Spatial variability of organic and inorganic carbon stocks in Hungry Steppe (Uzbekistan)

2020 ◽  
Author(s):  
Sophia Demina ◽  
Viacheslav Vasenev ◽  
Kristina Ivashchenko ◽  
Inna Brianskaia ◽  
Bakhtiyor Pulatov ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Carbon ◽  
Soil Salinity ◽  
Inorganic Carbon ◽  
Carbon Stocks ◽  
Total Carbon ◽  
Soil Inorganic Carbon ◽  
Organic And Inorganic Carbon ◽  
Soil Carbon Stocks ◽  
Soil Inorganic

<p>Desertification is an important soil treat, affecting soil functions and ecosystem services   in arid and semiarid climate zones. Salinization is one of the principal processes which follows desertification and has a negative impact on soil properties and functions. Carbon sequestration is considered a principle soil function and the decline in soil carbon stocks in one of the main negative consequences of soil degradation. Soil salinization is caused by combination of natural factors (e.g. dry climate condition and high table of mineralized ground waters) and human activities such as improper water management. Globally, soils of the areas affected by salinization are considered to be poor in organic carbon due to low biomass and hampered microbiological activity. However, the contribution of inorganic carbon to the total carbon stocks in these areas can be comparable. Considering that soil inorganic carbon is more stable to mineralization compared to organic carbon, soil carbon stocks in saline landscape shall not be neglected.</p><p>Central Asian regions and especially the Aral Sea basin have been historically affected by desertification enhancing soil salinity. Hungry Steppe (Mirzachul) is an area of historical desertification and salinization, covering around 10000 km<sup>2</sup> at the territories of Uzbekistan, South Kazakhstan and Tajikistan. The region has a sharp continental climate with large seasonal fluctuations. Dry and semidesertic steppe vegetation dominates the natural areas (mainly coincided with high soil salinity), whereas most of the areas is managed to produce cotton, perennial grasses, melons and gourds. Soils are dominated by serozems corresponding to Calcisols in WRB soil classification. The research aimed to analyze the effect of salinization on carbon stocks in Hungry Steppe. To achieve this aim, soil carbon stocks were estimated at the four collective farms, referred as Water Consumer Assiociations (WCAs) or ‘shirkats’ in Syrdarya province: Khavast district in Yangier WCA, Mirzaobod district in Beruniy WCA  Oq Oltin district in Andijan WCA and Syrdarya district in Sobir  Rakhimov WCA. The selected sites belonged to different in land quality classes, based on the land evaluation survey carried out by the melioration expedition of the Ministry of Agriculture and Water Resources of Uzbekistan in 201,  from the lowest (Mirzaobod) to the highest (S. Rahimov). Soil pH, electroconductivity, chlorides, organic and inorganic carbon stocks and total nitrogen stocks were estimated for each of the areas. Although the internal variability in the analyzed parameters was high we clearly showed the highest stocks of soil inorganic carbon in the most salinized area, whereas the highest stocks of organic carbon were shown for the most fertile lands. However, we didn’t ding significant difference in the total carbon stocks between the sites. It can be concluded that desertification has more effect on the redistribution of organic and inorganic forms of carbon, rather than on the total carbon stocks.</p><p><strong>Acknowledgements </strong>The experimental research was performed with the support of the Russian Foundation for Basic Research, Project # 18-54-41004 and Ministry of Innovation development of the Republic of Uzbekistan, Project # MRU-SQV 86/2017. Data analysis and mapping was supported by the RUDN project “5-100”.</p>

scholarly journals The southern Brazilian grassland biome: soil carbon stocks, fluxes of greenhouse gases and some options for mitigation

2012 ◽  
Vol 72 (3 suppl) ◽  
pp. 673-681 ◽  
Author(s):  
VD Pillar ◽  
CG Tornquist ◽  
C Bayer
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Greenhouse Gases ◽  
Soil Carbon ◽  
Carbon Stocks ◽  
Soil Tillage ◽  
Nitrous Oxide Emissions ◽  
Greenhouse Gases Emissions ◽  
Soil Carbon Stocks ◽  
Grassland Biome

The southern Brazilian grassland biome contains highly diverse natural ecosystems that have been used for centuries for grazing livestock and that also provide other important environmental services. Here we outline the main factors controlling ecosystem processes, review and discuss the available data on soil carbon stocks and greenhouse gases emissions from soils, and suggest opportunities for mitigation of climatic change. The research on carbon and greenhouse gases emissions in these ecosystems is recent and the results are still fragmented. The available data indicate that the southern Brazilian natural grassland ecosystems under adequate management contain important stocks of organic carbon in the soil, and therefore their conservation is relevant for the mitigation of climate change. Furthermore, these ecosystems show a great and rapid loss of soil organic carbon when converted to crops based on conventional tillage practices. However, in the already converted areas there is potential to mitigate greenhouse gas emissions by using cropping systems based on no soil tillage and cover-crops, and the effect is mainly related to the potential of these crop systems to accumulate soil organic carbon in the soil at rates that surpass the increased soil nitrous oxide emissions. Further modelling with these results associated with geographic information systems could generate regional estimates of carbon balance.

scholarly journals Agro-forestry Systems as a Means to Achieve Carbon Co-benefits in Nepal

2016 ◽  
Vol 13 (1) ◽  
pp. 59-68
Author(s):  
Roshan M. Bajracharya ◽  
Him Lal Shrestha ◽  
Ramesh Shakya ◽  
Bishal K. Sitaula
Keyword(s):  
Organic Carbon ◽  
Soil Properties ◽  
Soil Carbon ◽  
Bulk Density ◽  
Agricultural Land ◽  
Carbon Stocks ◽  
Community Forests ◽  
C Stocks ◽  
Soil Carbon Stocks ◽  
Agro Forestry

Land management regimes and forest types play an important role in the productivity and accumulation of terrestrial carbon pools. While it is commonly accepted that forests enhance carbon sequestration and conventional agriculture causes carbon depletion, the effects of agro-forestry are not well documented. This study investigated the carbon stocks in biomass and soil, along with the selected soil properties in agro-forestry plots compared to community forests (CF) and upland farms in Chitwan, Gorkha and Rasuwa districts of Central Nepal during the year 2012-2013. We determined the total above ground biomass carbon, soil organic carbon (SOC) stocks and soil properties (bulk density, organic carbon per cent, pH, total nitrogen (TN), available phosphorus (P), exchangeable potassium (K), and cation exchange capacity (CEC)) on samples taken from four replicates of 500 m2 plots each in community forests, agro-forestry systems and agricultural land. The soil was sampled in two increments at 0-15 cm and 15-30 cm depths and intact cores removed for bulk density and SOC determination, while loose samples were separately collected for the laboratory analysis of other soil properties. The mean SOC percent and corresponding soil carbon stocks to 30 cm depth were generally highest in CF (3.71 and 3.69 per cent, and 74.98 and 76.24 t ha-1, respectively), followed by leasehold forest (LHF) (2.26 and 1.13 per cent and 40.72 and 21.34 t ha-1, respectively) and least in the agricultural land (3.05 and 1.09 per cent, and 63.54 and 19.42 t ha-1, respectively). This trend was not, however, observed in Chitwan, where agriculture (AG) had the highest SOC content (1.98 per cent) and soil carbon stocks (42.5 t ha-1), followed by CF (1.8 per cent and 41.2 t ha-1) and leasehold forests (1.56 per cent and 35.3 t ha-1) although the differences were not statistically significant. Other soil properties were not significantly different among land use types with the exceptions of pH, total N, available P and CEC in the Chitwan plots. Typically, SOC and soil carbon stocks (to 30cm depth) were positively correlated with each other and with TN and CEC. The AGB-C was expectantly highest in Rasuwa district CF (ranging from 107.3 to 260.3 t ha-1) due to dense growth and cool climate, followed by Gorkha (3.1 to 118.4 t ha-1), and least in Chitwan (17.6 to 95.2 t ha-1). The highest C stocks for agro-forestry systems in both above ground and soil were observed in Rasuwa, followed by Chitwan district. Besides forests, agro-forestry systems also hold good potential to store and accumulate carbon, hence they have scope for contributing to climate change mitigation and adaptation with co-benefits.Journal of Forest and Livelihood 13(1) May, 2015, page: 56-68

Organic carbon partitioning in soil and litter in subtropical woodlands and open forests: a case study from the Brigalow Belt, Queensland

2006 ◽  
Vol 28 (2) ◽  
pp. 115 ◽  
Author(s):  
S. H. Roxburgh ◽  
B. G. Mackey ◽  
C. Dean ◽  
L. Randall ◽  
A. Lee ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Carbon ◽  
Bulk Density ◽  
Soil Surface ◽  
Soil Bulk Density ◽  
Carbon Stocks ◽  
Soil Carbon Stocks ◽  
Landscape Scales ◽  
Open Forests

A woodland–open forest landscape within the Brigalow Belt South bioregion of Queensland, Australia, was surveyed for soil organic carbon, soil bulk density and soil-surface fine-litter carbon. Soil carbon stocks to 30 cm depth across 14 sites, spanning a range of soil and vegetation complexes, ranged from 10.7 to 61.8 t C/ha, with an overall mean of 36.2 t C/ha. Soil carbon stocks to 100 cm depth ranged from 19.4 to 150.5 t C/ha, with an overall mean of 72.9 t C/ha. The standing stock of fine litter ranged from 1.0 to 7.0 t C/ha, with a mean of 2.6 t C/ha, and soil bulk density averaged 1.4 g/cm3 at the soil surface, and 1.6 g/cm3 at 1 m depth. These results contribute to the currently sparse database of soil organic carbon and bulk density measurements in uncultivated soils within Australian open forests and woodlands. The estimates of total soil organic carbon stock calculated to 30 cm depth were further partitioned into resistant plant material (RPM), humus (HUM), and inert organic matter (IOM) pools using diffuse mid-infrared (MIR) analysis. Prediction of the HUM and RPM pools using the RothC soil carbon model agreed well with the MIR measurements, confirming the suitability of RothC for modelling soil organic carbon in these soils. Methods for quantifying soil organic carbon at landscape scales were also explored, and a new regression-based technique for estimating soil carbon stocks from simple field-measured soil attributes has been proposed. The results of this study are discussed with particular reference to the difficulties encountered in the collection of the data, their limitations, and opportunities for the further development of methods for quantifying soil organic carbon at landscape scales.

Relationship between soil inorganic carbon and organic carbon in the wheat-maize cropland of the North China Plain

2017 ◽  
Vol 418 (1-2) ◽  
pp. 423-436 ◽  
Author(s):  
H. J. Shi ◽  
X. J. Wang ◽  
Y. J. Zhao ◽  
M. G. Xu ◽  
D. W. Li ◽  
...  
Keyword(s):  
Organic Carbon ◽  
North China Plain ◽  
North China ◽  
Inorganic Carbon ◽  
Soil Inorganic Carbon ◽  
The North ◽  
The North China Plain ◽  
Soil Inorganic

Carbon storage in cotton soils of northern New South Wales

Soil Research ◽  
2003 ◽  
Vol 41 (5) ◽  
pp. 889 ◽  
Author(s):  
T. A. Knowles ◽  
B. Singh
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Soil Carbon ◽  
Inorganic Carbon ◽  
Carbon Pool ◽  
Total Carbon ◽  
Soil Types ◽  
Soil Carbon Pool ◽  
Total Soil

Soil carbon is an important component of the global carbon cycle with an estimated pool of soil organic carbon of about 1500 Gt. There are few estimates of the pool of inorganic carbon, but it is thought to be approximately 50% of the organic carbon pool. There is no detailed study on the estimation of the soil carbon pool for Australian soils.In order to quantify the carbon pools and to determine the extent of spatial variability in the organic and inorganic carbon pools, 120 soil cores were taken down to a depth of 0.90 m from a typical cotton field in northern NSW. Three cores were also taken from nearby virgin bushland and these samples were used as paired samples. Each soil core was separated into 4 samples, i.e. 0–0.15, 0.15–0.30, 0.30–0.60, and 0.60–0.90 m. Soil organic carbon was determined by wet oxidation and inorganic carbon content was determined using the difference between total carbon and organic carbon, and confirmed by the acid dissolution method. Total carbon was measured using a LECO CHN analyser. Soil organic carbon of the field constituted 62% (0–0.15 m), 58% (0.15–0.30 m), 60% (0.30–0.60 m), and 67% (0.60–0.90 m) of the total soil carbon. The proportion of inorganic carbon in total carbon is higher than the global average of 32%. Organic carbon content was relatively higher in the deeper layers (>0.30�m) of the studied soils (Vertosols) compared with other soil types of Australia. The carbon content varied across the field, however, there was little correlation between the soil types (grey, red, or intergrade colour) and carbon content. The total soil carbon pool of the studied field was estimated to be about 78 t/ha for 0–0.90 m layer, which was approximately 58% of the total soil carbon in the soil under nearby remnant bushland (136 t/ha). The total pool of carbon in the cotton soils of NSW was estimated to be 44.8 Mt C, where organic carbon and inorganic carbon constitute 34.9 Mt C and 9.9 Mt C, respectively. Based on the results of a limited number of paired sites under remnant vegetation, it was estimated that about 18.9 Mt of C has been lost from Vertosols by cotton cropping in NSW. With more sustainable management practices such as conservation tillage and green manuring, some of the lost carbon can be resequestered, which will help to mitigate the greenhouse effect, improve soil quality and may increase crop yield.

scholarly journals CUT CYCLES AND SOIL CARBON POTENTIAL STOCKS IN A MANAGED FOREST IN THE CAATINGA DOMAIN IN BRAZIL

2020 ◽  
Vol 33 (3) ◽  
pp. 735-745
Author(s):  
JOSÉ FRÉDSON BEZERRA LOPES ◽  
EUNICE MAIA DE ANDRADE ◽  
ERICH CELESTINO BRAGA PEREIRA ◽  
DIEGO ANTUNES CAMPOS ◽  
DEODATO DO NASCIMENTO AQUINO
Keyword(s):  
Organic Carbon ◽  
Soil Carbon ◽  
Carbon Potential ◽  
Carbon Stocks ◽  
Tropical Dry Forests ◽  
Charcoal Production ◽  
Managed Forest ◽  
Dry Forests ◽  
Soil Carbon Stocks

ABSTRACT Management of tropical dry forests in Brazil expanded 450% in the two latest decades; but little is known about the dynamics of these areas. Thus, the objective of this work was to evaluate if the recovery of mean original biomass stocks (MOBS) is a consistent criterion to define cut cycles in a managed forest for charcoal production, and determine the remaining biomass and its contribution to soil carbon stocks. The study was conducted at the Ramalhete Settlement, in General Sampaio, CE, Brazil, in 2018. The explorable shrubby-arboreous biomass (ESAB) and the ESAB mean annual increases (ESAB -MAI) were determined in five areas subjected to clearcutting after 3, 5, 8, 11, and 15 years, and in a preservation area with 40 years of regeneration. Each area was divided into seven plots (20 × 20 m), totaling 42 plots. The ESAB of the plots were compared and the remaining biomass (branches, stumps, and litterfall) in a recently explored area was calculated and converted into organic carbon. The remaining biomass of branches had higher contribution to soil carbon stocks, followed by the litterfall, and stumps. The carbon stocks of the branch component were 3.4-fold higher than those of the litterfall. The recovery of the MOBS of an area after clearcutting should not be used as a criterion to define the cut cycle, since these original carbon stocks do not represent the maximum ESAB production possible in the area; the biodiversity and amount of ESAB in the classes of larger diameter are more adequate criteria.

Pedogenic knowledge-aided modelling of soil inorganic carbon stocks in an alpine environment

2017 ◽  
Vol 599-600 ◽  
pp. 1445-1453 ◽  
Author(s):  
Ren-Min Yang ◽  
Fan Yang ◽  
Fei Yang ◽  
Lai-Ming Huang ◽  
Feng Liu ◽  
...  
Keyword(s):  
Inorganic Carbon ◽  
Carbon Stocks ◽  
Alpine Environment ◽  
Soil Inorganic Carbon ◽  
Soil Inorganic

Global climate change and soil carbon stocks; predictions from two contrasting models for the turnover of organic carbon in soil

2005 ◽  
Vol 11 (1) ◽  
pp. 154-166 ◽  
Author(s):  
Chris Jones ◽  
Claire McConnell ◽  
Kevin Coleman ◽  
Peter Cox ◽  
Peter Falloon ◽  
...  
Keyword(s):  
Climate Change ◽  
Organic Carbon ◽  
Soil Carbon ◽  
Global Climate Change ◽  
Global Climate ◽  
Carbon Stocks ◽  
Soil Carbon Stocks

Predicting contents of carbon and its component fractions in Australian soils from diffuse reflectance mid-infrared spectra

Soil Research ◽  
2013 ◽  
Vol 51 (8) ◽  
pp. 577 ◽  
Author(s):  
J. A. Baldock ◽  
B. Hawke ◽  
J. Sanderman ◽  
L. M. Macdonald
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Carbon ◽  
Total Nitrogen ◽  
Diffuse Reflectance ◽  
Inorganic Carbon ◽  
Soil Samples ◽  
Mid Infrared ◽  
Organic And Inorganic Carbon ◽  
Mir Spectra

Quantifying the content and composition of soil carbon in the laboratory is time-consuming, requires specialised equipment and is therefore expensive. Rapid, simple and low-cost accurate methods of analysis are required to support current interests in carbon accounting. This study was completed to develop national and state-based models capable of predicting soil carbon content and composition by coupling diffuse reflectance mid-infrared (MIR) spectra with partial least-squares regression (PLSR) analyses. Total, organic and inorganic carbon contents were determined and MIR spectra acquired for 20 495 soil samples collected from 4526 locations from soil depths to 1 m within Australia’s agricultural regions. However, all subsequent MIR/PLSR models were developed using soils only collected from the 0–10, 10–20 and 20–30 cm depth layers. The extent of grinding applied to air-dried soil samples was found to be an important determinant of the variability in acquired MIR spectra. After standardisation of the grinding time, national MIR/PLSR models were developed using an independent test-set validation approach to predict the square-root transformed contents of total, organic and inorganic carbon and total nitrogen. Laboratory fractionation of soil organic carbon into particulate, humus and resistant forms was completed on 312 soil samples. Reliable national MIR/PLSR models were developed using cross-validation to predict the contents of these soil organic carbon fractions; however, further work is required to enhance the representation of soils with significant contents of inorganic carbon. Regional MIR/PLSR models developed for total, organic and inorganic carbon and total nitrogen contents were found to produce more reliable and accurate predictions than the national models. The MIR/PLSR approach offers a more rapid and more cost effective method, relative to traditional laboratory methods, to derive estimates of the content and composition of soil carbon and total nitrogen content provided that the soils are well represented by the calibration samples used to build the predictive models.

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