Pasture Soils Research Articles

Distribution and Speciation of Trace Elements in Soils of Four Land-Use Systems

Land use has a greater impact on trace element (TE) concentration present in soils. In mountainous regions of the western Himalayas, some dominating geogenic and human-dependent anthropogenic factors are involved in the spatial distribution of TEs in various land uses. Soil samples were collected from permafrost, pasture, forest, and agricultural land-use systems of Babusar Valley and Fairy Meadows in Diamer districts and the Rama region in Astore Districts in replications for investigation of three TEs, i.e., copper (Cu), zinc (Zn), and nickel (Ni). These samples were analyzed for exchangeable, adsorbed, organically bound, carbonate precipitated, and residual forms. Significant differences among these TEs were observed. Differences in the levels of TEs within soil samples were observed to be influenced by land usage patterns. The physicochemical properties of soil samples were also investigated. Additionally, the total metals (Ni, Zn, Cu) were extracted and their concentrations were measured in all samples. The concentration of soil TEs was observed in the following order: adsorbed < organically bound < exchangeable < residual < carbonate precipitated form across all the land uses. The results indicate that the contents of TEs (Ni, Zn, Cu) in agricultural soils were greater than in the permafrost pasture and forest soil samples. The total TE concentration varied as Zn > Ni > Cu irrespective of the area and land uses. We believe this work will open avenues for researchers to explore TEs in various regions of the world.

Bacterial diversity and detection of resistance genes to broad-spectrum betalactams in dairy family farm soils

Bovine mastitis is a complex disease that brings great losses to the dairy producer. The microbial diversity of the soils, as well as the presence of resistance genes in the environment directly influence the maintenance of mastitis in the farm. The objective of this work was to analyze the bacterial diversity in pasture soils of a dairy family farm, detecting enterobacteria that may be involved in the etiology of bovine mastitis, and to detect genes that encode broad-spectrum betalactamases in these soils. Twelve soil samples, representative of different areas of the farm located in the municipality of Barra do Piraí, Rio de Janeiro, were collected at different times of the year. Total DNA was extracted from the samples, gene amplified by Nested-PCR and then the amplification products were separated by DGGE (Denaturing Gradient Gel Electrophoresis). With the DGGE it was possible to construct dendograms that effectively represented the bacterial diversity of these soils. Eight of the soil samples were used to amplify the genes encoding the betalactamase enzymes TEM (blaTEM gene), SHV (blaSHV gene) and CTX (blaCTXM gene). In three of the eight soil samples, the blaSHV gene was found to be present. The blaTEM and blaCTX-M genes were not detected in any of the samples. The detection of genes encoding broad-spectrum betalactamases in dairy cattle pasture soils is of concern, because the transfer of gene material between pathogenic and non-pathogenic bacteria in this environment is a reality.

The effect of antecedent soil moisture conditions on soil nitrous oxide and dinitrogen dynamics after wetting: An intact soil core study

Ruminant excreta urinary‑nitrogen (N) deposited onto pasture soil generates inorganic-N concentrations in excess of the pasture's immediate requirements. Consequently, nitrous oxide (N2O) and dinitrogen (N2) may be emitted from the urine-affected soil via denitrification. Soil moisture plays a key role in determining the end-product of denitrification. Although the effects of soil moisture and drying-wetting cycles on soil N2O production have been widely studied using sieved soils in a controlled environment, these experiments may not reflect the actual conditions in the field due to the lack of plant cover and the disturbed soil structure. To address this an experiment was performed using intact soil cores (7.5 cm depth), with pasture plants present, under controlled environmental conditions (20 °C, 8 h of light per day). The 15N flux method was used to investigate how antecedent soil moisture affected soil N2O production and consumption in a pasture soil after wetting with a nitrate (NO3−) solution. The results showed that the antecedent dry condition (25 % WFPS, Dp/Do = 0.1783) increased the magnitude of the N2O flux peak after the soil was wetted (75 % WFPS, Dp/Do = 0.006) when compared to antecedent wet conditions (50 % WFPS, Dp/Do = 0.0503). There were no differences in the denitrification and nitrification related functional gene abundances between the two antecedent conditions post-wetting, indicating that the effect was not regulated by microbial changes but by the intensity of the “Birch effect” induced by soil wetting. The N2O reduction related gene (nosZII) abundance decreased after wetting with the NO3− solution, indicating a suppression effect on N2O consumption from the NO3− applied that overrode the potential “Birch effect” on N2 emission. The results of the study indicate that rewetting of antecedent dry soil increase N2O emissions but not N2 emissions when the soil NO3− concentration is high.

Soil Cover Structure and Pasture Soil Properties in a Dry Steppe Zone under Conditions of Different Grazing Intensities

Soil Cover Structure and Pasture Soil Properties in a Dry Steppe Zone under Conditions of Different Grazing Intensities

Impacts of shelterbelt systems on pasture production and soil bacterial and fungal communities in agricultural fields

AbstractIntroductionShelterbelts, which provide protection for livestock and crops against severe weather conditions, have been recognised as important contributors to increased crop yields. Soil microorganisms play important roles in nutrient cycling, soil health and plant performance, thereby exerting significant influence on ecological services in terrestrial ecosystems. However, impacts of shelterbelts on soil microbial communities in pasture ecosystems remain poorly studied.Materials and MethodsHere, we assessed the effect of shelterbelts (composed of Eucalyptus and native shrubs) on the pasture and nutrient productivity as well as soil bacterial and fungal communities at four distances from the shelterbelts with two different heights in two fields during spring and summer by applying amplicon sequencing, physicochemical and nutritional value analyses.ResultsThe results showed that the shelterbelt height, distances from shelterbelts, seasons and their interactive effects substantially affected pasture yield, neutral detergent fibre, metabolisable energy and crude protein yields, but did not increase the pasture productivity in the rows adjacent to the shelterbelts. We also identified that the alpha diversity of bacteria and fungi did not significantly change across distances from the shelterbelts in both fields, but the community structure of soil bacteria and fungi was significantly influenced by distances from the shelterbelts. Interestingly, soil calcium (Ca) and shelterbelts were identified as top predictors of fungal community while soil pH and Ca was key drivers of bacterial community.ConclusionOur study provides novel knowledge in the impact of shelterbelts on pasture and nutritional production and soil microbial communities, which contributes to appropriate application and strategic management of the windbreak systems in agriculture production.

Sampling the spatial variability of grassland soil properties

The properties of grazed grassland soils are frequently degraded in tropical zones. This work aimed to review the literature on the theory and results of sampling and analysis of the spatial variability of pasture soil properties in the world and Ecuador. The methodology, results, and discussion of 15 articles on the subject, available in the following databases: Scopus, SciELO, ScienceDirect, Scimago Journal & Country Rank, Dialnet, and SpringerLink; and the respective theory of 5 books were reviewed. It was found that worldwide there are soil sampling works that evaluate the spatial variability of soil properties; at the national level, sampling does not consider this variability. It is essential to conduct research in Ecuador on the spatial variability of the properties of pasture soils, which will allow reliable decisions to be made for their management and conservation.

Isolation of saprophytic filamentous fungi from avian fecal samples and assessment of its predatory activity on coccidian oocysts

Fungal strains used in the biocontrol of animal gastrointestinal parasites have been mainly isolated from pasture soil, decaying organic matter, and feces from herbivores and carnivores. However, their isolation from birds and assessment of predatory activity against avian GI parasites has been scarce thus far. This research aimed to isolate filamentous fungi from avian fecal samples and evaluate their predatory activity against coccidia. A pool of 58 fecal samples from chickens, laying hens, and peacocks, previously collected between July 2020-April 2021, were used for isolation of filamentous fungi and assessment of their in vitro predatory activity against coccidian oocysts, using Water-Agar medium and coprocultures. The Willis-flotation technique was also performed to obtain concentrated suspensions of oocysts. A total of seven Mucor isolates was obtained, being the only fungal taxa identified, and all presented lytic activity against coccidia. Isolates FR3, QP2 and SJ1 had significant coccidiostatic efficacies (inhibition of sporulation) higher than 70%, while isolates FR1, QP2 and QP1 had coccidicidal efficacies (destruction of the oocysts) of 22%, 14% and 8%, respectively, after 14 days of incubation, being a gradual and time-dependent process. To our knowledge, this is the first report regarding the isolation of native predatory fungi from avian feces and demonstration of their lytic activity against coccidia.

Assessment of Changes in the Biological Activity of Mountain Meadow-Steppe Soils of Pastures of Different Stages of Digression in the Central Caucasus

The indicators of biological activity (humus content and reserves, microbial biomass carbon content and reserves, activity of hydrolase and oxidoreductase class enzymes) in the upper horizons (0–10 cm) of mountain meadow-steppe soils of the Central Caucasus (Kabardino-Balkaria) were determined at different stages of pasture digression (D1, D2, D3). It was found that the values of controlled soil parameters in conditions of weakly (D1) and moderately disturbed (D2) meadow phytocenoses did not significantly differ (t 1.97; P 0.05). Statistically significant decreases (t 2.95; P 0.05) in biological parameters were revealed in soils of severely disturbed meadow steppes (D3) compared with less damaged meadows (D1 and D2). Based on the totality of the studied indicators of biological activity, an integral indicator of the ecological and biological state of soils (IIEBSS) is calculated, reflecting the overall level of biological activity of the studied soils at different stages of digression of meadow-steppe communities. There was a decrease in the IIEBSS of moderately grazed (D2) and overgrazed (D3) meadows relative to the values of the conditional standard (D1) by 11and 45%, respectively. The obtained results of the biological state of mountain meadow-steppe soils are used for monitoring studies aimed at assessing the degree of change in the soil and vegetation cover of mountain pasture ecosystems.

Effective Proportion of Plantain (Plantago lanceolata L.) in Mixed Pastures for Botanical Stability and Mitigating Nitrous Oxide Emissions from Cow Urine Patches

Plantain (Plantago lanceolata L.) is recognised for its ability to improve summer feed productivity as well as mitigate nitrous oxide (N2O) emissions from grazed pastoral soils. This study aims to determine the proportion of plantain required in perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L.), or RWC, mixed swards to maintain yield stability and to quantify N2O emission reductions. The botanical composition was monitored when plantain was sown at different rates of 0%, 30%, 50% and 70% in RWC pastures under grazing by dairy cows over 2 grazing years. Urine from cows grazing RWC (6.15 g N L−1), 30% (5.40 g N L−1) and 50% (4.40 g N L−1) plantain mixed pastures was used to measure N2O emissions (n = 5) from the pastures of their origin and to assess the impact of the plantain rhizosphere on N2O emissions by applying the RWC urine to the 50% plantain mixed pasture, and vice versa, in late summer–autumn using the static chambers technique. After declining in spring, the plantain content recovered in early autumn and reached a peak of 40% in the 30% plantain mixed pasture and around 50% in the 50% and 70% plantain mixed pastures in winter. A lower N content in urine, and therefore a lower urine N-loading rate from cows grazing in the 50% plantain mixed pasture, resulted in 39% lower total N2O emissions compared to RWC urine treatment. In conclusion, 30% to 50% plantain in mixed pastures was stable throughout the 2 years, and it not only reduced the urinary N concentration in grazing cattle but also contributed to reduced N2O EFs.

Montado Mediterranean Ecosystem (Soil–Pasture–Tree and Animals): A Review of Monitoring Technologies and Grazing Systems

Montado is an agro-silvo-pastoral ecosystem characteristic of the south of Portugal and called Dehesa in Spain. Its four fundamental components—soil, pasture, trees, and animals—as well as the climate make Montado a highly complex ecosystem. This review article provides an overview of the state of the art of Montado from the point of view of the agro-silvo-pastoral ecosystem and the scientific work carried out in this context. Thus, the aim is: (i) to describe and characterize the Montado ecosystem, as an agro-silvo-pastoral system; (ii) to reveal experimental tests carried out, technologies used or with the potential to be used in the monitoring of Montado; (iii) to address other technologies, carried out in similar and different agro-silvo-pastoral ecosystems from south Portugal. This review consists of three chapters: (a) components of Montado and their interactions; (b) advanced technologies for monitoring Montado; (c) grazing systems. No review article is known to provide an overview of Montado. Thus, it is essential to carry out research on grazing and its effects on the soil and pasture in the Montado ecosystem.

A survey comparing regeneratively and conventionally managed pastures and farm management policies

A pasture and farm management survey was conducted on thirteen geographically paired regenerative and conventional beef and sheep farms in the upper North Island to identify differences in pasture attributes and management practices. Farms were paired by geographical location and livestock type. When compared to conventional pastures, regenerative pastures had a similar number of grass, legume and broadleaf species (averaging 4, 1 and 3 species respectively), three times as much legume (13 compared to 4% content) and 30% less perennial ryegrass in total DM (P<0.01) but a similar broadleaf content. There was no difference between pasture types in pre- or post-grazing covers. Compared to conventional pastures, soils sampled from regenerative pastures had a higher pH, and herbage had higher levels of calcium, boron, molybdenum (P<0.05) and a trend towards lower Olsen P values (P=0.052). There was a divergence between farm types in fertiliser policies, with regenerative farmers generally not using synthetic nitrogen (N) and phosphorus (P) products and applying a wider range of nutrients. Herbicides and pesticides were used across both farm types. Changes in pasture composition (i.e., less perennial ryegrass and more clover) and soil nutrient status were consistent with lower N and P inputs on regenerative farms.

Elevated and atmospheric‐level methane consumption by soil methanotrophs of three grasslands in China

AbstractBackgroundMethane (CH4) oxidation driven by soil aerobic methanotrophs demonstrates the capacity of grassland as a CH4 sink.MethodsIn this study, we compared the oxidation characteristics of atmospheric‐level and elevated concentration (10%) CH4 in a typical grassland (steppe) on the Loess Plateau, an alpine meadow (meadow) on the Qinghai‐Tibet Plateau, and an inland arid‐area artificial grassland (pasture) in northwest China and investigated the communities of active methanotrophs and their contribution to CH4 oxidation using DNA‐based stable‐isotope probing and Illumina Miseq sequencing.ResultsThe results showed that the oxidation of atmospheric CH4 only occurred in steppe and meadow soils where the USCγ group of methanotrophs was numerically dominant in the methanotroph community. Pasture soils, with their very low relative abundance of USCγ, did not show atmospheric CH4 oxidation. However, a DNA‐stable isotope probing experiment with 10% CH4 indicated that conventional CH4 oxidizers (Methylocaldum and Methylocystis) rather than USCγ communities assimilated significant amounts of 13CH4 for growth.ConclusionsThe CH4 oxidation mechanisms in the three experimental grassland soils varied significantly. The USCγ group may be obligate oligotrophic microorganisms or their growth requires specific unknown conditions.

In vitro effect of burned pasture soil on eggs and free-living larvae of ruminant gastrointestinal nematodes

Gastrointestinal nematodes are the most expensive agent of disease currently facing the livestock production industry. Spending the beginning of their life cycle as eggs and free-living larvae, nematodes are vulnerable to a multitude of external environmental factors. Fire is a naturally occurring force of nature that has both destructive and reconstructive effects on soil characteristics which nematode stages rely on for survival. The aim of this project was to evaluate in vitro the effect of burned pasture soil (200 °C and 500 °C) on the free-living stages of ruminant nematodes. We tested the effect of burned soil on the ability of eggs to hatch and produce infective larvae, and then tested survival of infective larvae within burned soil. Adding burned soil (500 °C) to larval cultures improved larval yield compared to larval cultures containing raw soil or soil burned at a lower heat (200 °C), and raw soil improved longer term survival of infective larvae. We were able to recover significantly more larvae from samples with low soil content either as raw or soil burned at 200 °C, when compared with samples with soil burned at 500 °C. This study has shown that the survival of gastrointestinal nematodes at the L3 stage is negatively impacted by the addition of soil burned at 500 °C. Although this temperature is closest to that of a medium intensity wildfire, which is a typically destructive process in agriculture, it reduces the number of infective GIN larvae available for animals to ingest. These experiments enable us to address in vitro if post-fire soil conditions alter the number of infective larvae available on pasture, and thus the infectivity of the pasture to livestock.

Factors for Conversion of the Content of Double-Stranded DNA to Carbon of Soil Microbial Biomass

The relationship between the concentration of soil DNA and microbial biomass, determined by the method of substrate-induced respiration was studied in a wide range of soils differing in particle size distribution, acidity, organic carbon content, microbial biomass, and type of human activity in antiquity and present time. Calcaric Leptosols and Leptic Phaeozems of medieval agricultural lands in the Central Caucasus, Stratozems of agricultural terraces of the late Middle Ages – Modern times in the middle mountain zone of the Eastern Caucasus, as well as Kashtanozems and Solonetzes with different grazing intensity in the dry steppe zone (Rostov region) were chosen as the key sites. It has been shown that the determination of soil dsDNA concentration is a reliable and simple method for determining microbial biomass in soils with a loam texture, organic carbon content less 2%, and microbial biomass less 700 µg C/g of dry soil. The conversion factor FDNA in such soils varied in a narrow range from 5.24 to 5.41. In soils with a high content of organic carbon, an increase of FDNA (6.56 and 10.56) was observed due to the presence of recalcitrant e-xtracellular DNA. Agristratified soil of sandy loam texture was characterized by a lower degree of preservation of dsDNA, which resulted in a decrease in the determined microbial biomass (FDNA = 4.22). A reduced conversion factor FDNA (4.78) was also found in the soils of pastures in the dry steppe zone, which confirms the known limitations of using the substrate-induced respiration method in alkaline soils. Human activity does not significantly affect the relationship between the amount of soil DNA and microbial biomass.

Soil Organic Carbon as Response to Reforestation Age and Land Use Changes: A Qualitative Approach to Ecosystem Services

The proper management of soil, in order to improve ecosystem services, requires knowledge of how different fractions of carbon respond to land use/land cover changes. This study aimed to evaluate the responses of total soil organic carbon, and its fractions, to reforestation age and land use changes in an Ultisol in the Posses catchment, a pilot area of the Brazilian program of Payment for Environmental Services, located in Southeastern Brazil. The study was conducted using field plots with various treatments, including native forest, old and young reforestation, well-managed pasture, subsistence farming, degraded pasture, and bare soil. Results showed that soil organic carbon increased with reforestation age and that original soil carbon stocks were restored after eight years of reforestation. Short-time pasture management increased the carbon pool by 10% compared to degraded pasture. The Carbon Management Index (CMI) was able to distinguish the effects of converting degraded pasture to either subsistence farming or bare soil. The CMI is a useful tool for determining the effects of land use/land cover changes, reforestation age, and native forest preservation on soil quality. Adequate management of soil fertilization is an immediate option for restoring the quality of Ultisols under degraded pastures in the Posses sub-basin.

Impacts of Rock Mineral and Traditional Phosphate Fertilizers on Mycorrhizal Communities in Pasture Plants.

Intensive fertilizer use can constrain contributions from soil biological processes in pastures, including those associated with arbuscular mycorrhizal (AM) fungi. We evaluated the effect of fertilizers of different P solubility on the colonization of the roots of two common pasture plants by a community of AM fungi in a pasture soil. The treatments were a rock mineral fertilizer, a chemical fertilizer and a microbial inoculant. Subterranean clover and annual ryegrass were grown in pots for 10 weeks. Both fertilizers reduced the proportion and length of roots colonized by naturally occurring AM fungi. However, by 10 weeks, there was a much greater length of mycorrhizal root for annual ryegrass than for subterranean clover. The relative abundance of mycorrhizal fungi in the families Glomeraceae and Acaulosporaceae in roots was not affected by the form of fertilizer, but diversity indices of AM fungi in roots were altered. The chemical fertilizer had a greater negative effect on AM fungal diversity indices in the annual ryegrass roots compared with the subterranean clover roots. The reduction in OTU richness of AM fungi with fertilizer application corresponded with reduced soil pH. Differential effects of P fertilizers on naturally occurring AM fungi in this agricultural soil have the potential to influence the efficacy of P fertilizer use and dominance of plant species in grasslands.

Simulation of degradation of pasture ecosystems of arid zone

New approaches to the study of succession dynamics are based on the original concept of system dynamics, which was used in the development of simulation models reflecting the dynamics of pasture ecosystems. The temporal dynamics of the soil and vegetation cover of the natural pastures of the Black Lands of Kalmykia reflects the degradation processes that are studied by simulation modeling. The processes of pasture degradation in the subarid belt of Southern Russia were described by ordinary differential equations. This concept is the basic one in the development of simulation models. The dynamics of changes in effective coatings for phytocenoses of pastures of Black Lands in the process of degradation was traced from the original pastures to complete desertification. Analytical solutions for various conditions of succession dynamics in the degradation of natural pasture lands are a convenient test for assessing the adequacy of simulation modeling. The initial time periods of space observations of effective coatings of phytocenoses were used to parametrize simulation models. The models are implemented in the AnyLogic simulation system. The model development process is based on visual programming using the graphical user interface. Information flows in the Anylogic environment are redistributed over time through a system of storage devices interconnected by an oriented graph of the model. A computational experiment demonstrating simulation results with different parameters was used for an indicative (qualitative) assessment of ecosystem sustainability. The results of analytical modeling using ordinary differential equations and simulation modeling showed a high identity. The study of the dynamics of pasture ecosystems using a variation experiment demonstrates the possibility of visual (cognitive) selection of the parameters of the model that determines the conditions of stationarity of pasture ecosystems. Studying the dynamics of successions of pasture phytocnoses by this method opens up new opportunities for solving problems of optimal use of biological resources and sustainability of pasture ecosystems.

A comparison of undisturbed soil cores with restructured columns using a new one‐step outflow model

AbstractUndisturbed soil cores may be best for studying field processes in the laboratory, but core variability can make them difficult to use. The goal of this study was to develop a method to make packed columns that have one‐step outflow curves similar to those of undisturbed cores. Undisturbed 15.2‐cm‐long cores and bulk soil were obtained from a sandy loam permanent pasture (Pasture) and a sandy clay loam uncultivated field (Springhill). Ordinary‐packed columns were made by compressing bulk soil to the average core bulk density, and layered columns were made by duplicating the average bulk densities of three core layers. Outflow was recorded from pressure head of −7.6 to −133 cm from newly packed columns and after drying to produce shrinkage cracks. A new outflow model that included initial water content (θi), final water content (θf), and time to reach 63.2% outflow (Τ) was fit to the data by adjusting a time exponent β (average r2 = 0.995). Column parameters were compared with cores by equivalence testing. Drying reduced θi and θf, possibly due to shrinkage cracks that increased drainable porosity. Columns of the Pasture soil had significantly greater Τ than natural cores, possibly due to lack of root‐formed pores in the columns. Overall, layered and dried columns were most similar to natural cores and less variable, and cumulative one‐step outflow curves from undisturbed cores and packed columns can be quantified with a simplified four‐parameter model. These methods and results may help make packed soil columns more representative of undisturbed soil.

Shifts in functional traits and interactions patterns of soil methane-cycling communities following forest-to-pasture conversion in the Amazon Basin.

Deforestation threatens the integrity of the Amazon biome and the ecosystem services it provides, including greenhouse gas mitigation. Forest-to-pasture conversion has been shown to alter the flux of methane gas (CH4 ) in Amazonian soils, driving a switch from acting as a sink to a source of atmospheric CH4 . This study aimed to better understand this phenomenon by investigating soil microbial metagenomes, focusing on the taxonomic and functional structure of methane-cycling communities. Metagenomic data from forest and pasture soils were combined with in situ CH4 fluxes and soil edaphic factors measurements and analysed using multivariate statistical approaches. We found a significantly higher abundance and diversity of methanogens in pasture soils. As inferred by co-occurrence networks, these microorganisms seem to be less interconnected within the soil microbiota in pasture soils. Metabolic traits were also different between land uses, with increased hydrogenotrophic and methylotrophic pathways of methanogenesis in pasture soils. Land-use change also induced shifts in taxonomic and functional traits of methanotrophs, with bacteria harboring genes encoding the soluble form of methane monooxygenase enzyme (sMMO) depleted in pasture soils. Redundancy analysis and multimodel inference revealed that the shift in methane-cycling communities was associated with high pH, organic matter, soil porosity, and micronutrients in pasture soils. These results comprehensively characterize the effect of forest-to-pasture conversion on the microbial communities driving the methane-cycling microorganisms in the Amazon rainforest, which will contribute to the efforts to preserve this important biome.

Changes in soil organic carbon fractions in abandoned croplands of Nepal

Cropland abandonment in Nepal is an emerging land use change that has significant impacts on ecosystem functions, particularly soil organic carbon (SOC) pools and stocks. Information relating to SOC is limited for the mountainous terrain of Nepal that is subject to either SOC loss from erosion or SOC accumulation from secondary succession after cropland is abandoned. The rate of cropland abandonment is accelerating in Nepal but the impact of the abandoned duration on SOC, fractions, and SOC stock has not yet been investigated. We used a space-for-time substitution approach to assess the impacts of abandonment on SOC concentrations, stocks and associated pools of carbon across abandoned cropland (<5, 5–10, and > 10 years) compared with forest, pasture, and currently cropped land. Soil samples were collected at four depth increments (0–10, 10–20, 20–40, 40–60 cm). The change in SOC and stock was found to be significantly higher in the surface (0–20 cm) compared with sub-surface soil (20–60 cm) and consistently decreased with increasing soil depth under all land uses. Change in soil nitrogen concentration followed a similar pattern to that of SOC at all land uses and depths. Among the SOC fractions, particulate organic carbon increased significantly by a greater proportion compared to mineral-associated organic carbon and dissolved organic carbon after 10 years of cropland abandonment. Abandoned cropland >10 years had a higher SOC stock (64.19 Mg ha−1) in the soil profile (0–60 cm) compared with cropped land (58.76 Mg ha−1) although it remained lower than forest (66.56 Mg ha−1) and pasture (66.60 Mg ha−1) soils. Although there was a decrease in the first five years, there was a significant accumulation of SOC, associated fractions, and SOC stock after ten years of abandonment and colonisation by vegetation indicating the inception of ecosystem regeneration in abandoned croplands in the mountainous region of Nepal.