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

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.

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

Scientifica ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jun Shapkota ◽  
Gandhiv Kafle
Keyword(s):  
Land Use ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
National Park ◽  
Soil Depth ◽  
Forest Types ◽  
Land Use Types ◽  
Soc Stock ◽  
Chir Pine ◽  
Level Of Significance

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.

scholarly journals Soil organic carbon stocks are systematically overestimated by misuse of the parameters bulk density and stone content

2016 ◽  
Author(s):  
Christopher Poeplau ◽  
Cora Vos ◽  
Axel Don
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Bulk Density ◽  
Agricultural Soils ◽  
Soil Layer ◽  
Future Studies ◽  
Soil Organic Carbon Stocks ◽  
Soc Stock ◽  
The Mean ◽  
Soc Stocks

Abstract. Estimation of soil organic carbon (SOC) stocks requires estimates of the carbon content, bulk density, stone content and depth of a respective soil layer. However, different application of these parameters could introduce a considerable bias. Here, we explain why three out of four frequently applied methods overestimate SOC stocks. In stone rich soils (> 30 Vol. %), SOC stocks could be overestimated by more than 100 %, as revealed by using German Agricultural Soil Inventory data. Due to relatively low stone content, the mean systematic overestimation for German agricultural soils was 2.1–10.1 % for three different commonly used equations. The equation ensemble as re-formulated here might help to unify SOC stock determination and avoid overestimation in future studies.

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
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

Effects of conversion from vineyard to tree plantation on humus forms, soil organic carbon stock and other soil properties

2020 ◽  
Author(s):  
Chiara Ferré ◽  
Gianni Facciotto ◽  
Sara Bergante ◽  
Roberto Comolli
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Properties ◽  
Soil Texture ◽  
C:N Ratio ◽  
Tree Plantation ◽  
Humus Forms ◽  
Organic Horizons ◽  
Soc Stock ◽  
The Impact

<p>We explored the effects of conversion from vineyard to tree plantation on humus forms, soil organic carbon (SOC) stocks and other soil properties by sampling paired plots in a hilly area of Monferrato (Piedmont, Italy).</p><p>The study area is located at Rosignano Monferrato (AL) and includes a vineyard (VY) and a nearby 30-years-old tree plantation (TP) for wood production that replaced an existing vineyard, where eight poplar clones were consociated with other timber species (wild cherry, European ash, manna ash, deodar cedar). The area under study covers 3 ha and extends along a slighty-wavy slope with an average gradient of 15%; according to the WRB classification, soils are Calcaric Cambisols (Loamic).</p><p>The impact of land use change on soil properties was evaluated considering the spatial variability of soil characteristics, testing for autocorrelation among the model residuals. Soil sampling was performed from 3 layers (0-10 cm, 10-40 cm and 40-70 cm) at 61 and 69 points in the VY and the TP respectively, to characterize soil pH in water, organic carbon content and SOC stock, C:N ratio, soil texture and total carbonates. The common pedological origin of soils within the study area was verified and confirmed by comparability of soil texture and carbonates content of the deeper layer.</p><p>At TP the humus forms were described and classified; the organic horizons were sampled and analyzed for OC content determination.</p><p>Statistical analyses showed significant (p-value < 0.05) differences for all the investigated layers between the considered land uses with regard to pH, SOC stock and C:N ratio.</p><p>Our study provided evidence that: (1) the conversion from vineyard to tree plantation resulted in the appearance of organic horizons: the main humus forms in TP were Mull and Amphi; (2) 30 years of tree plantation strongly modified SOC stock, resulting in an increase of 26% in the first 70 cm, which became 42% if the organic layers were included; (2) soil acidification (pH difference of 0.4) and change in SOC type (C:N increase of 1) were also observed in TP compared to VY; and (3) the spatial distribution of soil properties in the VY were affected by erosive and depositional dynamics unlike the TP where vegetation counterbalance erosion.</p>

The chemical and physical stability soil organic carbon in the top 1 m of the soil profile under different land uses in the UK

2020 ◽  
Author(s):  
Dedy Antony ◽  
Jo Clark ◽  
Chris Collins ◽  
Tom Sizmur
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Profile ◽  
Soil Depth ◽  
Physical Stability ◽  
Silty Clay ◽  
Land Uses ◽  
Total N

<p>Soils are the largest terrestrial pool of organic carbon and it is now known that as much as 50% of soil organic carbon (SOC) can be stored below 30 cm. Therefore, knowledge of the mechanisms by which soil organic carbon is stabilised at depth and how land use affects this is important.</p><p>This study aimed to characterise topsoil and subsoil SOC and other soil properties under different land uses to determine the SOC stabilisation mechanisms and the degree to which SOC is vulnerable to decomposition. Samples were collected under three different land uses: arable, grassland and deciduous woodland on a silty-clay loam soil and analysed for TOC, pH, C/N ratio and texture down the first one metre of the soil profile. Soil organic matter (SOM) physical fractionation and the extent of fresh mineral surfaces were also analysed to elucidate SOM stabilisation processes.</p><p>Results showed that soil texture was similar among land uses and tended to become more fine down the soil profile, but pH did not significantly change with soil depth. Total C, total N and C/N ratio decreased down the soil profile and were affected by land use in the order woodland > grassland > arable. SOM fractionation revealed that the free particulate organic matter (fPOM) fraction was significantly greater in both the topsoil and subsoil under woodland than under grassland or arable. The mineral associated OC (MinOC) fraction was proportionally greater in the subsoil compared to topsoil under all land uses: arable > grassland > woodland. Clay, Fe and Mn availability play a significant role (R<sup>2</sup>=0.87) in organic carbon storage in the top 1 m of the soil profile.</p><p>It is evidently clear from the findings that land use change has a significant effect on the dynamics of the SOC pool at depth, related to litter inputs to the system.</p>

scholarly journals Impacts of Climate and Land Cover on Soil Organic Carbon in the Eastern Qilian Mountains, China

2019 ◽  
Vol 11 (20) ◽  
pp. 5790
Author(s):  
Junju Zhou ◽  
Dongxiang Xue ◽  
Li Lei ◽  
Lanying Wang ◽  
Guoshuang Zhong ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Land Cover ◽  
Soil Depth ◽  
Soil Layer ◽  
Qilian Mountains ◽  
Monthly Precipitation ◽  
Land Cover Types ◽  
The Mean

Soil, as the largest organic carbon pool of terrestrial ecosystem, plays a significant role in regulating the global carbon cycle, atmospheric carbon dioxide (CO2) levels, and global climate change. It is of great significance to scientifically understand the change rule and influence mechanism of soil organic carbon (SOC) to further understand the "source–sink" transformation of SOC and its influence on climate change. In this paper, the spatiotemporal distribution characteristics and influencing mechanism of SOC were analyzed by means of field investigation and laboratory analysis and the measured data in the Eastern Qilian Mountains. The results showed that the average SOC content of 0–50 cm was 35.74 ± 4.15 g/kg and the range of coefficients of variation (CV) between 48.84% and 75.84%, which suggested that the SOC content exhibited moderate heterogeneity at each soil layer of the Eastern Qilian Mountains. In four land cover types, the SOC content of forestland was the highest, followed by alpine meadow, grassland, and wilderness, which presented surface enrichment, and there was a decreasing trend with the soil depth. From the perspective of seasonal dynamics, there was a uniform pattern of SOC content in different land cover types, shown to be the highest in winter, followed by autumn, spring, and summer, and with the biggest difference between winter and summer appearing in the surface layer. At the same time, our study suggested that the SOC content of different land cover types was closely related to aboveground biomass and negatively related to both the mean monthly temperature and the mean monthly precipitation. Therefore, the distribution and variation of SOC was the result of a combination of climate, vegetation, and other factors.

Yield and nitrogen use efficiency in wheat, and soil fertility status as influenced by substitution of rice with pigeon pea in a rice - wheat cropping system

2006 ◽  
Vol 46 (9) ◽  
pp. 1185 ◽  
Author(s):  
V. K. Singh ◽  
B. S. Dwivedi
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Bulk Density ◽  
Nitrogen Use Efficiency ◽  
Soil Profile ◽  
Soil Depth ◽  
Pigeon Pea ◽  
Grain Legume ◽  
Nitrogen Use ◽  
Use Efficiency

Rice–wheat cropping systems managed on 10 million ha in the Indo-Gangetic Plain region (IGPR) of India are the most important production systems for national food security. Recent reports, however, indicate that the system is under production fatigue and the growth rates of rice and wheat have started declining. We, therefore, conducted field experiments at Modipuram, Meerut, India, for 3 consecutive years (1998–99 to 2000–01), to study the conservation of soil organic carbon, improvement in nitrogen use efficiency and increase in system yields through inclusion of a grain legume (pigeon pea) in place of rice. The wheat yields following pigeon pea crops were significantly (P<0.05) greater than those following rice crops during 1999–2000 and 2000–01, but not during 1998–99. The economic optimum doses of fertiliser N for wheat in the pigeon pea–wheat system were smaller (128–133 kg N/ha) than those in the rice–wheat system (139–173 kg N/ha), owing to increased N supply, greater N use efficiencies and a better crop growth environment in the pigeon pea–wheat system. The post-wheat harvest nitrate-N (NO3-N) at 90–105 cm soil depth in plots fertilised with 120 or 180 kg N/ha was greater for the rice–wheat system (6.5–8.1 mg/kg) than for the pigeon pea–wheat system (5.8–6.0 mg/kg), suggesting that inclusion of pigeon pea may help to minimise NO3-N leaching to deeper soil profile layers. In plots of pigeon pea, soil organic carbon at 0–15 cm and 15–30 cm soil depths was increased at the end of the experiment compared with the initial organic carbon content. With continuous rice–wheat cropping, the bulk density of soil increased over the initial bulk density, at different soil profile depths in general, and at 30–45 cm soil depth in particular. Inclusion of pigeon pea in the system maintained soil bulk density at its initial level, and thus eliminated sub-surface soil compaction. Despite these advantages of pigeon pea over rice as a preceding crop to wheat, permanent substitution of rice with pigeon pea in rice–wheat system is unlikely, because rice is a staple foodgrain crop in India. Nonetheless, decline in wheat productivity owing to puddling-induced soil constraints that arise on continuous rice–wheat systems could be minimised by introduction of pigeon pea into the system at longer time intervals.

Spatial variability of soil organic carbon in the West Liao River Basin

2018 ◽  
Vol 64 (1-4) ◽  
pp. 25-34
Author(s):  
Yong-hua Zhu ◽  
Sheng Zhang ◽  
Biao Sun ◽  
Xiao-kang Xi ◽  
Yu Liu ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Spatial Variability ◽  
Soil Depth ◽  
Soil Layer ◽  
Kriging Interpolation ◽  
Spherical Models ◽  
Basin Edge ◽  
Depth Increase

Quantification of the pattern and spatial distribution of soil organic carbon (SOC) is essential to comprehending many eco-hydrological processes. To obtain a better understanding of the spatial variability of SOC in a typical farming-pastoral zone, 270 soil samples were collected at 45 sampling sites from every 20 cm soil layer. Semi-variance function theory and ordinary Kriging interpolation were applied to identify the spatial variability of SOC. The results showed that SOC in the area was relatively low and decreased with depth and from the basin edge to the centre with a measured mean content of 0.07–0.65 g/kg. The strongest variability in the zone in the top soil layer (0–40 cm) was in the centre part of the zone, which was supposed to be the most concentrated area of human activities in the zone. As soil depth increase, the degree of variation of SOC decreased. Gaussian, exponential, and spherical models were suggested to successfully simulate SOC in different soil depth zones. The spatial distribution of SOC showed strong variability in the same soil depth zone, with a nugget to sill ratio of less than 14% and a range of 30–160 km.

scholarly journals The Vertical Differences in the Change Rates and Controlling Factors of Soil Organic Carbon and Total Nitrogen along Vegetation Restoration in a Subtropical Area of China

2020 ◽  
Vol 12 (16) ◽  
pp. 6443
Author(s):  
Zhiwei Cao ◽  
Xi Fang ◽  
Wenhua Xiang ◽  
Pifeng Lei ◽  
Changhui Peng
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Total Nitrogen ◽  
Surface Soil ◽  
Lower Layer ◽  
Soil Layer ◽  
Vegetation Restoration ◽  
Soil Factors ◽  
Deep Soil ◽  
Soil Layers

The study was to investigate the change patterns of soil organic carbon (SOC), total nitrogen (TN), and soil C/N (C/N) in each soil sublayer along vegetation restoration in subtropical China. We collected soil samples in four typical plant communities along a restoration chronosequence. The soil physicochemical properties, fine root, and litter biomass were measured. Our results showed the proportion of SOC stocks (Cs) and TN stocks (Ns) in 20–30 and 30–40 cm soil layers increased, whereas that in 0–10 and 10–20 cm soil layers decreased. Different but well-constrained C/N was found among four restoration stages in each soil sublayer. The effect of soil factors was greater on the deep soil than the surface soil, while the effect of vegetation factors was just the opposite. Our study indicated that vegetation restoration promoted the uniform distribution of SOC and TN on the soil profile. The C/N was relatively stable along vegetation restoration in each soil layer. The accumulation of SOC and TN in the surface soil layer was controlled more by vegetation factors, while that in the lower layer was controlled by both vegetation factors and soil factors.

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