Depth Of Soil Layer Research Articles

Liming and phosphate fertilization influence soil fertility, physical properties, and carbon stock in a subtropical Ferralsol in Brazil

Understanding the effects of liming plus phosphate fertilization on soil physical and chemical properties, as well as carbon stock, is critical for improving soil fertility management under conventional till (CT) and no-till (NT) systems. This study aimed to quantify changes in these soil properties resulting from incorporation (CT) or not (NT) of limestone and phosphorus (P) in a subtropical Ferralsol in southern Brazil. The experiment was conducted in Campo Mourão, Paraná State, Brazil, according to a randomized complete block design with a 6 × 4 factorial arrangement and four replications. The treatments comprised six strategies for limestone and P management and four soil depth layers (0–0.05, 0.05–0.10, 0.10–0.20 and 0.20–0.40 m), as follows: NLNT - no liming under no-till; NLCT - no liming under conventional till; LPNT - liming and P fertilization under no-till; LPCT - liming and P fertilization under conventional till; LNT - liming under no-till; and LCT - liming under conventional till. In 2012, 5.0 Mg ha−1 dolomitic limestone and 53.3 kg ha−1 P were applied. In 2016, dolomitic limestone was reapplied to a soybean–wheat rotation. Liming and liming plus P treatments influenced soil properties up to a depth of 0.10 m, increasing pH and decreasing Al3+, without significant differences between CT and NT. Higher levels of Ca2+ and Mg2+ were observed at 0–0.05 m, except in unlimed treatments. Liming and liming plus P fertilization treatments resulted in mean increments of 1.83 and 1.37 cmolc dm−3 in Ca2+ and Mg2+ levels, respectively, regardless of the tillage system. Base saturation did not differ between treatments in the 0.10 m layer. However, LPCT resulted in higher base saturation in the 0.10–0.20 m (55 %) and 0.20–0.40 m (53 %) layers. P contents were affected up to 0.10 m depth, being 30 % higher in LPNT than in LPCT at 0–0.05 m. In the 0–0.05 m layer, soil bulk density was highest in NLCT and LPCT, and macroporosity was lowest in LPCT. Carbon stock was not affected by tillage practices, liming, or P fertilization. There was a positive correlation between P content and carbon stock at 0.20–0.40 m, suggesting that increased P availability at depth contributes to carbon sequestration. At 0–0.05 m, soil physical properties were negatively influenced by the combined application of liming and P fertilization under CT, indicating possible simultaneous effects on clay dispersion and pore obstruction.

Assessing and Quantifying the Carbon, Nitrogen, and Enzyme Dynamics Effects of Inter-row Cover Cropping on Soils and Apple Tree Development in Orchards

Cover crops between rows in orchards can improve the development of soil resources and increase agricultural productivity. However, there have been few reports of cover crops that can act as a “green manure” in apple orchards across arid and semiarid zones. This study investigated the effects of planting interrow vegetation on soil properties and apple tree performance during a 32-month experiment. There were six treatments: clean cultivation as a control; natural grass planting; planting with ryegrass; planting with alfalfa; planting with tall fescue; and planting with villous wild pea cover crops. The treatments primarily affected the 0- to 20-cm surface soil layer. Soil carbon, nitrogen, and enzyme levels initially decreased (during the first 12–24 months); then, they increased (24–32 months). The cover crops significantly increased nutrient contents (soluble organic carbon, microbial carbon and nitrogen, alkaline dissolved nitrogen, nitrate nitrogen, and ammonium nitrogen) in the 0- to 20-cm soil layer by more than 19.6% and increased the related enzyme activities by more than 25.2%. The alfalfa and wild pea alleys had a stronger effect on the soil environment than the control, natural grass, ryegrass, and tall fescue alley treatments; however, after 32 months, the alfalfa treatment inhibited fruit tree growth and development. This was unexpected because alfalfa seemed to have a positive effect on soil fertility characteristics. Under local ecological conditions, villous wild pea had the greatest effect on apple orchard productivity and significantly increased short branching by 15.9%, fruit weight per fruit by 12.6%, yield per plant by 8.6%, and soluble sugar content by 10.5% compared with clean cultivation. The correlation analysis showed that there were significant or highly significant positive correlations between fruit tree performance and soil carbon, nitrogen, and enzyme activity levels as the soil layer depth increased. Therefore, under local ecological conditions, cover crops have a greater effect on orchard surface soil fertility than on deeper soils, and intercropping with villous wild pea potentially produces the greatest improvement in apple orchard productivity.

The microbiome structure and shifts in surface and subsurface soil horizon of Haplic Luvisol under different crops cultivation

The presented study investigated the comparative approach to evaluate prokaryotic and fungal soil communities in association with various plant crops along the genetic soil horizon using a high-throughput sequencing technique, with special emphasis on subsoils. We evaluate the diversity, abundance and structure of soil microbiome through the depth profiles in Haplic Luvisol (Cutanic) soil collected from lucerne, pear orchard, vineyard, and wheat crop. The structure of soil microbial communities differed due to crop type as well as depth of soil layer. Additionally, some basic physicochemical properties (e.g. total organic carbon - TOC, total nitrogen - TN, dissolved organic carbon - DOC, dissolved nitrogen – DN, pH, clay content) as well as mass and morphological parameters of the plant roots were determined. The highest clay content was noted in illuvial (Bt) horizons (in all profiles). The content of the studied C and N forms was the highest in the Ap horizon and in some subsurface layers and generally decreased with depth. Generally, the highest TOC, TN and DOC content was noted in the orchard profile, while the lowest occurred in the vineyard profile. The opposite trend was found for available Mg content. In turn, the highest DN was determined in the winter wheat profile. Overall, the decrease of the abundances of the most dominant phyla with depth was observed. Using a holistic approach via microbiome investigation of bacterial and fungal communities along soil horizon in a long-term land use with different plant cultivation, we showed that land management not only affect α-diversity but also shift the structure and the composition of bacterial and fungal communities in response to land use, in particular we identified the highest values of biodiversity indicators were found under lucerne and the lowest under vineyard. Future work needs to include the importance of soil type in shaping soil microbial communities under the same land use and plant cultivation, especially under subsurface soil layers.

How does intercropping contribute to soil organic carbon accumulation? A global synthesis

Soil organic carbon (SOC) is the largest terrestrial carbon pool that can provide nutrients to plants. Intercropping is a sustainable agriculture method with appreciable potential to improve crop productivity and enhance SOC pools and mitigate soil degradation. However, the inconsistent findings generated by on-site experiments necessitate a comprehensive assessment of how intercropping affects SOC. To address this gap, we conducted a meta-analysis to assess the effect of intercropping on SOC. The data was collected through Web of Science, Scopus, and China National Knowledge Infrastructure (CNKI). The results showed that the SOC content of intercropping was 17.75 % higher than that of monocropping. The crop composition and depth of the soil layer were identified as the main factors affecting the accumulation of SOC. Further, the presence of legume crops is not necessary to promote SOC accumulation, and intercropping contributes to SOC accumulation in the 0–20 cm soil layer. Soil total nitrogen (TN), soil microbial carbon (MBC), soil microbial nitrogen (MBN), and the soil carbon/nitrogen (C/N) ratio are positively correlated with SOC accumulation, while soil microbial diversity and enzyme activity are negatively correlated with SOC accumulation. The advantage of SOC accumulation in intercropping is lost when the soil C/N ratio is higher than 10.79 compared to monocropping, and intercropping has a higher potential for SOC accumulation when the MBC is higher than 182.92 mg·kg–1. The SOC accumulation potential of intercropping is greater than that of monocropping when soil bacterial diversity is greater than 6.55. Thus, SOC accumulation in intercropping is affected by crop composition and depth of soil layer, and regulated by soil C/N ratio and microorganisms, especially in soil with low N or low C/N ratio.

Response of Soil Moisture to Four Rainfall Regimes and Tillage Measures under Natural Rainfall in Red Soil Region, Southern China

Investigating the effects of natural rainfall on the soil moisture for sloping farmland is extremely important for comprehending a variety of hydrological processes. Rainfall regimes can elicit different responses to soil moisture at the depth of soil layers, and the responses may differ depending on the landscape position of the sloping farmland. This paper utilized the surface runoff natural rainfall and soil moisture measured on sloping farmland with conventional tillage and contour tillage in the red soil area of China to investigate the influence of natural rainfall events on soil moisture content and to evaluate if the response results were consistent across the four rainfall regimes. Natural rainfall events were classified into different four regimes in line with rainfall duration, rainfall amount, and the maximum 30 min rainfall intensity (I30) by the k-means clustering method, including advanced, intermediate, uniform and delayed regimes. The result showed that the advanced regime was the predominant one in the study area, which represented 45.9% of the total rainfall events. The rainfall regimes influenced the surface runoff coefficient and runoff depth on sloping farmland for conventional and contour tillage, with the uniform regime generating the highest runoff coefficient (5.20% and 5.82%) and runoff depth (2.00% and 2.05%), respectively. For the conventional tillage, soil moisture at a depth of 0–20 cm increased appreciably when the rainfall amount was larger than 20 mm and larger than 30 mm for the advanced regime. For the contour tillage, soil moisture in 20–40 cm layer increased for the advanced regime when the rainfall amount was larger than 15 mm and 30 mm, while the values were modified with rainfall duration and the antecedent dry day (ADD). A longer rainfall duration had a more obvious effect on soil moisture increasing in deep soil. At a depth of 20 cm, the ADD showed an appreciably positive correlation with the increment in soil moisture, which means that a brief ADD produces a compounding effect for a natural rainfall event. The present results underline the complexity of the effect of the rainfall events on soil moisture under two tillage measures for different rainfall regimes and suggest that the advanced regime significantly affects the distinction of soil moisture and the contour tillage can effectively reduce soil water loss and enhance water storage on the sloping farmland with red soil, presenting a theoretical basis for local soil and water conservation research and sloping farmland conservation tillage management.

Long‐term effects of meadow management on seed bank diversity and composition

AbstractAimsOligotrophic grasslands are habitats that host among the most diverse plant communities in Europe. Altering management regimes by either intensifying or ceasing management is known to decrease plant diversity. Yet, despite its importance for the recovery of plant communities after disturbances, little is known about whether seed banks are also affected by changes in management. Here, we investigate the effect of management practices on a meadow seed bank using a long‐term manipulative experiment. We focus on the response of the seed bank to the treatments, and the relationship between the seed bank and the vegetation response.MethodsThe study was conducted in a species‐rich wet meadow. The experiment consists of a factorial combination of fertilization, mowing, and removal of the dominant species. After 20 years of management, the seed bank was sampled seasonally at two soil layer depths. Standing vegetation was recorded in June at the peak of vegetation.ResultsAll seed bank characteristics varied between soil layers. Mowing decreased seed density and diversity, while fertilization significantly affected the species composition. Dominant removal had no effect on the seed bank. While seed bank diversity was not correlated to vegetation diversity, individual species' responses to mowing and fertilization were positively correlated in the seed bank and the vegetation.ConclusionsOur results show that long‐term management influences the seed bank down to 10 cm of soil depth. Whereas mowing apparently reduced seed density and diversity, the effects of fertilization on these characteristics were harder to interpret. After 20 years, most species had concordant responses to both mowing and fertilization, indicating a low legacy of previous management regimes on the seed bank. Our study reveals that the intensification of grassland management has a profound effect on plant diversity by directly affecting plant communities and their seed‐bank‐driven recovery potential.

How Does Irrigation with Wastewater Affect the Physical Soil Properties and the Root Growth of Sugarcane under Subsurface Drip?

Studies on the development of the root system can provide important information about responses to different management strategies, such as the use of lower quality water, also evaluating the interaction between plants and the physical properties of the soil. This study tested the hypothesis that irrigation with treated sewage effluent (TSE) supplies the water needs of sugarcane plants, increasing root growth and improving the physical properties of the soil. We evaluated the effects of subsurface dripping with TSE or surface reservoir water (SRW) on the root development of first ratoon cane (Saccharum officinarum L.) and the physical properties of dystrophic red latosol. Irrigation treatments were applied at 20 and 40 cm and soil properties were evaluated at soil depth layers of 0–20, 20–40, 40–60, and 60–80 cm. We verified that under irrigation with TSE and SRW, shallower soil layers present better porosity, soil aggregation, and aggregate stability conditions, parameters that improve the root system development and plant growth. On the other hand, deeper soil layers have lower macroporosity and higher total clay volume, indicating the possibility of compaction and greater limitations for sugarcane root growth. These results are important for understanding soil quality and provide significant information for agricultural management and for the implementation of sustainable soil conservation practices. This study shows the efficiency of TSE as an alternative water source for sugarcane crops.

Influence of the Seabed Site and Island Structure on Seismic Response of Marine Artificial Islands

Compared with the marine structures such as sea-crossing bridges and offshore wind turbines, the marine artificial islands are bottom sitting structures and particularly sensitive to site conditions. Therefore, the study focuses on determining the effect of seabed site conditions and construction methods on the seismic performance of marine artificial islands. A seismic wave analysis model of seabed-seawater layer–artificial island coupling is developed by combining the self-programmed fluctuation analysis program and the dynamic analysis software. Firstly, the seismic response of marine artificial islands with different site conditions are analyzed by inputting P and SV waves. On that basis, the effects of incidence angles on the seismic response are explored. Then the study further explores the effects of different backfill materials and protective structures on the seismic response of the artificial island. Numerical results show that the silty soft soil layer can amplify the seismic response of seabed sites, and this amplification effect increases with the increase of the depth of silty soft soil layers. Moreover, the coral sand as backfill material can reduce the seismic response of marine artificial islands. The seismic response of marine artificial islands can also be reduced in the model with a protection structure. These results will provide some theoretical references for the site selection and construction method of marine artificial islands.

Research on mining-induced surface soil cracking mechanism and development depth of downward fracture

In order to reveal the cracking mechanism of surface soil layer caused by coal seam mining, and explore theoretical methods for predicting the development depth of downward fractures during mining. Based on the background of the No. 1–2 upper coal seam mining in Daliuta Coal Mine, combining with fracture mechanics, soil mechanics, physical similarity simulation and numerical calculation methods. The mining-induced cracking mechanism and criterion of surface soil layer were analyzed, the crack development pattern and expansion mechanism were revealed, and the prediction formula of downward crack development depth of surface soil layer was put forward. The research results show that surface cracks mainly occur in the tensile zone, the concentrated tensile stress produced by the subsidence of overburden in the tensile zone can lead to soil cracking. When the surface maximum horizontal tensile deformation exceeds the limit horizontal deformation of soil, the soil layer cracks, and the cracking criterion of the surface soil layer was given accordingly. The soil crack of coal seam mining belongs to the mixed mode crack, and the soil cracks tip starts cracking and expanding along the direction of the maximum principal stress, therefore, the initiation crack angle of soil crack tip was obtained, and the fracture criterion of soil crack was proposed. With the crack propagation and development, the microcosmic crack becomes the macroscopic downward fracture. When the horizontal stress of the soil decreases to the cohesive force of the soil, the downward fracture stops develop, and the calculation formula for the development depth of mining-induced downward fracture was proposed. The development and evolution law of downward fracture was revealed, after the surface cracks, with the advance of the longwall face, the downward crack continues to extend and develop to the deep. Downward fracture develops on the ground surface at the open cut side, the mined-out area and in front of the longwall face, the maximum development depth of downward fracture tends to be stable when the longwall face advances to a certain distance. According to the physical simulation, numerical calculation and theoretical calculation, the development depth of downward fracture in No 1–2 upper coal seam mining is 8.11 m, 8.21 m and 8.14 m respectively. The theoretical prediction formula is reliable, and the results can provide a new method for the research of the development depth of mining-induced surface downward fracture.

Determining The Depth of Hard Soil Layers Using Geoelectric Resistivity and Cone Penetration Test Methods (Case Study: Kelurahan Bontoramba Kecamatan Somba Opu Kabupaten Gowa)

Hard soil layers can impact the loading, stability, and behavior of structures in the geotechnical field. Comprehensive understanding of the depth and properties of hard soil layers can aid in designing suitable structures. Therefore, this study employed the resistivity geoelectric and Cone Penetration Test (CPT) methods to map the features of hard soil layers. Resistivity data were acquired through measurements utilizing the geoelectric method, while data on cone resistance, shear resistance, and friction ratio were gathered through field measurements using the CPT tool. The collected data was analyzed comprehensively to obtain a complete understanding of soil conditions. Based on resistivity values, the results indicated the research site comprises alluvium, very dry clay, and dry sandy soil. Based on the CPT test, it is determined that the layers contain mixtures of fine-grained soils, clay, silt, and sand. Therefore, it can be inferred that the dense sand lithology constitutes the hard soil layer geologically. The employment of both approaches delivers supplementary details on soil features and depth.

Soil Contamination and Ecological Risk Assessment of Different Types of Lithuanian Shooting Ranges

ABSTRACT Contamination at shooting ranges is a growing concern due to the accumulation of potentially toxic elements in the soil. The aim of the study was to determine the level of soil contamination in different types of Lithuanian shooting ranges (clay-target, practical, small-bore) and assess the potential ecological risks. Soil samples were taken in two soil layer depths (0–10 cm and 10–30 cm) and locations (range floor and berm/target line) of different types of shooting ranges. The soils of the practical and small-bore shooting ranges were neutral, clay target – slightly alkaline. The soil of the clay-target firing range floor had a significantly lower organic matter, than small-bore and practical firing ranges. Lead contamination was significantly higher in the floor and berm surface soil and subsoil (about 1000 mg kg−1 and 360–527 mg kg−1, respectively) of the practice range compared to the others and controls. The Cd concentrations in the surface soil of the practical range and the small-bore firing ranges and in the soil of the berm were considerably higher than in the soil of the clay target. There was a significant negative correlation between soil pH and Pb and Cd concentrations. Pb content was positively correlated with organic matter content. The soils of the practical range floor and berm indicated high ecological risk. The research showed that heavy metal contamination is specific in different types of shooting ranges, therefore various management practices should be applied to prevent pollution in particular shooting range.

Variations in soil physico-chemical properties, soil stocks, and soil stoichiometry under different soil layers, the major forest region Liupan Mountains of Northwest China.

Liupan Mountains are an important region in China in the context of forest cover and vegetation due to huge afforestation and plantation practices, which brought changes in soil physio-chemical properties, soil stocks, and soil stoichiometries are rarely been understood. The study aims to explore the distribution of soil nutrients at 1-m soil depth in the plantation forest region. The soil samples at five depth increments (0-20, 20-40, 40-60, 60-80, and 80-100 cm) were collected and analyzed for different soil physio-chemical characteristics. The results showed a significant variation in soil bulk density (BD), soil porosity, pH, cation exchange capacity (CEC), and electric conductivity (EC) values. More soil BD (1.41 g cm-3) and pH (6.97) were noticed in the deep soil layer (80-100 cm), while the highest values of porosity (60.6%), EC (0.09 mS cm-1), and CEC (32.9 c mol kg-1) were reflected in the uppermost soil layer (0-20 cm). Similarly, the highest contents of soil organic carbon (SOC), total phosphorus (TP), available phosphorus (AP), total nitrogen (TN), and available potassium (AK) were calculated in the surface soil layer (0-20 cm). With increasing soil depth increment a decreasing trend in the SOC and other nutrient concentration were found, whereas the soil total potassium (TK) produced a negative correlation with soil layer depth. The entire results produced the distribution of SOCs and TNs (stocks) at various soil depths in forestland patterns were 0→20cm > 20→40cm > 40→60cm ≥ 60→80cm ≥ 80→100 cm. Furthermore, the stoichiometric ratios of C, N, and P, the C/P, and N/P ratios showed maximum values (66.49 and 5.46) in 0-20 cm and lowest values (23.78 and 1.91) in 80-100 cm soil layer depth. Though the C/N ratio was statistically similar across the whole soil profile (0-100 cm). These results highlighted that the soil depth increments might largely be attributed to fluctuations in soil physio-chemical properties, soil stocks, and soil stoichiometries. Further study is needed to draw more conclusions on nutrient dynamics, soil stocks, and soil stoichiometry in these forests.

Development of Nonlinear Site Amplification Model Based on Average Shear-wave Velocity of Soil Layer and Bedrock Depth

Development of Nonlinear Site Amplification Model Based on Average Shear-wave Velocity of Soil Layer and Bedrock Depth

Hydrothermal Conditions in Deep Soil Layer Regulate the Interannual Change in Gross Primary Productivity in the Qilian Mountains Area, China

The variability in soil hydrothermal conditions generally contributes to the diverse distribution of vegetation cover types and growth characteristics. Previous research primarily focused on soil moisture alone or the average values of soil hydrothermal conditions in the crop root zone (0–100 cm). However, it is still unclear whether changes in gross primary productivity (GPP) depend on the hydrothermal conditions at different depths of soil layers within the root zone. In this study, the soil hydrothermal conditions from three different layers, surface layer 0–7 cm (Level 1, L1), shallow layer 7–28 cm (Level 2, L2), and deep layer 28–100 cm (Level 3, L3) in the Qilian Mountains area, northwestern China, are obtained based on ERA5-Land reanalysis data. The Sen-MK trend test, Pearson correlation analysis, and machine learning algorithm were used to explore the influence of these three soil hydrothermal layers on GPP. The results show that soil moisture values increase with soil depth, while the soil temperature values do not exhibit a stratified pattern. Furthermore, the strong correlation between GPP and deep soil hydrothermal conditions was proved, particularly in terms of soil moisture. The Random Forest feature importance extraction revealed that deep soil moisture (SM-L3) and surface soil temperature (ST-L1) are the most influential variables. It suggests that regulations of soil hydrothermal conditions on GPP may involve both linear and nonlinear effects. This study can obtain the temporal and spatial dynamics of soil hydrothermal conditions across different soil layers and explore their regulations on GPP, providing a basis for clarifying the relationship between soil and vegetation in arid mountain systems.

How geoecological components of a terroir can be altered by spatial changes of vineyards – A case study from Eger Wine District (Hungary)

Terroir is a concept referring interactions of natural (topography, lithology, climate, soil etc.) and human (economic conditions, traditions, cultivation practices, etc.) factors; therefore, terroir is spatially delimited and subjected to environmental, socio-economic, and temporal changes. The geoecological background of wine districts are considered more stable among them, but, because of its natural diversity and the spatial changes of production sites, changes in abiotic terroir components might occur too. In this study the spatial changes of grape production sites in Eger Wine District (Hungary) across two and a half centuries (1784 to 2018), and their consequences on the composition of the geoecological factors (lithology, topography, soil characteristics) were analyzed. Modernization of cultivation, urbanization and increase of built-up areas around the central settlement resulted in decreased concentration, i.e. increased spatial dispersion to more remote vineyards further from Eger. It also has consequences on the lithological and topographical composition of the production sites. Besides the slightly increasing extent of vineyards (from 5346 ha to 7413 ha) we found a distinct decrease of vineyards at higher elevations and a substantial increase at lower elevations. Distribution according to slope gradient changed also remarkably, with the share of vineyards on <5 % slopes from 38 % to 65 %. These changes resulted in transformations of pedological characteristics according to the comparison of vineyard’s extent with soil map data: vineyards shifted to slightly acidic, more fertile (i.e. deeper soil layer with higher organic carbon content) soils. The share of vineyards with different lithology and parent material also changed: loose, calcareous Tertiary sediments decreased almost to half, and the share of vineyards over acidic volcanics and their weathered regoliths almost doubled. Comparing these two dominant lithological types and soil profiles derived from them, different pedological characters and taxonomic status were found (Phaeozems and Vertisols). However, comparison of these two lithological types based on main topsoil characteristics (pH, SOC, carbonates, depth of fertile soil layer, N, P, K content) according to 25 randomly chosen surficial soil samples at production sites, showed no significant differences.. In the case of this particular wine district, spatial changes of the production sites affected mostly the distribution by elevation, by slope gradient, but did not alter significantly the surface soil character of the terroir.

Uncertainty estimation for a new exponential-filter-based long-term root-zone soil moisture dataset from Copernicus Climate Change Service (C3S) surface observations

Abstract. Soil moisture is a key variable in monitoring climate and an important component of the hydrological, carbon, and energy cycles. Satellite products ameliorate the sparsity of field measurements but are inherently limited to observing the near-surface layer, while water available in the unobserved root-zone controls critical processes like plant water uptake and evapotranspiration. A variety of approaches exist for modelling root-zone soil moisture (RZSM), including approximating it from surface layer observations. While the number of available RZSM datasets is growing, they usually do not contain estimates of their uncertainty. In this paper we derive a long-term RZSM dataset (2002–2020) from the Copernicus Climate Change Service (C3S) surface soil moisture (SSM) COMBINED product via the exponential filter (EF) method. We identify the optimal value of the method's model parameter T, which controls the level of smoothing and delaying applied to the surface observations, by maximizing the correlation of RZSM estimates with field measurements from the International Soil Moisture Network (ISMN). Optimized T-parameter values were calculated for four soil depth layers (0–10, 10–40, 40–100, and 100–200 cm) and used to calculate a global RZSM dataset. The quality of this dataset is then globally evaluated against RZSM estimates of the ERA5-Land reanalysis. Results of the product comparison show satisfactory skill in all four layers, with the median Pearson correlation ranging from 0.54 in the topmost to 0.28 in the deepest soil layer. Temporally dynamic product uncertainties for each of the RZSM product layers are estimated by applying standard uncertainty propagation to SSM input data and by estimating structural uncertainties in the EF method from ISMN ground reference measurements taken at the surface and at varying depths. Uncertainty estimates were found to exhibit both realistic absolute magnitudes and temporal variations. The product described here is, to the best of our knowledge, the first global, long-term, uncertainty-characterized, and purely observation-based product for RZSM estimates up to 2 m depth.

Analisis Struktur Lapisan Tanah Menggunakan Metode Geolistrik Resistivitas Konfigurasi Schlumberger Vertikal di Kompleks Perumahan Dosen Uncen Kali Acai, Kulurahan VIM, Distrik Abepura, Kota Jayapura

Research on the analysis of the structure of the soil layer using the Vertical Schlumberger Geoelectric method in the Lecturer Housing Complex of Uncen Kali Acai, VIM Village, Abepura District, Jayapura City. This study aims to determine the soil layer, determine the location and depth of the soft soil layer, determine the soft and hard soil. Data retrieval using geoelectric resistivity method with vertical Schlumberger configuration. The instrument used for subsurface surveys is the HV 500 AK resistivity meter. Field measurements obtained electric current and voltage values and then calculated the apparent resistivity values obtained from analysis using IP2win software to see the distribution profile, depth, and thickness of the soil layer.After doing research in the field, it can be seen that the subsurface structure at the research site is dominated by soft clay material with a resistivity value of 0.24 -692.00 Ωm. . In addition, there is a layer of hard rock in the form of a mixture of limestone with a resistivity value of 1181.00 - 8319.00 Ωm.. And the types of subsurface rocks found at the research site are clay, sandstone and limestone.

Field study on installation effects of pre-bored grouted planted pile in deep clayey soil

This paper presents the results of field tests performed to investigate the installation effects of pre-bored grouted planted (PGP) pile in deep clayey soil. The variation of horizontal soil displacements, excess pore water pressures and lateral soil pressures was measured in the PGP pile installation process. The test results show that the drilling and grouting process induced large horizontal soil displacements in the soil within a radial distance of 2 d ( d is pile diameter), and the maximum horizontal soil displacements induced by the drilling and grouting process were smaller than 15.9 mm when the radial distance reached 4–5 d. Moreover, the horizontal soil displacements decreased along the soil layer depth, as the superficial soil layers were of small deformation modulus and lateral soil pressure. The drilling process brought large excess pore water pressures in the soil when the radial distance was less than 3 d, and the excess pore water pressures induced by the drilling stage were all less than 55 kPa when the radial distance reached 4–6 d. The drilling process also induced some lateral soil pressure increases in the soil within a radial distance of 3 d, while the measured maximum lateral soil pressure increases were smaller than 10.9 kPa when the radial distance increased to 4 d. On the whole, the excess pore water pressures and lateral soil pressure increases induced by the installation of PGP pile were much smaller than that induced by the installation of driven PHC pile. Moreover, the horizontal soil displacements, excess pore water pressures and lateral soil pressure increases induced by the installation of PGP pile all recovered rapidly after the installation of pile, as the cemented soil in the pile hole was in liquid state after the drilling and grouting stage.

Using surface soil layer depth for determining soil quality index for evaluating productivity of potato (Solanum tuberosum L.) in Hokkaido, Japan

ABSTRACT A comprehensive quantification of soil quality is necessary for data-driven soil management, and numerous studies have sought to devise methods for determining the soil quality index (SQI) to assess soil productivity. However, most studies have focused on topsoil properties rather than deeper soil properties. Therefore, this study attempted to calculate the SQI by incorporating subsoil properties and surface soil layer depth and topsoil properties, targeting farms cultivating potatoes in Tokachi region, Hokkaido. The soil parent material in this region is primarily composed of a mixture of alluvial deposits, volcanic ash, and peat, which makes the comparison between the various soil properties difficult for evaluation by farmers. Principal component analysis (PCA) and regression analysis were used to select the minimum data set (MDS) representing the variance of the original data set: exchangeable Ca, K, pH, solid phase, and acid-soluble Cu in descending order of weight. Weights were allocated based on the eigenvalues of the principal components. This study selected MDS’s parameters from properties with soil diagnosis criteria based on past research on productivity evaluation. The selected parameters contained both physical and chemical properties, which indicated that the soil quality was evaluated from both aspects. For surface soil layer depth consideration, the corrected SQI was calculated by reducing more when the depth was shallower. SQI considering subsoil properties did not correlate with yield (r = 0.358), but SQI considering surface soil layer depth was significant (r = 0.515–0.518) regardless of the soil type (parent material) and cultivar. Correlations between SQI considering depth and yield were stronger when considering a single cultivar with the greatest number of sites (r = 0.620–0.641). A deeper surface soil layer depth would provide more macropores to plant roots and improve the availability of air, greatly affecting soil quality in the Tokachi region, where precipitation is high during the growth season. Therefore, this study reveals the importance of considering the surface soil layer depth to evaluate soil productivity using the SQI.

Phenotypic quantification of root spatial distribution along circumferential direction for field paddy-wheat.

Plant roots are essential for water and nutrient absorption, anchoring, mechanical support, metabolite storage and interaction with the surrounding soil environment. A comprehensive understanding of root traits provides an opportunity to build ideal roots architectural system that provides improved stability and yield advantage in adverse target environments caused by soil quality degradation, climate change, etc. However, we hypothesize that quantitative indicators characterizing root system are still need to be supplemented. Features describing root growth and distribution, until now, belong mostly to 2D indicators or reflect changes in the root system with a depth of soil layers but are rarely considered in a spatial region along the circumferential direction. We proposed five new indicators to quantify the dynamics of the root system architecture (RSA) along its eight-part circumferential orientations with visualization technology which consists of in-situ field root samplings, RSA digitization, and reconstruction according to previous research based on field experiments that conducted on paddy-wheat cultivation land with three fertilization rates. The experimental results showed that the growth space of paddy-wheat root is mainly restricted to a cylinder with a diameter of 180 mm and height of 200 mm at the seedlings stage. There were slow fluctuating trends in growth by the mean values of five new indicators within a single volume of soil. The fluctuation of five new indicators was indicated in each sampling time, which decreased gradually with time. Furthermore, treatment of N70 and N130 could similarly impact root spatial heterogeneity. Therefore, we concluded that the five new indicators could quantify the spatial dynamics of the root system of paddy-wheat at the seedling stage of cultivation. It is of great significance to the comprehensive quantification of crop roots in targeted breeding programs and the methods innovation of field crop root research.