Soil Physical Parameters Research Articles

Impact of Vermicomposting with Soil Enriched with Plastic and Different Biodegradable Wastes on Physical, Chemical, and Biological Parameters of Soil

Impact of Vermicomposting with Soil Enriched with Plastic and Different Biodegradable Wastes on Physical, Chemical, and Biological Parameters of Soil

Rice-based Climate Resilient Farming Practices Influencing the Soil Physical Parameters, Carbon Dynamics and System Productivity in Inceptisols under Coastal Agro-ecosystem

A field experiment was carried out to assess the influence of different rice establishment technique {System of Rice Intensification (SRI) and Conventional method of transplanting (CMT)}, rice-based cropping sequence {rice-groundnut-fallow (RGF) and rice-toria-greengram (RTG)}, mulching practices {No mulching (WoM) and Crop residue mulch (CRM)} and nutrient management practices{100% recommended dose of fertilizer (RDF) and 75% RDF + 25% N through FYM (INM)} on the different physical properties of the soil under changing climate at the Central Research Station, Odisha University of Agriculture and Technology, Bhubaneswar in the East and South Eastern Coastal Plain Zone of Odisha, India. The field experiment was conducted in split-plot design replicated thrice. Considerable build-up of SOC by 5.2%, 10.3% and 13.9% was observed under RTG, CRM and INM over RGF, WoM and RDF, respectively. Both CRM and INM registered higher proportion of water stable micro (14.8 %and 15.7 %) and macro-aggregates (5.2 % and 9.2 %), respectively over WoM and RDF. The CRM and INM remarkably elevated the macro-aggregate carbon by 13.9 % and 15.7 %, respectively over the initial contents (10.2 g kg-1). Additionally, the RGF and CRM recorded significantly higher REY of 9.2 t ha-1 and 9 t ha-1 over RTG and WoM treatments, respectively. Thus, SRI system along with mulching rice straw in toria and toria biomass to green gram and INM practices has been identified as the most suitable climate resilient farming practice in the coastal agro-ecosystem of Odisha, India because of its significant impact in soil physical properties including carbon storage, and thus synergizing effects for favourable soil ecosystem functioning.

Физические и физико-химические свойства почв рекреационных территорий г. Воронежа

Using the example of four key sites, soil formation factors, morphogenetic features of soils exposed to recreational stress are described, and the physical and physico-chemical properties of the soils of the studied territories are studied. Keywords: PHYSICAL PARAMETERS OF SOILS, PHYSICO-CHEMICAL PARAMETERS OF SOILS, GRANULOMETRIC COMPOSITION, HUMUS, RECREATIONAL LOAD, PROPERTIES OF FOREST SOILS

Thermal conductivity of urban and artificial soils: methodological aspects and mathematical modeling

There are various methods for experimental determination of the thermal conductivity dependence on soil moisture and substrates. The influence of the sample structure (monolith, bulk sample), sample temperature, the method of installing the probe into the sample on the obtained readings of the TEMPOS device was studied and methodological recommendations were proposed. The dependence of thermal conductivity of soils bulk samples and substrates on moisture is shown. The spread of thermal conductivity values in the moisture range from hygroscopic to full moisture capacity for soddy-podzolic soil is 0.229–1.430 W/(m*K), for peat – 0.250–0.521 W/(m*K), for sand – 0.280–2.605 W/(m*K), for a mixture – 0.234–1.568 W/(m*K). ). The influence of properties such as density, particle size distribution, specific surface area, organic matter content, salinity affected thermal properties to a lesser extent. The established patterns can be used to calculate the temperature regime of soils in solving a number of applied problems related to the construction of special soil objects, for example, when creating urban soil structures. For this, it is necessary either to determine the thermal conductivity experimentally, or to calculate it, using the physical parameters of soils and substrates. The first method is labor-consuming, the second is less accurate. As an example, the equations available for work in the HYDRUS-1D (Chang–Horton and Campbell) model are used. These equations either overestimate the thermal conductivity in the area of high substrate humidity, or underestimate the thermal conductivity in the area of low substrate humidity (sand, loam, peat and a mixture based on them).

Long-Term Effect of Crop Establishment Methods and Tillage Practices on Soil Physical Properties in Rice-Wheat System

ABSTRACT Rice-wheat system, the most prevalent cropping system of the Indo-Gangetic plain, nowadays poses a threat to its sustainability owing to deterioration of soil physical parameters, disposal of rice straw and declining yield trends. The present study was aimed to identify the best option of crop establishment, tillage and rice straw retention in rice-wheat system after long-term (2010–2020). The field experiment was conducted on typic Ustochrept sandy clay loam soil. Treatments comprised direct seeded rice with zero tillage (DSRZT), direct seeded rice with conventional tillage (DSRCT), direct seeded rice with reduced tillage (DSRRT) and puddled transplanted rice (PTR) in rice as main plots; and conventionally tilled without rice residue (CTW), zero tilled without residue (ZTW) and zero tilled wheat with residue retention (ZTW+R) in wheat as sub plots. The results revealed that physical parameters like bulk density and soil penetration resistance decreased while, plant available water content, infiltration and hydraulic conductivity of the soil increased significantly in DSRZT, DSRRT and ZTW+R compared to PTR and CTW. Amount of organic carbon enhanced from .42% to .55% and .34% to .39% in both 0–15 and 15–30 cm soil layers, respectively, in DSRZT compared to PTR. Aggregation status also improved in ZT-based treatments in contrast to PTR and CTW treatments. However, the average grain yield of rice was higher by 2.15–19.4% in PTR compared to DSR treatments while; ZTW+R had an advantage of 4.98% and 7.75% in contrast to CTW and ZTW, respectively, in terms of average wheat yield.

The potato rhizosphere microbiota correlated to the yield of three different regions in Korea

We examined potato rhizosphere bacterial and fungal communities across three regions: Cheongju, Pyeongchang, and Gangneung. These regions have varying soil and climate conditions, resulting in different yields. We found that precipitation was the main limiting factor in our study while soil physiochemical factors affect bacterial and fungal microbiota in correlation with yield. Both bacterial and fungal microbiota showed distinct patterns according to the regions. ASVs positively correlated with yield were predominantly found in the Pyeongchang region which also produced the highest yields, while ASVs negatively correlated with yield were associated with Gangneung where the lowest yields were observed. The greatest bacterial and fungal diversity was detected in Pyeongchang consisting of Propionibacteriales, Burkholderiales, and Vicinamibacteriales. Gangneung, on the other hand primarily belong to Sordariales, Mortierellales, Cystofilobasidiales, and Tremellales. The putative yield-negative ASVs detected in Gangneung may have been influenced by drought stress. This work has highlighted key bacterial and fungal taxa as well as core taxa that may potentially be associated with high and low yields of potato in relation to metadata which includes soil chemical and physical parameters as well as weather data. Taken together we suggest that this information can be used to assess site suitability for potato production.

Soil quality increases with long-term chabazite-zeolite tuff amendments in arable and perennial cropping systems

The application of natural zeolites to improve soil quality and functioning has become highly popular, but we still miss information about the long-term effects on the soil due to its application. This study assesses the soil quality index (SQI) of three distinct agricultural soil systems 6–10 years after a single application of natural chabazite zeolite as a soil amendment. These soils exhibit different management practices: intensive arable (cereals), intensive perennial (pear) and organic perennial (olive). In the arable system, a zeolite application dosage of 5, 10 and 15 kg m−2 was tested and compared to unamended soil. In the two perennial systems, an application of 5 kg m−2 was tested against untreated reference sols. A set of 25 soil physical, chemical and biological parameters linked to soil health and quality were analysed at each experimental site. The dataset was investigated through Principal Component Analysis (PCA) to calculate the soil quality index (SQI) using linear scoring.In the arable-cereal field, the SQI doubled (0.3 to ca. 0.6 for all amendments) in chabazite-amended plots; a dose effect was not recognizable. In both perennial fields, the SQI was significantly higher in the chabazite-amended plots (5 kg m−2) with similar increases as compared to the arable-cereal field. At each site, the indicators selected by the PCA were different, indicating that chabazite addition impacted soil quality differently in each cropping system. Overall, the results highlighted a significant increase in soil quality with chabazite amendment, which confirms its potential for increasing soil health in the long-term.

Experimental Study on the Soil Conditions for Rapeseed Transplanting for Blanket Seedling Combined Transplanter

To address the lack of available information on the soil physical conditions suitable for rapeseed blanket-shaped seedling transplanting, as well as the lack of protocols for the optimisation of soil tillage components in the utilisation of an integrated rapeseed blanket seedling combined transplanter, the physical parameters of different soil conditions and their impact on the growth of rapeseed after transplanting were investigated in this study. The aim was to determine the suitable soil physical parameters for rapeseed blanket-shaped seedling transplanting. First, the changes in soil firmness, soil bulk density, and soil moisture content during the installation of the rapeseed blanket seedling combined transplanter were tested and analysed, providing preliminary data for subsequent research. Using the variables of soil firmness and soil moisture content in the micro-environment around the roots and stems (30–50 mm) after rapeseed seedling transplantation and indicators such as the survival rate, root diameter, seedling height, and dry weight, an experiment on the growth of rapeseed blanket-shaped seedlings was conducted based on the furrow cutting transplanting principle. The results indicated that during the initial stage of rapeseed transplanting, the soil moisture content significantly influenced the vitality of the rapeseed plants. Under a high soil moisture content, the typically lengthy seedling period was shortened, and the effect on vitality was good, with minimal influence from the soil firmness. After seedling establishment, the rapeseed growth was significantly affected by the soil firmness. When the soil moisture content was less than 20%, increasing the soil firmness to 500 kPa was beneficial for moisture retention and rapeseed seedling growth. At a soil moisture content ranging from 20 to 25%, a soil firmness of 400 kPa was most suitable for both rapeseed vitality and late-stage growth. When the soil moisture content exceeded 25%, reducing the soil firmness to 300 kPa was beneficial for rapeseed growth, as an excessively high moisture content may lead to soil compaction, affecting seedling development. This study provides a theoretical basis for optimizing the design of soil tillage components in the application of an integrated rapeseed blanket seedling combined transplanter and for the high-yield management of rapeseed after transplanting.

Soil Moisture Conservation through Crop Diversification and Related Ecosystem Services in a Blown-Sand Area with High Drought Hazard.

Soil moisture reserves are a key factor in maintaining soil fertility and all other related ecosystem services (including carbon sequestration, soil biodiversity, and soil erosion control). In semiarid blown-sand areas under aridification, water preservation is a particularly crucial task for agriculture. The international Diverfarming project (2017-2022), within the EU Horizon 2020 Program, focused on the impacts of crop diversification and low-input practices in all pedoclimatic regions of Europe. In this three-year experiment conducted in the Pannonian region, the impact of intercropping asparagus with different herbs on some provisioning and regulating ecosystem services was evaluated in the Kiskunság sand regions. Relying on findings based on a range of measured physical and chemical soil parameters and on crop yields and qualitative properties, advice was formulated for farmers. The message drawn from the experiment is somewhat ambiguous. The local farmers agree that crop diversification improves soil quality, but deny that it would directly influence farm competitiveness, which primarily depends on cultivation costs (such as fertilization, plant protection, and labour). Further analyses are needed to prove the long-term benefits of diversification through enriching soil microbial life and through the possible reduction of fertilizer use, while water demand is kept at a low level and the same crop-quality is ensured.

Heterogeneity in Arbuscular Mycorrhizal Fungi and Plant Communities of the Brazilian Cerrado, Transitional Areas toward the Caatinga, and the Atlantic Forest.

The Cerrado is the most diverse tropical savanna worldwide and the second-largest biome in South America. The objective of this study was to understand the heterogeneity and dynamics of arbuscular mycorrhizal fungi (AMF) in different types of natural Cerrado vegetation and areas that are transitioning to dryer savannas or tropical rainforests and to elucidate the driving factors responsible for the differences between these ecosystems. Twenty-one natural sites were investigated, including typical Cerrado forest, typical Caatinga, Atlantic Rainforest, transitions between Cerrado and Caatinga, Cerrado areas near Caatinga or rainforest, and Carrasco sites. Spores were extracted from the soils, counted, and morphologically analyzed. In total, 82 AMF species were detected. AMF species richness varied between 36 and 51, with the highest richness found in the area transitioning between Cerrado and Caatinga, followed by areas of Cerrado close to Caatinga and typical Cerrado forest. The types of Cerrado vegetation and the areas transitioning to the Caatinga shared the highest numbers of AMF species (32-38). Vegetation, along with chemical and physical soil parameters, affected the AMF communities, which may also result from seasonal rainfall patterns. The Cerrado has a great AMF diversity and is, consequently, a natural refuge for AMF. The plant and microbial communities as well as the diversity of habitats require urgent protection within the Cerrado, as it represents a key AMF hotspot.

Influence of soil physicochemical properties on diversity and distribution of aquatic vegetation in the riverine forested habitats

Riverine flora is one of the most dynamic aspects of a landscape, and it involves species which are adapted and specialised to grow in a range of environmental conditions. An ecological analysis was conducted to describe the phyto-sociological and floristic structure of the plant species in the riverine forest at Balloki along moisture gradients caused by river bank. A random quadrat method with a quadrat size of 1 × 1 m was used for sampling of the riverine site. All plant species growing in the riverine habitats were collected and identified. A detailed survey was conducted to record the ecological attributes such as density, frequency, cover, and importance value. These values were then used to calculate the relative values of these ecological indicators. These ecological indicators were correlated with various soil physical parameters (soil texture, moisture contents and saturation percentage), chemical properties (ECe and pH), and nutrients (Na, Ca, K and N). Most of the species were linked to sites 3 and 4 with high moisture content, low ECe, acidic pH and moderate nutrient composition. The species with the highest ecological importance were Cynodon dactylon, Rumex dentatus and Saccharum spontaneum which accounted for more than 80% of the total abundance. It was concluded that species distribution differed significantly along the four study sites mainly depending on the soil-physicochemical features of the study sites.

Biochemical Health of Soil of a Wide Agricultural Land of Birbhum DistrictinWest Benga

For many years soil analysis has been used as an aid to assess biochemical health of soil and plant nutrient management. Achieving and maintaining appropriate level of soil fertility, especially plant nutrient availability is of paramount importance if agri-cultural land is to remain capable of sustaining crop production at an acceptable lev-el. The Birbhum district, known for its agricultural practices, faces several challenges related to pollution arising from farming activities. Soil sampling and analysis is the first of three important steps in managing the nutrients required by plants. The sec-ond is the interpretation of analytical data leading to the third step, recommendation for nutrient addition. In this paper we would like to explore the biochemical health of soil of Birbhum District having widespreadagricultural land. Through analysis we would like to explore the availability of phosphorus, nitrogen and potassium, physical, physiochemical and chemical parameters of the agricultural soil. It will give a better future to poor farmers of this region through good production of crops and simulta-neously the economic condition of this region will improve.

Microarthropod as soil quality indicator for ravenous soils of North-West Bundelkhand region

In this study microarthropod population was compared with established soil quality index (SQI), so that indicator potential of soil microarthropods could be established. Forty-three georeferenced sites based on advanced techniques were selected from the major representative land uses viz., arable land, forest, grazing land and degraded land that fall under four administrative districts viz., Datia, Jalaun, Hamirpur and Tikamgarh. The samples were analysed for soil physical, chemical, and biological parameters. The soil quality index (SQI) was computed using minimum data set derived through principal component analysis and based on expert opinion. Soil organic carbon, microbial biomass carbon, nitrogen, potassium, and clay content were selected as contributors of soil quality index. Regression between SQI and micro arthropod abundance established a definite relationship, establishing that the soil micro arthropods might be used as soil quality index for monitoring soil quality for this geography.

Soil management affects soil C and N stocks but not overall soil health

Soil health describes a soil’s capacity to function as a vital ecosystem that sustains plants, animals, and humans. It can be assessed by measuring specific soil physical, chemical, and biological parameters combined into a soil health index (SHI). The objective of this study was to evaluate the effect of management, depth, and their interaction on soil health indicators. We evaluated long-term continuous tillage, horticultural crop rotation, which had an antecedent tropical pumpkin/bean rotation, and a no-till avocado orchard in a Cumulic Haplustolls at the Juana Díaz Agricultural Experiment Substation. Soil samples were taken at 0 to 15, 15 to 30, 30 to 50, 50 to 75, and 75 to 100 cm intervals using a hydraulic probe. Soil pH, electrical conductivity, bulk density, dry stable aggregates, mean weight diameter, tensile strength, carbon and nitrogen stocks, and water content were quantified. The data were analyzed in a multivariate ANOVA. Results were classified considering threshold values, and an SHI score was determined based on the simple additive method. Our findings show that the no-till avocado orchard had better soil physicochemical qualities, including higher C and N stocks, but this did not lead to an improved SHI score when compared with the continuous tillage crop rotation plot. Soil depth, management, and their interaction were significant effects in both management systems with a score of 0.55 on the SHI scale. These results imply that, although overall soil health is not affected, increased C concentration, no-till, and perennials have a favorable effect on SHI indicators in horticultural systems in the San Antón series.

Towards Sustainable Farming: Leveraging AIoT for Precision Water Management and Crop Yield Optimization

Sustainable Development Goals (SDGs) by the United Nations have Zero Hunger and Responsible Consumption and Production as the two significant agriculture-related components. Conventional irrigation control systems, relying heavily on manual labour, exhibit shortcomings in minimizing farmer input dependency. Recognizing the critical interdependence of water resource management, crop yield optimization, and environmental preservation, this work contends that precision in water management is essential. While efforts to reuse treated wastewater offer potential water conservation solutions, they often compromise crop yield. Precisely calculating water requirements can enhance crop yield, reduce human involvement, eliminate potential decision-making errors, and address water conservation issues. Automating tasks like irrigation demands comprehensive knowledge of crop and soil characteristics, climate conditions, time factors, and physical parameters like temperature, soil moisture, and humidity. This research addresses the limitations of current agricultural practices by advocating for a paradigm shift towards sustainable farming through the integration of Artificial Intelligence of Things (AIoT). The proposed framework leverages the fusion of the Artificial Intelligence (AI) and Internet of Things (IoT) to automate irrigation by employing a comprehensive analysis of diverse parameters. Through empirical evaluation, this work demonstrates that AIoT-based precision water management not only improves crop yield but also reduces human intervention, addressing water conservation challenges, and fostering sustainable agriculture practices.

Physical Conditions That Limit Chickpea Root Growth and Emergence in Heavy-Textured Soil

The tillage method determines several soil physical parameters that affect the emergence of post-rice chickpea (Cicer arietinum L.) in the Indo-Gangetic Plain of South Asia. Mechanised row-sowing with minimum soil disturbance and crop residue retention in medium-to-heavy-textured soils will alter the seedbed when compared to that prepared after traditional full tillage and broadcast sowing. Whilst minimum soil disturbance and timely sowing may alleviate the soil water constraint to crop establishment, other soil physical properties such as soil strength, bulk density, and aggregate size may still inhibit seedling emergence and root elongation. This study’s objective was to determine the limitations to chickpea crop establishment with increasing bulk density and soil strength, and different aggregate sizes below and above the seed. In two growth cabinet studies, chickpea seed was sown in clay soil with (i) a bulk density range of 1.3–1.9 Mg m−3 (Experiment 1) and (ii) the combination of bulk densities (1.3 and 1.8 Mg m−3) and aggregate sizes (<2 mm and >4 mm) above and below the seed (Experiment 2). Root length was significantly reduced with increasing bulk density (>1.4 Mg m−3), and soil strength impeded early root growth at >1 MPa. Where main root growth was impeded due to high bulk density and soil strength, a greater proportion of total root growth was associated with the elongation of lateral roots. The present study suggests that the soil above the seed needs to be loosely compacted (<1.3 Mg m−3) for seedling emergence to occur. Further research is needed to determine the size of the soil aggregates, which optimise germination and emergence. We conclude that soil strength values typical of field conditions in the Indo-Gangetic Plain at sowing will impede the root growth of chickpea seedlings. This effect can be minimised by changing tillage operations to produce seedbed conditions that are within the limiting thresholds of bulk density and soil strength.

Opening up the subsoil: Subsoiling and bio-subsoilers to remediate subsoil compaction in three fodder crop rotations on a sandy loam soil

The intensification of modern arable farming has brought on a steady increase of the risk of soil compaction, while simultaneously pushing the impact deeper into the soil profile. In the subsoil, outside the reach of regular tillage operation, it can become exceedingly difficult to deal with compacted layers. Commonly, farmers turn towards mechanical remediation strategies, like subsoiling, to deal with this issue. However, the numerous drawbacks that come with these operations have prompted the search for more sustainable alternatives, like bio-subsoilers, which are deep-rooting plant species with the capacity to penetrate compacted subsoil layers. This study aimed at investigating both mechanical and biological remediation strategies in a side-by-side comparison. The effectiveness of subsoiling and the use of two deep rooting (cover) crops (i.e. alfalfa and fodder radish) as remediation measures to alleviate subsoil compaction was assessed in terms of soil quality indicators, like penetration resistance, bulk density, porosity, plant available water capacity, air capacity and air permeability at 35 and 45 cm depth, and the above- and belowground growth of the main crop. In addition, a combination of both subsoiling and use of deep rooting (cover) crops was included to evaluate the potential role of the latter in protecting the mechanically loosened subsoil from recompaction. This complex comparison was done in three distinct maize-based fodder crop rotations (rotation 1: maize monoculture; rotation 2: maize/winter cereal rotation with fodder radish as cover crop after winter cereal; rotation 3: maize/winter cereal/alfalfa rotation). The study field (sandy loam soil) was selected based on the presence of a highly compacted layer at the interface between topsoil and subsoil (30–50 cm). The experiment demonstrated that subsoiling is an effective remediation measure to disrupt heavily compacted layers in the upper-subsoil, at least in the short-term. The crop response was however highly variable and only positive when the opportunity of reaching the subsoil proved to be advantageous for the crop (i.e. dry season). Besides its high degree of variability between years, the effects also proved to be very short-lived under a standard arable fodder crop rotation. Including deep rooting (cover) crops, like fodder radish and alfalfa, and limiting the initial subsoil disruption helped to partially stabilize the disrupted subsoil and reduce recompaction. Fodder radish and alfalfa penetrated the compacted subsoil without previous disruption by subsoiling. However, this did not lead to a significant improvement of the measured soil physical parameters.

N2O emissions from cropland and grassland management systems are determined by soil organic matter quality and soil physical parameters rather than carbon stock and denitrifier abundances

Understanding the relationship between soil organic carbon (SOC) storage and nitrous oxide (N2O) fluxes is crucial for sustainable land management. In this study, we examined this relationship in different cropping systems, including annual cropping systems with a legacy of varying durations (3 versus 6 years) of grasslands and continuous grassland. The aim was to investigate (1) the effect of contrasting management practices on SOC storage and N2O emissions under field conditions and (2) to elucidate the drivers of N2O emissions under controlled conditions. Our findings showed that despite the influence of management practices on SOC stocks, no trade-off was observed between SOC storage at two different depths (10 and 30 cm) and N2O emissions. Furthermore, we found that SOC chemical signature, soil physical characteristics, and denitrifier activity, rather than SOC content and denitrifier abundances, were the primary factors determining N2O emission potential. It is interesting to note that although functional gene abundances were related to denitrifier activities, they did not show a direct correlation with N2O emissions. This suggests that environmental factors and microbial activity play a more substantial role in determining N2O emissions than denitrifier abundances. The inclusion of temporary grassland in a crop rotation had a positive impact on SOC stocks, either by improving or maintaining their levels. However, as a trade-off the introduction of temporary grassland also led to higher N2O emissions. These increased emissions were not directly associated with the amount of SOC stored in soil but rather with changes in soil physical and chemical conditions.Our research emphasizes the importance of understanding the complex relationships among soil characteristics, management techniques, and N2O emissions to develop practical mitigation plans for building more sustainable agricultural systems.

Assessing the differences of two vineyards soils’ by NIR spectroscopy and chemometrics

Soil properties influence greatly the status of vine plants which consequently influences the quality of wine. Therefore, in the context of viticulture management, it is extremely important to assess the physical and chemical parameters of vineyards soils. In this study, the soils of two vineyards were analysed by near-infrared (NIR) spectroscopy and established analytical reference procedures. The main objective of this study was to verify if NIR spectroscopy is a potential tool to discriminate the soils of both vineyards as well as to quantify differences of soil's parameters. For that, a total of eight sampling spots were selected at each vineyard taking into consideration the soil type and sampled at different depths. The data analysis was performed using analysis of variance (ANOVA), principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) and partial least squares (PLS) regression. The ANOVA results revealed that 12 out of the 18 parameters analysed through the reference procedures can be considered statistically different (p < 0.05). Regarding PCA, the obtained results revealed a clear separation between the scores of both vineyards either considering NIR spectra or the chemical parameters. The PLS-DA model was able to obtain 100 % of correct predictions for the discrimination of both vineyards. PLS regression analysis using NIR spectra revealed R2P and RER values higher than 0.85 and 10, respectively, for 8 (pH (H2O), N, Ca2+, Mg2+, SB, CEC, ECEC and GSB) of the 18 chemical parameters evaluated. Concluding, these results demonstrate that it is possible to discriminate the soils of the different vineyards through NIR spectroscopy as well as to quantify several chemical parameters through soils NIR spectra in a rapid, accurate, cost-effective, simple and environmentally friendly way when compared to the reference procedures.

Shrubification and snow removal have an antagonistic effect on the accumulation of rhizosphere organic carbon components in peatlands

A warming climate will cause shrubification and less winter snow cover in peatlands, which are an important global carbon sink. Both shrubification and snowpack reduction affect organic carbon sequestration, yet their effects on the dynamics of microbial necromass carbon (MNC) and plant necromass carbon (PNC) in rhizosphere soil are indeterminate. This investigation focuses on the effects of shrubification and snow cover changes on organic carbon components and their mechanisms in rhizosphere soil. For this purpose, a field in situ experiment on snow cover removal and natural snow cover was conducted in shrub and herb peatlands, respectively, in winter, and rhizosphere soil samples were collected in the following growing season. The MNC biomarker amino sugar and the PNC biomarker lignin phenol were quantified, and in addition to the general soil physical, chemical, and biological parameters, root exudates were measured based on untargeted metabolomics. The findings showed that MNC contributes more to SOC in spring, with the majority of it derived from fungal necromass carbon, and the contribution of PNC to SOC gradually increased in later seasons, with a consequent decrease in rhizosphere SOC stability. Shrubification decreased the MNC content by 15.80% and the PNC content by 7.68%, whereas snow removal increased the MNC content by 8.24% and 2.58% and the PNC content by 11.31% and 17.39% in shrub and herb peatlands, respectively. The changes in root exudates may be an important factor regulating the accumulation of different SOC components. Specifically, sugars and amino acids had a positive priming effect on MNC and PNC, whereas organic acids had a negative priming effect. The mechanisms by which root exudates mediated MNC and PNC accumulation differed depending on the season. This research will be useful in forecasting future changes in carbon sink function and providing a theoretical foundation for increasing carbon sink measures.