scholarly journals Comparatives Study of Soil Organic Carbon (SOC) under Forest, Cultivated and Barren Land: A Case of Chovar Village, Kathmandu

2014 ◽  
Vol 14 (2) ◽  
pp. 103-108 ◽  
Author(s):  
S Bhandari ◽  
S Bam

The study was carried out in Chovar village of Kritipur Municipality, Kathmandu to compare the soil organic carbon (SOC) of three main land use types namely forest, agricultural and barren land and to show how land use and management are among the most important determinants of SOC stock. Stratified random sampling method was used for collecting soil samples. Walkley and Black method was applied for measuring SOC. Land use and soil depth both affected SOC stock significantly. Forest soil had higher SOC stock (98 t ha-1) as compared to agricultural land with 36.6 t ha-1 and barren land with 83.6 t ha-1. Similarly, the SOC in terms of CO22-1, 79.27 to 22.02 CO2-e ha-1 and 121.11 to 80.74 CO2-1 for 0- 20 cm to 40-60 cm soil depth, respectively. Bulk density (BD) was found less in forest soil compared to other lands at all depths, which showed negative correlation with SOC. The study showed a dire need to increase current soil C stocks which can be achieved through improvements in land use and management practices, particularly through conservation and restoration of degraded forests and soils.   DOI: http://dx.doi.org/10.3126/njst.v14i2.10422   Nepal Journal of Science and Technology Vol. 14, No. 2 (2013) 103-108

2020 ◽  
Vol 39 (2) ◽  
pp. 159-173
Author(s):  
Rastislav Skalský ◽  
Štefan Koco ◽  
Gabriela Barančíková ◽  
Zuzana Tarasovičová ◽  
Ján Halas ◽  
...  

AbstractSoil organic carbon (SOC) in agricultural land forms part of the global terrestrial carbon cycle and it affects atmospheric carbon dioxide balance. SOC is sensitive to local agricultural management practices that sum up into regional SOC storage dynamics. Understanding regional carbon emission and sequestration trends is, therefore, important in formulating and implementing climate change adaptation and mitigation policies. In this study, the estimation of SOC stock and regional storage dynamics in the Ondavská Vrchovina region (North-Eastern Slovakia) cropland and grassland topsoil between 1970 and 2013 was performed with the RothC model and gridded spatial data on weather, initial SOC stock and historical land cover and land use changes. Initial SOC stock in the 0.3-m topsoil layer was estimated at 38.4 t ha−1 in 1970. The 2013 simulated value was 49.2 t ha−1, and the 1993–2013 simulated SOC stock values were within the measured data range. The total SOC storage in the study area, cropland and grassland areas, was 4.21 Mt in 1970 and 5.16 Mt in 2013, and this 0.95 Mt net SOC gain was attributed to inter-conversions of cropland and grassland areas between 1970 and 2013, which caused different organic carbon inputs to the soil during the simulation period with a strong effect on SOC stock temporal dynamics.


Soil Research ◽  
2013 ◽  
Vol 51 (8) ◽  
pp. 657 ◽  
Author(s):  
F. C. Hoyle ◽  
M. D'Antuono ◽  
T. Overheu ◽  
D. V. Murphy

Assessment of the potential for soil carbon sequestration based on soil type, land use, and climate scenarios is crucial for determining which agricultural regions can be used to help mitigate increasing atmospheric CO2 concentrations. In semi-arid and Mediterranean-type environments, soil organic carbon (SOC) storage capacity is rarely achieved under dryland agricultural systems. We aimed to assess both actual (measured) and attainable (modelled) SOC stock values for the dryland agricultural production zone of Western Australia. We measured actual SOC storage (0–0.3 m) and known constraints to plant growth for a range of soils types (3–27% clay) and land uses (continuous cropping, mixed cropping, annual and perennial pastures) on the Albany sand plain in Western Australia (n = 261 sites), spanning a rainfall gradient of 421–747 mm. Average actual SOC stocks for land use–soil type combinations ranged from 33 to 128 t C/ha (0–0.3 m). Up to 89% of the variability in actual SOC stock was explained by soil depth, rainfall, land use, and soil type. The scenarios modelled with Roth-C predicted that attainable SOC values of 59–140 t C/ha (0–0.3 m) could be achieved within 100 years. This indicated an additional storage capacity of 5–45% (7–27 t C/ha) depending on the specific land use–soil type combination. However, actual SOC in the surface 0–0.1 m was 95 to >100% of modelled attainable SOC values, suggesting this soil depth was ‘saturated’. Our findings highlight that additional SOC storage capacity in this region is limited to the subsoil below 0.1 m. This has implications for management strategies to increase SOC sequestration in dryland agricultural systems, as current practices tend to concentrate organic matter near the soil surface.


Scientifica ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jun Shapkota ◽  
Gandhiv Kafle

Understanding distribution of soil organic carbon (SOC) in soil profile is important for assessing soil fertility and SOC stock because it varies with soils of different vegetation and land use types. In this context, the objective of this research is that it was conducted to determine key variance in the SOC stock in three different soil layers, 0–20 cm, 20–40 cm, and 40–60 cm of different vegetation covers of Shivapuri Nagarjun National Park of Kathmandu district, Nepal. Overall field measurement was based on standard national methods. We used the dichromate digestion method to analyse SOC concentrations. The highest SOC concentration (%) was recorded as 4.87% in 0–20 cm of oak forest and lowest 0.42% in 40–60 cm of Chir pine forest. Forest types (oak, upper mixed hardwood, lower mixed hardwood, and Chir pine) had SOC stock 149.62, 104.47, 62.5, and 50.85 t/ha, respectively, up to 60 cm depth. However, these values are significantly different ( p = 0.02 ) at 5% level of significance when comparing means between the forest types. The SOC stock was decreased with increased soil depth, though not significantly different at 5% level of significance. Further study with respect to different climate, soil, forest, and land use type is recommended.


Agropedology ◽  
2019 ◽  
Vol 26 (2) ◽  
Author(s):  
Shreyasi Gupta Choudhury ◽  
◽  
Tapati Banerjee ◽  
Krishnendu Das ◽  
A.K. Sahoo ◽  
...  

Characterization and classification of rice growing soils of rainfed region of West Bengal is having an utmost importance for developing optimal agricultural land use planning. In the context of ever increasing food demand under dwindling agricultural land availability, rainfed areas have got the attention for enhancing food grain production for the national food basket. Hence, in the present study, we made an effort to characterize six rice growing soils placed in six different landform situations (plateau top, dissected plateau, plateau fringe, undulating upland, alluvial plains and valley fill) and classify accordingly for resource inventory of Rajnagar block, Birbhum district, West Bengal. Results depicted that, rice is grown mainly in Alfisols and Inceptisols in this block with varying morphological and physico-chemical characteristics. The soils are moderately deep to very deep with sandy loam to clay loam surface texture. Soils of plateau top, dissected plateau, plateau fringe, undulating upland, alluvial plains and valley fill were classified as Typic Haplustalfs, Aeric Endoaqualfs, Typic Haplustalfs, Typic Haplustepts, Aeric Endoaquepts, Typic Haplustalfs, respectively. The double crop rice ecology (rice-mustard) showed significantly (P=0.05) higher surface soil organic carbon (SOC) stock in surface as compared to the other monocrop rice ecologies. Among all the landforms compared, soils of valley fill region had the highest surface SOC stock (14.5 Mg ha-1) followed by plains (10.4 Mg ha-1), plateau fringe (7.7 Mg ha-1), plateau top (8.1 Mg ha-1), dissected plateau (7.2 Mg ha-1) and upland (6.9 Mg ha-1). Significantly (P=0.05) higher total profile SOC stock suggested a better soil health in valley fill and plains as compared to other areas that enhances our understanding about the need of the implementation of carbon management based land use planning for higher future productivity of these soils under environmental sustenance.


2020 ◽  
Author(s):  
Yang Guo ◽  
Mohamed Abdalla ◽  
Mikk Espenberg ◽  
Astley Hastings ◽  
Paul Hallett ◽  
...  

<p>The main aim of this global review and systematic analysis was to investigate the impacts of previous land use system, climate zone and forest type and age on soil organic carbon (SOC), total nitrogen (TN) and total phosphorus (TP), in the different soil layers (0-20, 20-60 and 60-100 cm), following afforestation. We collected 85 publications on SOC, TN and TP stock changes, covering different countries and climate zones. The data were classified into groups depending on these investigated parameters and analyzed using R version 3.6.1. We found that afforestation significantly increased SOC and TN stocks in the 0-20 and 20-60 soil layers, with values of 45% and 44% for SOC, 30% and 22% for TN, respectively, but had no impact on TP stock. Previous land use systems had the largest influence on SOC, TN and TP stocks, with greater accumulations on barren land compared to cropland and grassland. Climate zone influenced SOC, TN and TP stocks, with significant accumulations in the moist than in the dry climate zone. Afforestation with broadleaf deciduous and broadleaf evergreen forests led to greater SOC, TN and TP accumulations in each soil layer throughout the investigated profile (0-100 cm), compared to coniferous forests. Afforestation for <20 years had significantly increased SOC and TN stocks only at the soil surface (0-20 cm) whilst afforestation for ≥ 20 years had significantly accumulated them up to 100 cm soil depth. TP stock did not change with the forest age, suggesting that it may become a limiting factor for carbon sequestration under the older-age forest. Following afforestation, the change of soil bulk density had inverse relationships with SOC or TN stocks changes but had no effect on TP stock change.</p>


2006 ◽  
Vol 26 (10) ◽  
pp. 3198-3203 ◽  
Author(s):  
Xinyu Zhang ◽  
Liding Chen ◽  
Bojie Fu ◽  
Qi Li ◽  
Xin Qi ◽  
...  

2018 ◽  
Vol 8 (1) ◽  
pp. 70
Author(s):  
Birhanu Biazin ◽  
Dong-Gill Kim ◽  
Tefera Mengistu

There has been an incessant conversion of natural forests to agricultural land uses such as farmlands, grasslands and parkland agro-forestry in Africa during the last century. This study investigated changes in soil organic carbon (SOC) and total nitrogen (TN) stocks following the conversion of a natural forest to coffee-based agro-forestry, grazing grassland and well-managed maize farm in a sub-humid tropical climate of Ethiopia. Soil samples (up to 1m depth) were taken from each of these four land use types. Taking the natural forest as a baseline and with duration of 35 years since land use conversion, the total SOC and TN stocks were not significantly different (P > 0.05) among the different land use types when the entire 1m soil depth was considered. However, in the upper 0-10cm soil depth, the SOC and TN stocks were significantly higher (P < 0.05) in the natural forest than the agricultural land use types. There were different patterns of SOC and TN distributions along the soil depths for the different land use types. The SOC stocks decreased with depth in natural forest, but did not show any increasing or decreasing trends in maize farm, grazing grassland, and coffee-based agroforestry. The results of this study revealed that the negative effects of converting natural forests to agricultural land use types on SOC and TN can be prevented through appropriate land management practices in cultivated and grazing lands and use of proper agroforestry practices in a sub-humid tropical climate.


2020 ◽  
Author(s):  
Sergio Saia ◽  
Calogero Schillaci ◽  
Aldo Lipani ◽  
Alessia Perego ◽  
Marco Acutis

&lt;p&gt;Mediterranean areas are vulnerable and at high risk of desertification, although harboring high fractions of the global biodiversity. Resilience of these (agro)ecosystem strongly relies on soil preservation, and thus the reduction of both the sediment and soil organic carbon (SOC) losses. However, SOC dynamic is understudied in the Mediterranean areas, especially in the arid and semiarid regions &lt;strong&gt;[1]&lt;/strong&gt;.&lt;/p&gt;&lt;p&gt;Here we are summarizing the known and unknown of the SOC modelling in a highly variable Mediterranean area, namely Sicily (southern Italy). In addition, we highlight main research needs to increase the reliability of the estimation of the SOC change in time.&lt;/p&gt;&lt;p&gt;A total of 6674 soil samples were taken in various sampling campaigns from the 1993 to the 2008 from various depths (of which only 20% with soil bulk density [SBD] information) from both agricultural and forest lands on a 25,711-km&lt;sup&gt;2&lt;/sup&gt; area &lt;strong&gt;[2]&lt;/strong&gt;. Such database was used for SOC modelling through various procedures including classification and regression trees (CARTs) and Least Absolute Shrinkage and Selection Operator (LASSO) &lt;strong&gt;[3-5]&lt;/strong&gt;.&lt;/p&gt;&lt;p&gt;Modelling SOC stock estimated with an already developed pedotransfer (R&lt;sup&gt;2&lt;/sup&gt; = 0,3) function for SBD consisted in a high uncertainty, with a ratio between the model mean absolute error and the modelled 90&lt;sup&gt;th&lt;/sup&gt; percentile higher than 26.9%, suggesting that SBD information or its reliable prediction is a prerequisite for SOC stock modelling in these areas, especially in agricultural land. In addition, taking into account the sampling campaign almost doubled the r squared of the CART models, which on average outcompeted the kriging and LASSO methods for the prediction certainty.&lt;/p&gt;&lt;p&gt;When modelling the time-variation of the SOC concentration through the use of non-paired samples &lt;strong&gt;[5]&lt;/strong&gt;, the closer of which was few km apart, a mean SOC variation was highlighted, and the model yielded high pseudo-R&lt;sup&gt;2&lt;/sup&gt; (0.63&amp;#8211;0.69) and low uncertainty (s.d. &lt; 0.76 g C kg&lt;sup&gt;&amp;#8722;1&lt;/sup&gt;). However, these s.d. can be used only to highlight strong variations at a relatively low resolution (i.e. 1-km), especially if data are not collected with the same sampling scheme. The variation found in the aforementioned work &lt;strong&gt;[5]&lt;/strong&gt; likely depended on a change of both the sampling scheme and land use rather than an accumulation or loss of SOC in a given land use.&lt;/p&gt;&lt;p&gt;Thus, measuring SOC concentration and SBD in time-paired sites appears as a prerequisite to detect a SOC change in a given land use, especially if taking into account that the most important SOC predictors throughout the experiments were rainfall and temperatures and climate change is likely to differentially affect each site. To overcome such a lack, a time paired-sampling was performed in 2017 in 30 sites in the arable land, providing evidence that the increases estimated from the 1993 to 2008 were not evident when resampling the 10% of the 1993&amp;#8217;s sites in field with continuous arable land use.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;Reference: &lt;strong&gt;[1]&lt;/strong&gt; Schillaci et al. DOI: 10.3301/ROL.2018.68; &lt;strong&gt;[2]&lt;/strong&gt; Schillaci et al. DOI: 10.1016/j.catena.2018.12.015; &lt;strong&gt;[3]&lt;/strong&gt; Veronesi and Schillaci DOI: 10.1016/j.ecolind.2019.02.026; &lt;strong&gt;[4]&lt;/strong&gt; Lombardo et al. DOI: 10.1016/j.geoderma.2017.12.011; &lt;strong&gt;[5]&lt;/strong&gt; Schillaci et al. DOI: 10.1016/j.scitotenv.2017.05.239&lt;/p&gt;


2010 ◽  
Vol 73 (1) ◽  
pp. 70-76 ◽  
Author(s):  
Yafeng Wang ◽  
Bojie Fu ◽  
Yihe Lü ◽  
Chengjun Song ◽  
Yong Luan

Soil organic carbon (SOC) is one of the key components for assessing soil quality. Meanwhile, the changes in the stocks SOC may have large potential impact on global climate. It is increasingly important to estimate the SOC stock precisely and to investigate its variability. In this study, Yangjuangou watershed was selected to investigate the SOC distribution under different land uses. We found that SOC concentration decreased with increasing soil depth under all land uses and was significantly different across the vertical soil profile (P < 0.01). However, considering effect of land use on SOC, it is only significant (P < 0.01) in the topsoil (0–5 cm) layer. This indicated that land use has a large effect on the stocks of SOC in the surface soil. The stratification ratio of SOC > 1.2 may mean that soil quality is improving. The order of the SOC density (0–30 cm) under different land uses is forestland > orchard land > grassland > immature forestland > terraced cropland. The SOC stock is found to be as large as 2.67 × 10 t (0–30 cm) in this watershed. Considering time effect of restoration, the slope cropland just abandoned is more efficient for SOC accumulation than trees planted in the semi-arid hilly loess area.


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