Variation in Soil Organic Carbon under Different Forest Types in Shivapuri Nagarjun National Park, Nepal

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.

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

Nepal Journal of Science and Technology ◽

10.3126/njst.v14i2.10422 ◽

2014 ◽

Vol 14 (2) ◽

pp. 103-108 ◽

Cited By ~ 5

Author(s):

S Bhandari ◽

S Bam

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Forest Soil ◽

Agricultural Land ◽

Soil Depth ◽

Barren Land ◽

C Stocks ◽

Soc Stock ◽

Land Use And Management

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

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Spatial variability of soil organic carbon in a typical watershed in the source area of the middle Dan River, China

Soil Research ◽

10.1071/sr12327 ◽

2013 ◽

Vol 51 (1) ◽

pp. 41 ◽

Cited By ~ 13

Author(s):

Guo-Ce Xu ◽

Zhan-Bin Li ◽

Peng Li ◽

Ke-Xin Lu ◽

Yun Wang

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Spatial Variability ◽

Spatial Heterogeneity ◽

Spatial Variation ◽

Soil Depth ◽

Source Area ◽

Soil Layers ◽

Land Use Types

Soil organic carbon (SOC) plays an important role in maintaining and improving soil fertility and quality, in addition to mitigating climate change. Understanding SOC spatial variability is fundamental for describing soil resources and predicting SOC. In this study, SOC content and SOC mass were estimated based on a soil survey of a small watershed in the Dan River, China. The spatial heterogeneity of SOC distribution and the impacts of land-use types, elevation, slope, and aspect on SOC were also assessed. Field sampling was carried out based on a 100 m by 100 m grid system overlaid on the topographic map of the study area, and samples were collected in three soil layers to a depth of 40 cm. In total, 222 sites were sampled and 629 soil samples were collected. The results showed that classical kriging could successfully interpolate SOC content in the watershed. Contents of SOC showed strong spatial heterogeneity based on the values of the coefficient of variation and the nugget ratio, and this was attributed largely to the type of land use. The range of the semi-variograms increased with increasing soil depth. The SOC content in the soil profile decreased as soil depth increased, and there were significant (P < 0.01) differences among the three soil layers. Land use had a great impact on the SOC content. ANOVA indicated that the spatial variation of SOC contents under different land use types was significant (P < 0.05). The SOC mass of different land-use types followed the order grassland > forestland > cropland. Mean SOC masses of grassland, forestland, and cropland at a depth of 0–40 cm were 5.87, 5.61, and 5.07 kg m–2, respectively. The spatial variation of SOC masses under different land-use types was significant (P < 0.05). ANOVA also showed significant (P < 0.05) impact of aspect on SOC mass in soil at 0–40 cm. Soil bulk density played an important role in the assessment of SOC mass. In conclusion, carbon in soils in the source area of the middle Dan River would increase with conversion from agricultural land to forest or grassland.

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Capacity for increasing soil organic carbon stocks in dryland agricultural systems

Soil Research ◽

10.1071/sr12373 ◽

2013 ◽

Vol 51 (8) ◽

pp. 657 ◽

Cited By ~ 39

Author(s):

F. C. Hoyle ◽

M. D'Antuono ◽

T. Overheu ◽

D. V. Murphy

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Western Australia ◽

Soil Type ◽

Storage Capacity ◽

Soil Depth ◽

Continuous Cropping ◽

Agricultural Systems ◽

Soc Stock

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.

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Land Use Types and Geomorphic Settings Reflected in Soil Organic Carbon Distribution at the Scale of Watershed

Sustainability ◽

10.3390/su10103490 ◽

2018 ◽

Vol 10 (10) ◽

pp. 3490 ◽

Cited By ~ 4

Author(s):

Ye Yuan ◽

Xueyi Shi ◽

Zhongqiu Zhao

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Spatial Pattern ◽

North China ◽

Correlation Method ◽

Terrestrial Ecosystem ◽

Soil Productivity ◽

Land Use Types ◽

Soc Stock

Soil organic carbon (SOC) is vital to soil ecosystem function and it plays a key role in carbon cycling in the terrestrial ecosystem. The spatial pattern of SOC stock (SOCs) is affected by specific geomorphic settings and land-use types at the scale of watershed. Nevertheless, the distribution of SOCs with fluvial landform regimes and land use types was not sufficiently elucidated in the semi-humid riparian ecosystem in north China. In this study, 103 soil plots were sampled and spatial auto-correlation method was adopted to detect the spatial pattern of SOCs in the Changhe watershed that was located at the boundary of the Loess Plateau and the Taihang Mountains. The results showed that SOCs in the Changhe watershed varied from 18.03 Mg ha−1 to 21.51 Mg ha−1 and it was in the order: grassland > forestland > cropland > construction land. SOCs varied with geomorphic settings, among which, the altitude exerted more influence on the distribution of SOCs than the aspect and the slope. In terms of the spatial pattern of SOCs, 17 plots with higher SOCs collectively distributed in the west of the watershed and that with lower SOCs (19 plots) concentrated in the midlands. This indicated that the upland had higher SOCs while the lowland had lower values. Overall, land use type and geomorphic settings (especially the altitude) should be considered when estimating the SOC sequestration in warmer and wetter watershed in north China. With regard to the implications for land use management, reforestation could elevate the SOCs. Moreover, no-tillage and returning crop straw to cultivated soils could be efficient approaches to elevate soil carbon sequestration and soil productivity.

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Effects of Different Land Use Types Managed By Smallholder Farmers on Soil Properties in Central Ethiopia

10.21203/rs.3.rs-587450/v1 ◽

2021 ◽

Author(s):

Getahun Haile ◽

Mulugeta Lemenih ◽

Fisseha Itanna ◽

Beyene Teklu ◽

Getachew Agegnehu

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Properties ◽

Total Nitrogen ◽

Soil Depth ◽

Chemical Properties ◽

Grazing Land ◽

Land Use Types ◽

And Chemical Properties

Abstract Background Aim: Land use change causes a remarkable change in soil properties. The nature of change depends on multiple factors such as soil type, type and intensity of land use, climate, and the like. This study investigated the variation in soil physicochemical properties across five common land use practices i.e., enset system, farmland, and grazing-land (closed and open), and Eucalyptus woodlots practiced on originally same soil type and comparable topographic and climatic settings.Methods: A total of 105 disturbed and undisturbed soil samples [5 treatments (land use types) *7 replications (household)* 3 soil depth layers: 0–15cm, 15–30 cm, 30–45cm] were collected for selected soil chemical and physical analyses. Standard soil analytical procedures were followed in carrying out soil analysis. To meet the assumptions of normal distribution and homogeneity of variances, soil data on available phosphors were log-transformed before statistical analysis was undertaken and reported after back transformation. Two way analysis of variable were used to investigate the effects of land use and soil depth and their interaction on soil properties and when the analysis showed a significant difference (p <0.05) among land use and soil depth men separation were made using Turkey’s pairwise comparisons.Results: There were significant differences in physical and chemical properties of soil across land use and soil depth categories. Enset system had significantly higher pH, available phosphorus (P), exchangeable potassium (K+), soil organic carbon (SOC), and total nitrogen (TN) and their stocks than other land use types. Enset fields had higher SOC (78.4%) and soil TN (75%), and SOC and TN stocks of (66%) and (58%), respectively than cereal farmland. This study had also revealed a less expected finding of higher soil organic carbon and total nitrogen under Eucalyptus wood than farm land. Soil carbon and total nitrogen stocks showed a decreasing trend of enset system> closed grazing-land > eucalyptus woodlot > open grazing-land > farmland 0-45cm.Conclusion: Overall, some land use systems (e. g. enset agroforestry) improve the soil biophysical and chemical properties, while others such as cereal production degrade the soil. Hence appropriate land and soil management intervention should be promptly adapted to mitigating the continuous loss of nutrient from the dominantly practiced cereal farm land through maintaining crop residues, manure, crop rotation and scaling up agro-forestry system.

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Interactive effects of land use and soil erosion on soil organic carbon in the dry-hot valley region of southern China

10.5194/egusphere-egu21-2556 ◽

2021 ◽

Author(s):

Yawen Li ◽

Xingwu Duan ◽

Ya Li ◽

Yuxiang Li ◽

Lanlan Zhang

Keyword(s):

Land Use ◽

Soil Erosion ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Southern China ◽

Soil Depth ◽

Erosion Rates ◽

Land Use Types ◽

Study Results ◽

Effects Of Land Use

Changes in land use can result in soil erosion and the loss of soil organic carbon (SOC). However, the individual contribution of different land use types on SOC variability as well as the combined impacts of land use and soil erosion are still unclear. The aims of the present study were to: (1) evaluate soil erosion and SOC contents under different land use types, (2) identify the influences of soil depth and land use on SOC content, and (3) determine the contribution of land use and soil erosion on SOC variability. We assessed the SOC and total soil nitrogen (TSN) contents under three types of land use in the dry-hot valley in southern China. Caesium-137 (137Cs) and excess lead-210 (210Pbex) contents were also measured to determine soil-erosion rates. Land use was found to significantly affect soil erosion, and erosion rates were higher in orchard land (OL) relative to farmland (FL), which is in contrast with previous study results. SOC and TSN contents varied significantly between the three land use types, with highest values in forest land (FRL) and lowest values in OL. SOC was found to decrease with decreasing soil depth; the highest rate of reduction occurred in the reference site (RS), followed by FRL and FL. The interaction between soil erosion and land use significantly impacted SOC in the soil surface layer (0&#8211;12 cm); the direct impact of soil erosion accounted for 1.5% of the SOC variability, and the direct or indirect effects of land use accounted for the remainder of the variability. SOC content in deep soil was mainly affected by factors related to land uses (89.0%). This quantitative study furthers our understanding on the interactive mechanisms of land use and soil erosion on changes in soil organic carbon.

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Comparative assessment of profile storage of soil organic carbon and total nitrogen in forest and grassland in Jajarkot, Nepal

Journal of Agriculture and Natural Resources ◽

10.3126/janr.v3i2.32505 ◽

2020 ◽

Vol 3 (2) ◽

pp. 184-192

Author(s):

Mamata Sharma ◽

Gandhiv Kafle

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Sample ◽

Total Nitrogen ◽

Soil Profile ◽

Soil Depth ◽

C:N Ratio ◽

Soil Layer ◽

Soc Stock ◽

Level Of Significance

Understanding distribution of soil organic carbon and nitrogen in soil profile is important for assessing soil fertility and soil carbon dynamics. However, little is known about their distribution in soil depth below 30cm in Nepal. In this context, this research was carried out in 2019 to determine the Soil Organic Carbon (SOC) and Total Nitrogen (TN) in 0-10 cm, 11-30 cm and 31-60 cm depths of soil profile at forest and grassland in Kotila community forest, Jajarkot, Nepal. Overall field measurement was based on national standard protocols. Three replicates of soil pit from forest and grassland were dug for soil sample collection. Approximately 100 g soil sample from each soil layer was collected and taken to laboratory for SOC analysis. Separate soil samples, one sample from each soil layer were collected with the help of a metal soil corer having volume 245.22cm3 to quantify bulk density. Forest has 25.42 ton/ha SOC stock and 3.28 ton/ha TN stock up to 60 cm soil depth. Likewise, Grassland has 21.19 ton/ha SOC stock and 3.14 ton/ha TN stock up to 60cm soil depth. However, these values are not significantly different at 5 % level of significance. The SOC and TN were decreased with increased soil depths, though not significantly different at 5 % level of significance. The C:N ratio was found higher in forest than grassland. It is concluded that SOC and TN do not vary significantly between forest and grassland. Topsoil contains more SOC, TN, and C:N ratio, so the management practices should focus on maintaining inputs of soil organic matter in the forest and grassland.

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Soil Organic Carbon and Nitrogen Stocks Following Land Use Changes in a Sub-Humid Climate

Environment and Natural Resources Research ◽

10.5539/enrr.v8n1p70 ◽

2018 ◽

Vol 8 (1) ◽

pp. 70

Author(s):

Birhanu Biazin ◽

Dong-Gill Kim ◽

Tefera Mengistu

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Agricultural Land ◽

Soil Depth ◽

Natural Forest ◽

Agricultural Land Use ◽

Natural Forests ◽

Land Use Types ◽

Agro Forestry

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.

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Local-Scale Spatial Variability of Soil Organic Carbon and its Stock in the Hilly Area of the Loess Plateau, China

Quaternary Research ◽

10.1016/j.yqres.2008.11.006 ◽

2010 ◽

Vol 73 (1) ◽

pp. 70-76 ◽

Cited By ~ 75

Author(s):

Yafeng Wang ◽

Bojie Fu ◽

Yihe Lü ◽

Chengjun Song ◽

Yong Luan

Keyword(s):

Land Use ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Quality ◽

Soil Depth ◽

Global Climate ◽

Land Uses ◽

Loess Area ◽

Soc Stock ◽

Soc Density

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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