Soil Content Research Articles

Effect of intercropping and biochar amendments on lead removal capacity by Corchorus olitorius and Zea mays.

Intercropping is a sustainable strategy recognized for boosting crop production and mitigating heavy metal toxicity in contaminated soils. This study investigates the effects of biochar amendments on Pb-contaminated soil, utilizing monocropping and intercropping techniques with C. olitorius and Z. mays. The research assesses Pb removal capacity, nutrient uptake, antioxidant enzymes, and soil Pb fractionation. In monocropping, the phytoremediation ratio for C. olitorius increased from 16.67 to 27.33%, while in intercropping, it rose from 19.00 to 28.33% with biochar amendments. Similarly, Z. mays exhibited an increased phytoremediation ratio from 53.33 to 74.67% in monocropping and from 63.00 to 78.67% in intercropping with biochar amendments. Intercropping significantly increased the peroxidase (POD) activity in Z. mays roots by 22.53%, and there were notable increases in shoot POD of C. olitorius (11.54%) and Z. mays (16.20%) with biochar application. CAT showed consistent improvements, increasing by 37.52% in C. olitorius roots and 74.49% in Z. mays roots with biochar. Biochar amendments significantly increased N content in soil under sole cropping of Z. mays and intercropping systems. In contrast, Cu content increased by 56.34%, 59.05%, and 79.80% in monocropping (C. olitorius and Z. mays) and intercropping systems, respectively. This suggests that biochar enhances nutrient availability, improving phytoremediation efficacy in Pb-contaminated soil. Phyto availability of trace metals (Zn, Mn, Cu, and Fe) exhibited higher levels with biochar amendments than those without. The findings indicate that intercropping and biochar amendments elevate antioxidant enzyme levels, reducing reactive oxygen species and mitigating Pb toxicity effects. This approach improves phytoremediation efficiency and holds promise for soil pollution remediation while enhancing nutrient content and crop quality in Pb-contaminated soil.

ПОКАЗАТЕЛИ КАЧЕСТВА МОЛОКА И МОЛОЧНОЙ ПРОДУКТИВНОСТИ ПРИ ИСПОЛЬЗОВАНИИ ПРЕПАРАТА «ЙОДИНОЛ-ЯНТАРНЫЙ» В РАЦИОНЕ ЛАКТИРУЮЩИХ КОЗОМАТОК НУБИЙСКОЙ МЯСО-МОЛОЧНОЙ ПОРОДЫ

Proper nutrition is a prerequisite for normal physiological and mental development, as well as strengthening immunity to various adverse environmental factors. Goat milk products are especially relevant in baby food due to their unique properties. The reduced casein content in the fractional composition of proteins makes the products hypoallergenic, and the predominance of casein contributes to the rapid formation of a fine clot in the child's stomach. A high naive degree of fat dispersion facilitates and improves its assimilation, and also contributes to the assimilation of a large amount of polyunsaturated fatty acids that ensure the normal development and formation of the child's body. In addition, goat's milk contains a large amount of vitamins: A, C, B, PP, as well as trace elements: calcium, phosphorus, magnesium, cobalt. Providing children with high-quality balanced food is an important state task, the fulfillment of which is the key to the health of the nation. Since most regions of Russia are iodine deficient, they need the trace element iodine for life, which is why it is necessary to adjust the mineral composition of goat's milk. For the animals themselves, this is also relevant for the treatment and prevention of iodine deficiency. The influence of an energy-metabolic preparation based on iodine and succinic acid on the quality indicators of milk and milk productivity of lactating goats is considered. Literature data indicate an increase in the therapeutic effect when succinic acid is added to the active substance. In nature, there is a direct relationship between the iodine content in soil, water, plants and in the animal body. With insufficient intake of iodine with feed and water, the productivity, reproductive qualities, and genetic potential of animals decrease. Therefore, an urgent problem is to find ways to replenish iodine deficiency in the body of farm animals. In this regard, studies were conducted on the quality of milk of lactating goats of the Nubian meat and dairy breed when they were injected with a new drug "Iodinol-Yantarny". The effective effect of this drug on milk quality indicators in dairy goat breeding has been proven.

Rural integrated sanitation assessment at community level in Chongqing, China—A cluster analysis

Equitable access to sanitation for all is a goal of sustainable development, notably in rural areas. However, studies including economic, socio-cultural, and other factors that have been conducted to comprehensively assess rural sanitation at the community level in developing countries are limited. This study aimed to investigate the current state of rural environmental sanitation on the community level and to evaluate the characteristics of the diverse sub-clusters. A multidimensional environmental sanitation survey was conducted on 400 communities in Chongqing, China in 2020, and the priority options for improving sub-clusters’ sanitation were explored using cluster analysis. Among all communities, more than 60 % had positive village appearance, 50.50 % had domestic sewage treatment, and the coverage rate of household sanitary toilets was 72.28 %. The average content for lead, cadmium (Cd), and chromium in soil was 26.01, 0.53, and 54.47 mg/kg, respectively. The communities were clustered into 3 groups (I, II, III) based on similar characteristics including basic information, village appearance, water, sanitation, hygiene management, bio-vector control, and soil pollution. The proportion of cluster I, II, and III was 39.25 % (157/400), 31.75 % (127/400), and 29.00 % (116/400), respectively. Each cluster had its sanitation characteristics, and significant differences among the sub-clusters were observed in Cd of soil (p = 0.001), domestic sewage disposal ratio (p < 0.001), and environmental health funding (p = 0.001). To sum up, the environmental sanitation in rural areas of Chongqing was better than that of the national average in China, but the Cd content of farmland soil was higher. Our study provides novel evidence for assessing the characteristics of rural sanitation at the community level, and communities with similar environmental health status were clustered into the same group, while the heterogeneity of different sub-cluster was thoroughly characterized. The hierarchical control strategy should be performed in communities based on different characteristics and deficiencies of the clusters to improve environmental sanitation.

Study on the microstructure and strength characteristics of marine soft soil under wet-dry cycle condition

For marine soft soil under the periodic wave loading, the pore water content in soil suffering dry-wet cycle for a long time, which affects its microstructure and macroscopic mechanical strength, resulting in insufficient bearing capacity and excessive deformation of soft soil. To reveal the microstructural characteristics and strength attenuation law of marine soft soil under dry-wet cycle condition, electron microscopy scanning and direct shear tests under different times of dry-wet cycles were carried out, and the mathematical equations of pore structure and strength parameters were established based on fractal theory. The research results showed that: (1) The pore structure changed considerably after the first dry-wet cycle, and then changed gently with the increase of dry-wet cycle times, which was reflected by the fractal dimension D value decreases to a constant value gradually. (2) The shear strength of the soil diminishes with an increase in the number of dry-wet cycle times, and the maximum attenuation occurs after the first dry-wet cycle. (3) The relationship between cohesion (c), internal friction angle (φ), and fractal dimension (D) is exponential, with the curve shapes being concave and convex, respectively.

Effects of Four Amendments on Cadmium Bioavailability and Enzyme Activity in Purple Soil

In this study, the effects of four types of amendments on effective Cd and Cd content in different parts of prickly ash soil and soil enzyme activity were studied, which provided scientific basis for acidification improvement of purple soil and heavy metal pollution control. A field experiment was conducted. Six treatments were set up:no fertilizer (CK), only chemical fertilizer (F), lime + chemical fertilizer (SF), organic fertilizer + chemical fertilizer (OM), biochar + chemical fertilizer (BF), and vinasse biomass ash + chemical fertilizer (JZ). Soil pH; available Cd (DTPA-Cd); Cd content in branches, leaves, shells, and seeds of Zanthoxylum; as well as the activities of catalase (S-CAT), acid phosphatase (S-ACP), and urease (S-UE) in different treatments were studied, and their relationships were clarified. The results showed following:① The two treatments of vinasse biomass ash + chemical fertilizer and lime + chemical fertilizer significantly increased soil pH (P &lt; 0.05) to 3.39 and 2.25 units higher than that in the control, respectively. Compared with that in the control treatment, the content of available Cd in soil under vinasse biomass ash + chemical fertilizer and lime + chemical fertilizer treatment decreased by 28.91 % and 20.90 %, respectively. ② The contents of Cd in leaves, shells, and seeds of Zanthoxylum were decreased by 31.33 %, 30.24 %, and 34.01 %, respectively. The Cd enrichment ability of different parts of Zanthoxylum was different, with the specific performances being leaves &gt; branches &gt; seeds &gt; shells. Compared with that of the control, the enrichment coefficient of each part of Zanthoxylum treated with vinasse biomass ash + chemical fertilizer decreased significantly(P &lt; 0.05)by 27.54 %-40.0 %. ③ The changes in catalase and urease activities in soil treated with amendments were similar. Compared with those in the control group, the above two enzyme activities were significantly increased by 191.26 % and 199.50 %, respectively, whereas the acid phosphatase activities were decreased by 16.45 %. Correlation analysis showed that soil available Cd content was significantly negatively correlated with soil pH value(P &lt; 0.01), S-CAT and S-UE enzyme activities were significantly positively correlated with soil pH(P &lt; 0.01), and the soil available Cd content was significantly negatively correlated (P &lt; 0.01); the S-ACP enzyme showed the complete opposite trends. The application of lime and vinasse biomass ash to acidic purple soil had the most significant effect on neutralizing soil acidity. It was an effective measure to improve acidic purple soil and prevent heavy metal pollution by reducing the effective Cd content in soil and improving the soil environment while inhibiting the absorption and transfer of Cd in various parts of Zanthoxylum.

Effects of Waterlogging Stress on Root Growth and Soil Nutrient Loss of Winter Wheat at Seedling Stage

With global climate change, flooding events are becoming more frequent. However, the mechanism of how waterlogging stress affects crop roots needs to be studied in depth. Waterlogging stress can also lead to soil nitrogen and phosphorus loss, resulting in agricultural surface pollution. The aim of this study is to clarify the relationship between soil nitrogen and phosphorus distribution, root growth characteristics, and nitrogen and phosphorus loss in runoff water under waterlogging stress during the winter wheat seedling stage. In this paper, Zhengmai 136 was selected as the experimental material, and two water management methods (waterlogging treatment and non-waterlogging control treatment) were set up. Field experiments were conducted at the Wudaogou Hydrological Experimental Station in 2022 to assess the nitrogen and phosphorus concentrations in runoff water under waterlogging stress. The study also aimed to analyze the nitrogen and phosphorus content and the root distribution characteristics in different soil layers under waterlogging stress. The results showed as the following: 1. Waterlogging stress increased the characteristic parameters of winter wheat roots in both horizontal and vertical directions. Compared with the control treatment, the root length increased by 1.2–29.9% in the waterlogging treatment, while the root surface area and volume increased by an average of 3.1% and 41.9%, respectively. 2. Nitrogen and phosphorus contents in waterlogged soils were enriched in the 0–20 cm soil layer, but both tended to decrease in the 20–60 cm soil layer. Additionally, there was an inverse relationship between the distribution of soil nutrients and the distribution of wheat roots. 3. During the seedling stage of winter wheat, nitrogen loss was the main factor in the runoff water. In addition, nitrate nitrogen concentration averaged 55.2% of the total nitrogen concentration, while soluble phosphorus concentration averaged 79.1% of the total phosphorus concentration. 4. The results of redundancy analysis demonstrated that available phosphorus in the soil was the key environmental factor affecting the water quality of runoff water. Total phosphorus and dissolved phosphorus in the water were identified as the dominant factors influencing root growth.

Spatiotemporal Simulation of Soil Pb Accumulation Process in Urban-Rural Areas: A Case Study of a Large City in Central China

The high intensity of diverse human activities in urban-rural areas leads to complex soil Pb accumulation processes and high spatiotemporal heterogeneity, making it difficult to reveal the spatiotemporal characteristics of soil Pb accumulation in these areas. This study used a typical urban-rural area in a large city in Central China as the study area, constructed a soil Pb accumulation model, and established a spatiotemporal simulation method for soil Pb accumulation processes combining this model and land use classification and simulation results. Using this method, we simulated the soil Pb content in the study area from 2013 to 2040 and elucidated the future spatiotemporal variation characteristics of soil Pb content. The results showed that the average soil Pb content in the study area in 2013 was approximately 1.77 times the background value of the Pb content in the surface soil of the province where the city is located, indicating significant soil Pb pollution. The soil Pb content was predicted to continue increasing from 2013 to 2040, with relatively low increases (0.53-2.25 mg·kg-1) in the western, northern, and southern parts of the study area, accounting for 25.46 % of the total area, and relatively high increases (3.98-5.70 mg·kg-1) in the eastern part, accounting for 17.14 % of the total area. The increase in the area of forest land and the decrease in the area of water bodies and grassland in the eastern part of the study area led to a substantial rise in soil Pb content in this region; in addition, the spatial distribution of soil Pb content was highly correlated with the distribution of important factories and transportation facilities. This study overcomes the limitations of previous research that treated land use as unchanging and to a certain extent reflects the impact of regional land use changes on the heavy metal accumulation process. It provides a method for simulating the soil Pb accumulation process in urban-rural areas and a basis for controlling soil Pb pollution in the city's urban-rural areas.

Geochemical characteristics, source analysis, influencing factors, and reserves of soil Selenium in Wuming, Guangxi, China.

Although selenium (Se) reserves are crucial for the development and exploitation of Se-rich resources in karst soil areas, research on these reserves is still limited. A comprehensive study was conducted in a typical karst region known for its Se richness. A total of 12,547 surface soil samples, 134 deep soil samples, and 60 soil profiles from various locations were systematically collected. The findings showed that the Se content in the surface soil ranged from 0.073 to 9.04mg/kg, with a baseline level of 0.84mg/kg. This underscores the high background level and moderate variability in the region. Surface soil Se exhibited a notable positive correlation with deep soil Se, and an inverse correlation with pH (p < 0.01). One-way analysis of variance indicated that land formations and soil structure were the primary determinants affecting the concentration of Se in the topsoil (p = 0.000), with parent rock type and land-use type following closely (p = 0.003). In addition, the study included an investigation of soil Se variations with depth using 60 soil profiles. Through this analysis, it was revealed that Se content exhibited an exponential change with depth. Multiple integrations were employed to derive formulas for calculating Se reserves in the 0-200cm depth range. Following these calculations, the estimations of Se stockpile across diverse types of source materials, varieties of soils, and land management methods were determined, highlighting the findings using a passive construction. This paper lays the groundwork for advancing the extraction and application of Se.

Determination of Low Concentrations of Mercury Based on the Electrodeposition Time.

Soil plays a crucial role in human health through its impact on food and habitation. However, it often contains toxic heavy metals, with mercury being particularly hazardous when methylated. Currently, high-sensitivity, rapid detection of mercury is achievable only through electrochemical measurements. These measurements require pretreatment of the soil sample and the preparation of a calibration curve tailored to the sample's condition. In this study, we developed a method to determine the environmental standard value of mercury content in soil by significantly reducing the pretreatment process. Our approach involves analyzing current peaks from electrodeposition times using specific electrodes and solvent settings. This method demonstrates low error rates under low concentration conditions and can detect mercury levels as low as 0.5 ppb in soil leachate and reagent dilution series. This research facilitates the determination of low mercury concentrations in solutions containing various soil micro-compounds without the need for calibration curves.

Impact of Integrated Nutrient Management on Yield, Soil, and Plant Nutrient Status in Sweet Orange (Citrus sinensis L.) cv. Phule Mosambi

ABSTRACT Impact of integrated nutrient management on plant and soil nutrient status in sweet orange (Citrus sinensis L.) cv. Phule Mosambi was investigated for two consecutive years i.e. 2019 and 2020 at the Horticultural Research Farm, College of Horticulture, Anand Agricultural University, Anand. The experiment was laid out in completely randomized design (CRD) comprised of 11 treatments replicated thrice. Significantly higher yield was recorded with T11 [50% Recommended Dose of Nitrogen (RDN) + 20 kg farmyard manure (FYM)/tree +25% nitrogen (N) from Castor Cake + 10 ml Bio NPK Consortium + Micronutrient foliar spray (1% Grade IV)] (17.35 and 17.01 t/ha) which was at par with T10 (15.92 and 15.56 a t/ha) during 2019 and 2020, respectively. Amongst the treatments, T11 had increased the nutrient contents of soil as well as in plant and recorded maximum available nitrogen (N), available potassium (K), soil boron (B) content, plant nitrogen (N) content, plant iron (Fe) content, plant copper (Cu) content and plant boron (B) content in both the years whereas available phosphorous (P) was found higher in treatment T7 in both the years. Treatment T8 recorded highest soil copper (Cu) content in both the years. As far as plant zinc (Zn) content is concerned, it was found higher in treatment T9 in both the years.

The limited effect of deforestation on stabilized subsoil organic carbon in a subtropical catchment

Abstract. Predicting the quantity of soil organic carbon (SOC) requires understanding how different factors control the amount of SOC. Land use has a major influence on the function of the soil as a carbon sink, as shown by substantial organic carbon (OC) losses from the soil upon deforestation. However, predicting the degree to which land use change affects the OC content in soils and the depth down to which this occurs requires context-specific information related to, for example, climate, geochemistry, and land use history. In this study, 266 samples from forests and agricultural fields were collected from 94 soil profiles down to 300 cm depth in a subtropical region (Arvorezinha, southern Brazil) to study the impact of land use on the amount of stabilized OC along the soil profile. We found that the stabilized OC content was not affected by land use below a depth of 90 cm. Along the soil profile, the amount of stabilized OC was predominantly controlled by land use and depth in addition to the silt and clay content and aluminium ion concentrations. Below 100 cm, none of the soil profiles reached a concentration of stabilized OC above 50 % of the stabilized OC saturation point (i.e. the maximum OC concentration that can physically be stabilized in these soils). Based on these results, we argue that it is unlikely that deeper soil layers can serve as an OC sink over a timescale relevant to global climate change due to the limited OC input in these deeper layers. Furthermore, we found that the soil weathering degree was not a relevant control on the amount of stabilized OC in our profiles because of the high weathering degree of the studied soils. It is therefore suggested that, while the soil weathering degree might be an effective controlling factor of OC stabilization over a large spatial scale, it is not an informative measure for this process at regional and local scales (with similar climate, bedrock, and weathering history) in highly weathered soils.

Agricultural waste-based modified biochars differentially affected the soil properties, growth, and nutrient accumulation by maize (Zea mays L.) plants

Biochar (BC) is an organic compound formed by the pyrolysis of organic wastes. Application of BCs as soil amendments has many benefits including carbon sequestration, enhanced soil fertility and sustainable agriculture production. In the present study, we acidified the different BCs prepared from rice straw, rice husk, wheat straw, cotton stalk, poultry manure, sugarcane press mud and vegetable waste; following which, we applied them in a series of pot experiments. Comparisons were made between acidified and non- acidified BCs for their effects on seed germination, soil properties (EC, pH) nutrient contents (P, K, Na) and organic matter. The treatments comprised of a control, and all above-described BCs (acidified as well as non-acidified) applied to soil at the rate of 1% (w/w). The maize crop was selected as a test crop. The results showed that acidified poultry manure BC significantly improved germination percentage, shoot length, and biomass of maize seedlings as compared to other BCs and their respective control plants. However, acidified BCs caused a significant decrease in nutrient contents (P, K, Na) of soil,maize seedlings, and the soil organic matter contents as compared to non- acidified BCs. But when compared with control treatments, all BCs treatments (acidified and non-acidified) delivered higher levels of nutrients and organic matter contents. It was concluded that none of the BCs (acidified and non-acidified) had caused negative effect on soil conditions and growth of maize. In addition, the acidification of BC prior to its application to alkaline soils might had altered soil chemistry and delivered better maize growth. Moving forward, more research is needed to understand the long-term effects of modified BCs on nutrient dynamics in different soils. In addition, the possible effects of BC application timings, application rates, particle size, and crop species have to be evaluated systemtically.

Effects of local farming practices on soil organic carbon content, enzymatic activities, and microbial community structure in semi-arid soils of Morocco

Soil organic carbon (SOC) is essential in semi-arid agricultural land for enhancing soil health, particularly through the promotion of microbial activities. This study assessed the impact of different agronomic practices on soil properties, microbial communities, and SOC levels in semi-arid Moroccan wheat fields. Three treatments were investigated: eucalyptus (Eucalyptus spp.) companion planting (EU), and fallowing with harvest residue mulching (FA), with the latter involving both short (3 months; FAS) and long (15 months; FAL) fallow periods. The study revealed significant variation in soil characteristics and microbial communities between these agronomic management regimes. Notably, soils managed with FAL contained elevated SOC levels (1.2%) compared to other treatments (FAS and EU) which show lower SOC range (0.62–0.86%). Both labile C (water-soluble carbon) and recalcitrant C (humic substances) were increased by FAL. Additionally, soil microbial biomass and dehydrogenase activity were observed to be high in FAL-managed soils, along with increased levels of extracellular enzymes related to nutrient cycling (β-glucosidase, alkaline phosphatase, and urease). Phospholipid fatty acid (PLFA) analysis indicated positive correlation between carbon content in soils and microbial populations. In contrast, soils managed with EU had significantly lower SOC levels, possibly due to differences in carbon fractionation. FAL increased soil enzymatic activities and enriched the microbial community when compared to EU management. In conclusion, this study indicated the importance of fallowing and fallowing period for conservation of SOC, and potential to mitigate negative effects of biophysical constraints on agricultural productivity in semi-arid soils of Northwest Africa.

Soil bacterial community diversity and life strategy during slope restoration on an uninhabited island: changes under the aggregate spray-seeding technique.

We investigated the effects of the aggregate spray-seeding (ASS) technique on soil bacterial community diversity, life strategies, and seasonal change. Soil from six plots with original vegetation (CK, n=6) was compared to soil from 15 plots with spray-seeding restoration (SR, n=15) using environmental DNA sequencing. The bacterial Shannon and Chao1 indices of SR soils were significantly greater (P<0.05) than those of CK soils. The Chao1 index for the SR soil bacterial community was significantly greater in summer (P<0.05) than in winter. The ratio of the relative abundance of bacterial K-strategists to r-strategists (K/r) and the DNA guanine-cytosine (GC) content in the SR soil were significantly lower (P<0.05) than those in the CK soil. Principal coordinate analysis revealed significant differences between the SR and CK bacterial communities. The GC content was positively correlated with the K/r ratio. Soil conductivity was negatively associated with the K/r ratio and GC content, indicating that ionic nutrients were closely related to bacterial life strategies. The ASS technique improved soil bacterial diversity, altered community composition, and favored bacterial r-strategists.

Pb(II) and chlortetracycline immobilization and economy of biologically amended coastal soil

To study the pollutants immobilization and economy of biologically amended coastal soil, Alternanthera philoxeroides biomass (Bm), biochar (Bc), and dodecyldimethyl betaine (BS) modified Bc (BS-Bc) were used to amend coastal soil from Jialing, Fu, and Qu River. A runoff experiment was used to simulate the longitudinal migration and morphological changes of Pb(II) and chlortetracycline (CTC) in each amended coastal soil, and the economy of pollutants immobilization by different amended coastal soil were compared. The equilibrium time of Pb(II) and CTC in each amended coastal soil ranked in the order of BS-Bc-amended > Bc-amended > Bm-amended > unamended coastal soil. The average Pb(II) and CTC flow rate in different amended coastal soils presented an opposite trend with the equilibrium time. Pb(II) and CTC content all reduced with the increasing runoff length. Under the same soils, the content changes presented Bm and Bc amended > unamended > BS-Bc amended. CEC and clay content of coastal soils were the key factors affecting Pb(II) and CTC immobilization. The immobilization mechanisms were electrostatic attraction, ion exchange, surface precipitation, and complexation to Pb(II) and ion exchange and complexation to CTC. The economy of Pb(II) and CTC immobilization ranged from 0.5 to 9.0 and from 1.0 to 5.4 mg/¥, and coastal soil amended by BS-Bc had practical application value and high economy.

Characterization of Physicochemical Properties and and Heavy Metals Content of Soils under Kratom (Mitragyna speciosa) Cultivation, Kapuas Hulu District, Indonesia

Background: Kapuas Hulu is a district in West Kalimantan Province, Indonesia, which is famous for its production of kratom (Mitragyna speciosa), a traditional medicinal plant. Kratom is the main cultivated plant carried out by farmers. However, data regarding the physicochemical properties of kratom plantation soil are still limited, especially regarding the heavy metal content. This research aimed to determine the physicochemical properties and heavy metal content of soil planted with kratom. Methods: This research was conducted on alluvial soil and peat planted with kratom. This research is survey of 2 fields where sampling from each land was carried out using the diagonal method, where 5 sub-samples were taken per land and composited, except for volume Weight. Result: Mineral land and peat land can be used as land for Kratom cultivation because the physicochemical properties of both lands support the growth of Kratom plus the heavy metal content is below the critical threshold.

Dynamics of Water-Soluble Carbon and Nitrogen Content in Soils in the First Years after Clearcutting

Dynamics of Water-Soluble Carbon and Nitrogen Content in Soils in the First Years after Clearcutting

Enhancing sulfur absorption in soybean rhizosphere through arbuscular mycorrhizal fungi inoculation: Implications for soil health and crop growth

Soybean, a sulfur-loving cash crop, suffers from declining soil sulfur with continuous cropping, hindering its growth and development. Arbuscular mycorrhizal fungi (AMF) form beneficial partnerships with plant roots, aiding in nutrient uptake and promoting plant growth. Recent research has increasingly focused upon AMF's potential to enhance sulfur absorption through increased rhizosphere microbial activity. This study investigated the impact of AMF inoculation on soil organic sulfur mineralization, microbial community composition, and sulfur cycle function genes in the continuous cropping soybean rhizosphere. 16 S rRNA sequencing and high-throughput qPCR revealed changes in microbial community composition and the expression of sulfur cycle genes. ICP-MS measured total soil sulfur, and the BaSO4 turbidimetric method determined available sulfur. Following inoculation of continuous cropping soybean soil with AMF, it was observed that OTU1851, OTU1897, OTU2148, OTU3303, and OTU3738, five specific rhizospheric soil sulfur cycling microbial communities, were enriched. And AMF inoculation enhanced sulfur cycle function, the abundance of aspA, soxY and yedZ increased by 143.23 %, 236.04 % and 436.64 %. This led to increased soil arylsulfatase (S-ASF) activity (from 39.17 to 49.82 μg/(mL·h)), available sulfur content (from 12.88 to 17.55 mg/kg), and ultimately, improved soybean sulfur absorption and growth. Therefore, this study holds significant implications for improving available sulfur content and utilization in sulfur-deficient soils. Furthermore, it provides a theoretical basis for using AMF as a biofertilizer to remediate sulfur -deficiency, offering a sustainable and environmentally friendly solution.

Analysis of tough clay soil plastic index from several quarries in Aceh Besar District for seismic mitigation

Abstract Clay soils that tend to have the potential for landslides and earthquake-induced cracking are a serious problem in the development of infrastructure and settlements in the area. This research investigation sample was collected at a quarry in several areas of Aceh Besar District to identify problematic soil behavior in various quarries. The method used was stabilization by conducting compaction testing to obtain the optimum moisture content of the natural soil. The quarry soil samples taken were disturbed samples, which were then tested directly at the Soil Mechanics Laboratory. The data used in this study is the plastic index (PI) value. This research aims to assess stabilization strategies for problematic clay soils as an earthquake risk mitigation effort in the Aceh Besar region. The results of this study are expected to provide practical guidance for stakeholders in planning and developing more earthquake-resistant infrastructure in Aceh Besar. The result of the test showed that the OMC value was 36.3% with a dry weight of 1.22 gr/cm3.

Global pattern of organic carbon pools in forest soils.

Understanding the mechanisms of soil organic carbon (SOC) sequestration in forests is vital to ecosystem carbon budgeting and helps gain insight in the functioning and sustainable management of world forests. An explicit knowledge of the mechanisms driving global SOC sequestration in forests is still lacking because of the complex interplays between climate, soil, and forest type in influencing SOC pool size and stability. Based on a synthesis of 1179 observations from 292 studies across global forests, we quantified the relative importance of climate, soil property, and forest type on total SOC content and the specific contents of physical (particulate vs. mineral-associated SOC) and chemical (labile vs. recalcitrant SOC) pools in upper 10 cm mineral soils, as well as SOC stock in the O horizons. The variability in the total SOC content of the mineral soils was better explained by climate (47%-60%) and soil factors (26%-50%) than by NPP (10%-20%). The total SOC content and contents of particulate (POC) and recalcitrant SOC (ROC) of the mineral soils all decreased with increasing mean annual temperature because SOC decomposition overrides the C replenishment under warmer climate. The content of mineral-associated organic carbon (MAOC) was influenced by temperature, which directly affected microbial activity. Additionally, the presence of clay and iron oxides physically protected SOC by forming MAOC. The SOC stock in the O horizons was larger in the temperate zone and Mediterranean regions than in the boreal and sub/tropical zones. Mixed forests had 64% larger SOC pools than either broadleaf or coniferous forests, because of (i) higher productivity and (ii) litter input from different tree species resulting in diversification of molecular composition of SOC and microbial community. While climate, soil, and forest type jointly determine the formation and stability of SOC, climate predominantly controls the global patterns of SOC pools in forest ecosystems.