzigrass and oats cultivation than maize or wheat cropping. Soil compaction in clayey Oxisols can be alleviated over time as a result of root channels provided by precrops combined with natural wetting-drying cycles. Among the evaluated precrops, ruzigrass is of particular interest, as it provides the most suitable soil physical environment for soybean root growth and grain yield. In contrast, chiselling was demonstrated to be a non-viable strategy to mitigate soil physical constraints for root growth and grain yields.

Effect of subsoil compaction on rooting behavior and yields of wheat

Soil compactions are widely dispersed in the world but tend to be the most prevalent, where heavy machinery is used in agriculture. The increasing use of heavy machinery is the primary cause of soil and subsoil compaction. The impact of subsoil compaction on root growth and yield of wheat (Triticum aestivum L) were evaluated during 2006 and 2007. Sub-soil compactions were created by three normal loads, i.e. 4.40, 6.40 and 8.40 kg and four number of passes of tractor, i.e. 1, 6, 11 and 16. The field was divided into 39 plots including a control plot, i.e. no passes of the tractor. The size of each plot was 400 square meter. A factorial randomized block design was followed in laying out the experiment and care was taken that all the 13 treatments and their replications are included in field experiments. It was observed that for all the compaction treatments in the field experiment on the wheat crop, 51–61% of wheat roots were confined in 0–15 cm, 17–20% in 15–30 cm and the rest 22–28% is below 30 cm soil layer. Sub-soil compaction reduced the wheat crop yields to a maximum of 23%. A statistical model is developed to predict crop yield considering the root length density of the crop. Average root diameters increased with the increase of the sub-soil compaction level. In sub-soil zone, average root diameter decreased with the increase of sub-soil compaction level.

Assessing frost heave susceptibility of gravelly soils based on multivariate adaptive regression splines model

Frost heave of railway roadbed leads to track geometry degradation during the cold season, seriously threatening the safety of high-speed trains. An accurate estimation of freezing-induced deformation in subgrade aggregates is thus critical to construction and maintenance of transportation infrastructure in seasonally frozen regions. This paper proposes a practical approach to assessing the frost heave susceptibility of gravelly soils under unidirectional freezing conditions. Typical frost heave tests are first performed on gravel columns in closed and open systems. The multivariate adaptive regression splines algorithm is subsequently applied to develop a predictive model for the normalized heave of a specimen. Experimental data of freezing tests were collected from this study and available literature to compile a dataset. A randomly selected subset is used for training, while the complement of the subset is intended for testing. Relative importance analysis and analysis of variance are finally performed to examine the general and coupling effects of initial moisture content, fines, relative compaction, and stress level on the frost heave susceptibility of compacted soil. Hopefully, the developed model and comprehensive analysis of coarse fills could assist railway agencies in understanding the appropriate characterization of frost heave and provide an evaluation guideline for optimized railway roadbed.

Effects of compaction on lead availability in contaminated soils with contrasting texture.

The effects of soil compaction on porosity(α), bulkdensity(ρs), and saturated hydraulic conductivity (Ksat) can create a physical barrier in the soil, reducing the vertical movement of toxic elements in the soil profile. However, the indirect effects of compaction in altering the forms and availability of heavy metals in soil have not been well-studied. This study examined the influence of compaction on forms of lead (Pb) in soils with contrasting texture. Four levels of compaction were imposed on a sandy loam and a clayey soil, which were artificially contaminated based on their maximum Pb adsorption capacity. Compaction had different effects on Pb forms depending on soil texture. In the sandy loam soil, compaction had a dual beneficial effect in mitigating the impact of Pb contamination, since it decreased Ksat, reducing metal transport to deeper soil layers, and also prevented transformation to more available Pb forms (soluble and exchangeable). Instead, there was an increase in the most environmentally stable forms of Pb (inner sphere adsorption on iron and manganese oxides). In the clayey soil, compaction caused a significant increase in soluble and exchangeable Pb, accompanied by a significant reduction in environmentally stable Pb (inner sphere adsorption on gibbsite and kaolinite). In addition, studies about Pb contents under compacted soil layers should be investigated, mainly in clayey soils with edible crops, and environmental remediation practices that involve the machinestraffic (for example, phytoremediation-successive cultivation of Pb-hyperaccumulating plants) should be used with care to minimise the compaction of clayey soils.

MicroRNA-based markers as a tool to monitor the barley (Hordeum vulgare L.) response to soil compaction

Plants are often exposed to adverse environmental conditions that can significantly interfere with their genomic response. Soil compaction induced by heavy field machinery represents a major problem for crop production mainly due to restricted root growth and penetration into soil and therefore reduced water and nutrient uptake by the plants. Tested hypotheses were to declare whether the plant‘s genome responds to soil compaction and whether the microRNA-based markers are suitable to determine this response. A long term field scale experiment was established in 2009 where different levels of soil compaction are researched from the soil and crop point of view. The analyzed barley (Hordeum vulgare L.) plants were collected during the growing season in 2019. The effect of soil compaction was analysed by four different DNA-based markers corresponding to miRNA sequences of dehydratation stress-responsive barley miRNAs (hvu-miR156, and hvu-miR408) and nutrition-sensitive markers (hvu-miR399 and hvu-miR827), within the leaf, stem and root tissues of barley plants. Our preliminary data support hypotheses that plant genome response was tissue-specific due to significant induction of the biomarkers to dehydratation and nutrition stress. The most affected part of the plant by dehydration, were roots and lack of nutrient supply was most pronounced on leaves.

Quantification of the soil stiffness constants using physical properties of paddy soils in Yangtze Delta Plain, China

The prediction of soil sinkage under wheels and tracks is of significant importance for determining the off-road vehicle performance and level of compaction of agricultural soils. Bekker's theory for pressure and sinkage relationship has been widely applied to estimate the vehicle mobility performance for designing off-road vehicles for deformable terrains. However, the Bekker's constants, which reflect the soil sinkage and behaviour of soil under load, vary significantly among soils. There is a paucity of studies on paddy soils in the plastic state. Furthermore, the determination of soil stiffness constants via pressure–sinkage tests is usually time-consuming. In this study, the impact of three soil physical properties, including soil water content, clay content, and density, on the soil stiffness constants for sinkage behaviour in paddy soils was assessed based on experimental results. Subsequently, numerical models were established to quantify the Bekker's stiffness constants measured from soil bin tests using soil physical properties. Three quadratic polynomial regression models were established and evaluated to quantify the three constants using soil water content, clay content, and density. The P values from goodness of fit tests suggested significant fit (p 0.05) between the simulated and experimental results. The established models were further validated using the soil samples with different physical properties. The comparisons between soil stiffness constants predicted using the model with laboratory-measured values indicated satisfactory model performances (R2 > 0.9). In this study, a simple and promising method was established to estimate soil stiffness constants using easy-to-measure soil physical properties. The model can provide a sound basis for the design and development of agricultural machinery in muddy and wet paddy fields.

Root and shoot growth in safflower as affected by soil compaction

Soil compaction, induced by no-tillage practices, can negatively impact soil properties important for plant growth. Compacted soils can restrict root growth depth, resulting in reduced crop yield. Although safflower (Carthamus tinctorius) has a deep root system, yield may still be affected by soil compaction. Therefore, this study aimed to evaluate safflower root and shoot growth when submitted to soil compaction in an Oxisol soil under controlled (greenhouse) and field conditions. Five soil bulk density measures were performed in a greenhouse (1.1, 1.2, 1.3, 1.4 and 1.5 Mg m–3). Four compaction levels (established by the number of passes of a farm tractor: 0, 1, 3, and 5 passes consecutively) were performed to evaluate the effect of soil compaction in the field. Root and shoot growth were measured after harvesting the plants. Safflower root growth was reduced when soil compaction increased from 1.1 to 1.5 Mg m–3 under controlled (greenhouse) conditions. In field conditions, we observed a decrease in root length, and fresh and dry matter in roots and shoots of safflower as the soil compaction increased to 5P (1.28 Mg m–3). The results of our study suggest safflower root and shoot growth can be impacted by soil compaction which could affect crop yield.

Influence of Induced Soil Compaction on the Growth, the Yield and the Soil Loss Resulting from the Groundnut Harvesting

The research was conducted to study the growth and the yield of the groundnut plant and to quantify the soil loss after groundnut harvesting as influenced by induced soil compaction. A ten kilogram of soil was packed in the pots with an initial bulk density of 1.05 Mg m-3, then it were compressed to1.57, 1.72, 1.88, 2.04, and 2.42 Mg m-3. The research was conducted in a completely randomized design with three replications. Groundnut seeds were sown in pots and the plant growth data were collected in a 2-week interval while force and energy of harvesting and soil loss due to groundnut harvesting were determined at 12 weeks after sowing. Data were analyzed using ANOVA and Fishers LSD at P= 0.05. Soil compacted to1.88 Mgm-3 produced more taller plant, more higher number of leaves and branches than control. Soil compaction significantly reduced the number of pods, roots, and fresh root weight compared to control. Bulk density (2.04 Mgm-3) required a significantly higher force (42.47 N) and energy (45.73 J) in harvesting than control and other compaction levels. Soil loss due to the groundnut harvesting increased (13- 42%) in all compaction levels although statistically not different. Soil compaction beyond 1.88 Mg m-3 could affect the growth and the yield of groundnut and could increase the soil loss at harvesting.

Relationship between compaction levels (bulk density) and chemical properties of different textured soil

The investigation entitled “Study of relationship between compaction level (bulk density) and chemical properties of different textured soil” was carried out using various research materials and analytical techniques during 2017-18 at department laboratory of Soil Science at Sardar Vallabhbhai Patel University of Agriculture and Technology, Meerut, UP, India. Results of study reveals that levels of compaction does not affects pH and EC significantly however soil OC was affected significantly. More impact was found in organic carbon as compare to pH and EC. Effect of compaction on amount of OC in different textured soil indicates that more organic carbon was found in sandy clay loam soil followed by sandy loam and minimum in loamy sand at same degree of compaction. A strong negative correlation of bulk density with pH (r = - 0.912, -0.943 and -0.943) EC (r = - 0.988, -0.991 and -0.992) and OC% (r = - 0.993, -0.985 and -0.989) for loamy sand, sandy loam and sandy clay loam soil, respectively was observed. The available macro nutrients (N, P and K) of soil decreased significantly with an increase in the level of compaction. A strong negative correlation of bulk density with available N (r = - 0.993, -0.995 and -0.992), available P (r = -0.985, -0.983 and -0.980) and available K (r = -0.925, -0.979 and -0.984) for loamy sand, sandy loam and sandy clay loam soil, respectively was found. Unlike available macro nutrient, the micro nutrient of soil also decreased with an increase in the level of compaction. A strong negative correlation between bulk density and available micronutrients Zinc r = - 0.925, -0.944 and -0.929 and Iron r = -0.981, -0.974 and -0.931 for loamy sand, sandy loam and sandy clay loam soil, respectively was also recorded.

Evaluating Soil–Root Interaction of Hybrid Larch Seedlings Planted under Soil Compaction and Nitrogen Loading

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.