10-20cm Layer Research Articles

Assessment of Soil Carbon Stock Potential in Different Soil Layers of Grassland Ecosystems

Mostly soil carbon stock research is done in areas with natural vegetation, ignoring university campuses. This study assesses soil carbon stocks in different soil layers of grassland ecosystems within the Bharathiar University campus in Tamil Nadu, India. Soil samples were collected from grasslands in four sections (namely, East section, West section, North section, and South section) of the campus and analyzed for carbon content across depths of 0-10cm, 10-20cm, and 20-30cm. Results indicate soil carbon stocks in grassland ecosystems ranging from 1.36% to 2.26%, with notable variations observed among campus sections and soil layers. One-way ANOVA revealed that there is a significant variation in soil carbon stock values among the four sections in the 20-30cm layer (F(3,16)=3.865, p<0.05), but not for the 0-10cm layer (F(3,16)=1.454, p>0.05) and the 10-20cm layer (F(3,16)=3.011, p>0.05). Pearson’s Correlation analysis revealed that the soil carbon stock had no significant relationships with soil pH, Conductivity, and total dissolved solids at all four sections of the university campus, except for a positive correlation between soil carbon stock and total dissolved solids at the East section (r=0.563, p<0.05), and between soil carbon stock and soil pH at the South section (r=0.550, p<0.05). These findings underscore the complexity of soil carbon dynamics in grassland ecosystems of university campuses and emphasize the potential for localized assessments to inform sustainable land management strategies. This study contributes valuable insights into enhancing carbon sequestration efforts at the university campus, useful for global climate change mitigation. Integrating such localized findings into broader environmental policies can optimize carbon management strategies across similar ecosystems globally.

INDICATOR ATTRIBUTES OF SOIL QUALITY IN AREAS UNDER DIFFERENT LAND USE SYSTEMS, IN THE WESTERN AMAZON

The anthropization of natural environments, when performed inadequately, promotes the disruption of the ecological balance and can influence the fauna, flora and biodiversity in general, including the edaphic environment and its components. The objective was to evaluate the soil attributes in areas with different types of vegetation cover and different forms of soil management. The study was carried out in native forest area (Subperennial Equatorial Forest) and cultivated area (annual species), in Porto Velho, Rondônia, Brazil. Samples were collected in two layers (0-10 and 10-20cm), on a Latossolo Vermelho-Amarelo, to evaluate microbial biomass by the fumigation-extraction (FE) method, as well as the chemical and physical soil attributes. It was possible to verify a significant increase in soil density and reduction of moisture and improvement of chemical attributes resulting from the use of the area. The organic matter content decreased sharply in the managed area (25%), compared to the forest, in the superficial layer (0-10cm). Microbial C-biomass under the native forest showed 54% higher mean value (883 mgC g-1) compared to the managed area (410 mgC g-1) in the superficial layer. The microbial N-biomass ranged from 21.3 to 19.5 mgN.g-1 in the native forest area, and from 9.3 to 11.5 mgN g-1 in the managed area, respectively in the 0-10 and 10-20cm layers. In the native forest area, the addition of organic matter to the soil by the vegetation litter was an important conditioning factor for the microbial community, demonstrating the use of this attribute as an indicator of soil quality.

Physical fractions of organic matter and mineralizable soil carbon as quality indicators in areas under different forms of use in the Cerrado-Pantanal Ecotone

Understanding soil organic matter (SOM) dynamics is essential to employ management that contribute to the improvement of soil quality (SQ). The aim of this study was to characterize the SOM and evaluate the emission of mineralizable C (C-CO2) in different management systems. The soil was collected in five managed areas: exposed soil (ES), conventional tillage system (CTS), no-tillage system (NTS), permanent pasture (PP) and sugarcane (SC), in addition to a forest area (NF), in the layers of 0-5, 5-10, and 10-20cm. Total organic carbon (TOC), physical-granulometric fractionation of SOM were performed, determining the contents and stocks of particulate organic matter (C-POM; StockPOM) and mineral organic matter (C-MOM; StockMOM), in addition to calculating SQ indices. In addition to C-CO2 emissions from the soil. The areas of PP and NTS presented the highest levels of TOC in the surface layer. The highest levels of C-MOM and StockMOM were observed in the PP area, besides higher CSI (carbon stock index), reaching 1.67 in the 10-20cm layer. The areas of PP and SC were similar to the NF in all layers regarding CMI (carbon management index). In CTS, there were higher peaks in emissions and accumulation of C-CO2. It is evident that the improvements in the SQ in the areas of PP, SC, and NTS caused mainly by the deposition of plant material and by soil revolving not being performed. In the CTS, high emission peaks of C-CO2 show that the lack of conservation management practices contributes to the emission of greenhouse gases.

Hydropedological behavior of a chromic vertisol under different plant covers

Vertisols present edaphic limiting factors primarily of a physical nature. The study of their hydropedology, supported by multivariate techniques, is of vital importance. The work was developed with the objective of determining, through multivariate analysis, the hydropedological behavior of a Chromic Vertisol under different plant covers. In areas under natural grass, sugarcane, and secondary forest, belonging to the Holguín Sugarcane Provincial Research Station, three random points were chosen in each. Soil penetration resistance, soil bulk density, gravimetric moisture, and volumetric moisture at depths of 0-10, 10-20 and 20-30cm were determined. A Principal Component Analysis and Canonical Correlations were performed using Statistica 7 and Statgraphics Plus XV.II. The first two components made the greatest contribution to the variance, with 83.09%. The greatest contributions (1st component) were given by moisture at all depths and by soil compaction at a depth of 20-30 cm. The 2nd component was influenced by soil compaction in the 0-10 and 10-20cm layers. There was a contrast between the variables that characterize the solid phase with which they describe the liquid phase of the soil. There was a correlation between soil moisture and compaction. The first two pairs of canonical variables showed a strong linear correlation and regularly dispersed along the central values of the model, with a remarkable grouping by depths.

Community Composition and Co-Occurrence Patterns of Diazotrophs along a Soil Profile in Paddy Fields of Three Soil Types in China.

Diazotrophs play a key role in biological nitrogen (N2) fixation. However, we know little about the distribution of the diazotrophic community along the soil profile in paddy fields. Here, we used Illumina MiSeq sequencing, targeting the nitrogenase reductase (nifH) gene, to investigate changes with depth (0-100cm) in the diazotrophic community in paddy soils of three regions (Changshu, Hailun, and Yingtan) in China. The results indicated that most diazotrophs belonged to the phylum Proteobacteria, accounting for 78.05% of the total number of sequences. The diazotrophic diversity was generally highest in the 10-20cm layer, and then significantly decreased with soil depth. Principal coordinate analysis and PERMANOVA indicated that the diazotrophic community structure was significantly affected by region and soil depth. There were obvious differences in the composition of the diazotrophic community between the topsoil (0-40cm) and the subsoil (40-100cm). Anaeromyxobacter, Sideroxydans, Methylomonas, Nostoc, Methanocella, and Methanosaeta were enriched in the topsoil, while Geobacter, Azoarcus, Bradyrhizobium, and Dechloromonas were concentrated in the subsoil. Furthermore, co-occurrence network analysis showed that the diazotrophic network in the topsoil was more complex than that in the subsoil. Distance-based redundancy analysis indicated that soil total C and N content and pH were the main factors influencing the vertical variation in the diazotrophic community. These results highlighted that depth has a great impact on the diazotrophic diversity, community composition, and co-occurrence patterns in paddy soil.

Planting age of peach affects soil metal accumulation and distribution in soil profile.

Changes in soil available metal, particularly, distribution changes in the soil profile relative to long-term peach cultivation, have not been studied thoroughly. Soil samples at depths of up to 100cm in the soil profile were taken from peach orchards that were cultivated for 7, 15, and 50years. We analyzed available metals (Zn, Fe, Mn, Al, and Cu), soil pH, total nitrogen (TN), nitrate nitrogen (NO3--N), and ammonium nitrogen (NH4+-N) in different soil layers (0-10cm, 10-20cm, 20-40cm, 40-60cm, 60-80cm, and 80-100cm). The results showed that available metals were enriched in the topsoil (0-20cm) after 50years of peach cultivation, with the highest contents of available Fe (1.0mgkg-1), Al (188.2mgkg-1), and Cu (0.7mgkg-1) in the 10-20cm layer and Zn (11.7mgkg-1) in the 0-10cm layer. The soil pH in the 0-40cm layer decreased with increasing periods of peach cultivation, with the lowest pH (4.2) in the 10-20cm layer after 50years of peach cultivation. Soil pH was negatively correlated with available metals (R = - 0.579, P < 0.05 for Zn, R = - 0.727, P < 0.01 for Fe, R = - 0.792, P < 0.01 for Mn, R = - 0.690, P < 0.01 for Al, and R = - 0.783, P < 0.01 for Cu). The highest contents of NO3--N (212.9mgkg-1) and NH4+-N (10.2mgkg-1) were observed in the 50-year-old 0-10cm layer, and soil pH was correlated negatively with the contents of NO3--N and NH4+-N. Overall, our results indicated that the continuous input of nitrogen fertilizers may play an important role in soil acidification, and soil acidification may result in high accumulation of available metals in soil after long-term peach cultivation.

Changes in physical properties and organic carbon of a Kandiudox fertilized with manure

ABSTRACT: Successive applications of pig slurry and poultry manure can improve the soil structure, according to the land use conditions and amounts applied. This study evaluated the effect of manure fertilization on the physical properties and organic carbon of a Rhodic Kandiudox. Treatments included land use and management and time of pig slurry and poultry litter application, namely: native forest (NF); yerba mate after 20 years of animal waste application (YM20); pasture after 15 years of application (P15); grassland after 20 years of manuring (PP20); grassland after 3 years of manuring (P3); pasture without application (P0), maize after 20 years of application (M20); and maize after 7 years of application (M7). Soil samples were collected in the 0-5, 5-10 and 10-20cm layers, in which density, porosity, aggregate stability, flocculation, penetration resistance, available water, and total clay content, total and particulate organic carbon, and C:N ratio were analyzed. The total organic carbon is sensitive to management and was not related to waste application, except in the 10-20cm layer of ryegrass pasture after three years of manuring. Reponses to waste application and land use and management systems were observed in the variables soil density and penetration resistance.

Soil organic carbon beneath croplands and re-established grasslands in the North Dakota Prairie Pothole Region.

Grassland ecosystems established under the conservation reserve program (CRP) in the Prairie Pothole Region (PPR) currently provide soil conservation and wildlife habitat services. We aimed to determine if these lands also sequester soil organic carbon (SOC), as compared with neighboring croplands across multiple farms in the North Dakota PPR. We sampled soil from small plots at 17 private farms in the central North Dakota PPR, where long-term (≥15years) grasslands managed under the CRP were paired with neighboring annual croplands. Cores were collected to 100cm and split into 0-10, 10-20, 20-30, 30-40, 40-70, and 70-100cm soil depth layers. We hypothesized the effect of land use on soil organic carbon (SOC), root carbon (C), and bulk density would be greatest near the surface. For 0-10 and 10-20cm layers, grasslands managed under the CRP were lower in bulk density and higher in SOC. From 0 to 70cm, grasslands managed under the CRP were higher in root C. Average (±standard error) SOC for re-established grasslands and croplands was 25.39 (0.91) and 21.90 (1.02), respectively, for the 0-10cm soil layer and 19.88 (0.86) and 18.31 (0.82), respectively, for the 10-20 soil layer. Compared to croplands, re-established grasslands sampled in the North Dakota PPR were 3-13% lower in bulk density and 9-16% higher in SOC from 0 to 20cm, while root C was 2-6 times greater from 0 to 70cm.

Effects of Nitrogen Deposition on Soil Nutrient Content of &lt;i&gt;Deyeuxia angustifolia&lt;/i&gt;

Taking the marsh meadow Deyeuxia angustifolia in San Jiang Plain of Northeast China as test material,a field experiment was carried out with treatments different in nitrogen supply (0,4,8g/m2) to investigate the effects the soil nutrient content.The results showed that difference among layers soil organic matter activity firstly increased and then decreased with increasing of nitrogen addition. Difference among layers soil total nitrogen contains were no significant differences. Soil total nitrogen contains reduced gradually in the 0-10cm layers,in the 10-20cm and 20-30cm layers firstly increased and then decreased. Difference among layers soil ammonium N contains were no significant differences.The 0-10cm and 20-30cm layers soil total NO-3-N firstly increased and then decreased,10-20cm layers firstly decreased and then increased. Difference among layers soil nitrate N contains obviously different levels (p&lt;0.05). With increasing of nitrogen addition, the 0-10cm and 10-20cm layers soil total phosphoru contains increased gradually,20-30cm layers firstly increased and then decreased. With increasing of nitrogen addition,difference among layers soil total potassium contains were no significant differences.

Aboveground Biomass of &lt;i&gt;Reaumuria soongorica&lt;/i&gt; Shrub Effect on Soil Moisture and Nutrient Spatial Distribution in Arid and Semi-Arid Region

In order to revel aboveground biomass of R. soongorica shrub effect on soil moisture and nutrients spatial distribution, and explore mechanism of the changes of soil moisture and nutrients, soil moisture content, pH, soil organic carbon (SOC) and total nitrogen (TN) at three soil layers (0-10cm,10-20cm, and 20-40cm) along five plant biomass gradients of R. soongorica were investigated. The results showed that soil moisture content increased with depth under the same plant biomass, and increased with plant biomass. Soil nutrient properties were evidently influenced with plant biomass, while decreased with depth. SOC and TN were highest in the top soil layer (0-10 cm), but TN of 10-20cm layer has no significant differences (P &lt; 0.05). Moreover, soil nutrient contents were accumulated very slowly. These suggests that the requirement to soil organic matter is not so high and could be adapted well to the desert and barren soil, and the desert plant R. soongorica could be acted as an important species to restore vegetation and ameliorate the eco-environment.