scholarly journals Physical fractionation of organic carbon in areas under different land uses in the Cerrado

Author(s):  
Adilson A. Costa ◽  
Bruno de O. Dias ◽  
Vânia da S. Fraga ◽  
Charles C. Santana ◽  
Thalita F. Sampaio ◽  
...  

ABSTRACT With the expansion of agricultural production, native Cerrado areas are replaced with other forms of land use. Thus, the objective of this study was to evaluate changes in the physical fractionation of organic carbon (C) in areas under different forms of land use in the Cerrado. The treatments, with five repetitions, corresponded to the following forms of use: area under conventional tillage, area under pasture plantation, area under eucalyptus plantation and area under native Cerrado vegetation, at the depths of 0-5, 5-10, 10-15 and 15-20 cm in the municipality of Luis Eduardo Magalhães, BA, Brazil. The highest C contents and stocks were found in the eucalyptus area, which were equal to those of the area under native Cerrado vegetation, while particulate C stocks were higher in the area under pasture at the depth up to 10 cm, not differing from the area under native Cerrado. Pasture and eucalyptus had positive effect on C management index, regardless of depth.

2017 ◽  
Vol 38 (1) ◽  
pp. 109 ◽  
Author(s):  
Rodrigo Fonseca da Silva ◽  
Glenio Guimarães Santos ◽  
Júlio César Azevedo Nóbrega ◽  
Geraldo César de Oliveira ◽  
Bruno De Oliveira Dias ◽  
...  

The Cerrado biome has outstanding territorial relevance in the state of Piauí, in which weather conditions, relief and favorable soil has made this region one reference in food production. This study focused to evaluate the effects of different land uses, management systems and their respective terms on organic carbon content and physical properties of a Latossolo Amarelo (Oxisol) in the Southwestern Piauí state. The study was performed in the city of Uruçuí, situated in the southwestern Piauí state. We assessed nine farming areas with different backgrounds regarding land-use, management system and run time. The treatments consisted of areas under no-till for 3 and 6 years (NT3 and NT6), under pasture for 2 and 5 years (PA2 and PA6), under eucalyptus plantation for six and twelve years (EU6 and EU12), under conventional tillage for two and 8 years (CT2 and CT8) and under native Cerrado (NC), which represented a reference condition. Conversion of the native Cerrado into no-till and grazing areas increased soil organic carbon content over time.


Author(s):  
Adilson A. Costa ◽  
Bruno de O. Dias ◽  
Vânia da S. Fraga ◽  
Charles C. Santana ◽  
Núbia da Silva

ABSTRACT The soil is an important component in the biogeochemical cycling of carbon (C) and nitrogen (N). The objective of this study was to evaluate the changes caused by different types of land use on the C and N stocks in areas of Cerrado at different depths: area under conventional tillage, no-tillage, grazing, eucalyptus and area under native vegetation of Cerrado in the municipality of Luis Eduardo Magalhães, BA, Brazil. The highest C content was found for no-tillage area in the surface layer up to 10 cm; however, there was a decrease in its content along the depths. Areas under no-tillage had lower values of C in the surface layer (0-5 cm) and below 20 cm. Among these, C stocks were significantly lower compared to the use of grass and eucalyptus at the depth of up to 40 cm. Considering the depth of 0-60 cm, the highest C stock was found in areas under native vegetation, 62.81 Mg ha-1, followed by the area under cultivation with eucalyptus, 60.70 Mg ha-1. The lowest C stocks were found in areas under conventional use, 44.87 Mg ha-1. Conventional planting reduced N stocks by up to 61 and 56% when compared to areas under native Cerrado vegetation and eucalyptus plantations, respectively, both at a depth of up to 10 cm. Therefore, land use practices such as eucalyptus cultivation and no-tillage contribute to C and N storage over time.


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 ◽  
Author(s):  
Dedy Antony ◽  
Jo Clark ◽  
Chris Collins ◽  
Tom Sizmur

<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>


2020 ◽  
Vol 27 (1) ◽  
Author(s):  
Alvyra Šlepetienė ◽  
Kazimiež Duchovski ◽  
Jonas Volungevičius

The aim of this study – to evaluate the status of organic carbon (OC) under different land uses of soils formed in alluvial deposits. The soil samples were collected from 0–10, 10–20 and 20–30 cm depths in three field replicates.Three land uses were investigated: arable land, grassland and forest. The experimental site is situated near Surviliškis, Kėdainiai District (55°26′08.37′′N, 24°02′27.75′′Y) in Central Lowland of Lithuania. A total of 27 soil samples, collected from 0–10, 10–20 and 20–30 cm depths in three field replicates, were analysed for OC. The samples were prepared for analysis by removing plant residues, grinding and sieving through a 0.25 mm sieve. For all land uses, the highest content of OC was found in the upper 0–10 cm soil layer of the soil, with the highest values found in the forest land use. Fast-growing deciduous trees are an effective means to increase the content of OC in alluvial soil, especially in the 0–10 cm layer. The distribution of OC in the soil layers depended on the land use. Grassland and forest land uses allow OC to be preserved throughout the 0–30 cm layer, with less OC differentiation than in arable land. This could be attributed to the specificities of organic matter accumulation and degradation in different land uses. Not only the amount of labile organic carbon (similar to total organic carbon) was highest (0.392 g kg–1) in forest soil in the 0–10 cm layer, it also had a higher relative share in the total organic carbon (2.9%) than in other land uses – arable land and grassland (2.3–2.4%).


2020 ◽  
Vol 12 (4) ◽  
pp. 478-483
Author(s):  
Surya Prabha A.C. ◽  
Velumani R. ◽  
Senthivelu M. ◽  
Arulmani K. ◽  
Pragadeesh S.

Soil organic carbon (SOC) plays a vital role in soil fertility and is important for its contributions to mitigation and adaptation to climate change. The present study was undertaken to estimate the SOC stock in soils under different land uses of Cauvery Delta zone of Tamil Nadu. Four different land uses were selected for the study viz, Forests, Agriculture, Agro-forestry and Plantations. Soil samples were collected from Madukkur and Kalathur soil series of Cauvery Delta zone for soil carbon analysis. The soil samples were fractionated into three aggregate size classes viz., macro-aggregates (250-2000µm), micro-aggregates (53-250 µm) and silt and clay sized fraction (<53 µm). At 0-30 cm depth, the forest land use stored the maximum SOC stock in the different size fractions viz. macro-sized fraction (73.0 Mg ha-1), a micro-sized fraction (76.0 Mg ha-1) and silt+clay sized fraction (77.0 Mg ha-1) in Madukkur series. Agriculture land use registered the lowest SOC stock. Among the different size fractions, silt+clay sized fraction (< 53 µm) retained the maximum SOC in all the land uses. In Kalathur series also, maximum soil organic carbon stock was recorded in forest land use. The data generated in the study will be beneficial to the user groups viz., farmers in identifying the most suitable land use for enhancing the storage of soil organic carbon thereby improving yields of crops and trees.


Author(s):  
Zhenming Zhang ◽  
Xianfei Huang ◽  
Yunchao Zhou ◽  
Jiachun Zhang ◽  
Xubo Zhang

The assessment of soil organic carbon (SOC) in mountainous karst areas is very challenging, due to the high spatial heterogeneity in SOC content and soil type. To study and assess the SOC storage in mountainous karst areas, a total of 22,786 soil samples were collected from 2,854 soil profiles in Guizhou Province in Southwest China. The SOC content in the soil samples was determined by the oxidation of potassium dichromate (K2Cr2O7), followed by titration with iron (II) sulfate (FeSO4). The SOC storage was assessed based on different land uses. The results suggested that the average SOC density in the top 1.00 m of soil associated with different land uses decreased in the following order: Croplands (9.58 kg m−2) > garden lands (9.07 kg m−2) > grasslands (8.07 kg m−2) > forestlands (7.35 kg m−2) > uncultivated lands (6.94 kg m−2). The SOC storage values in the 0.00–0.10 m, 0.00–0.20 m, 0.00–0.30 m and 0.00–1.00 m soil layers of Guizhou Province were 0.50, 0.87, 1.11 and 1.58 Pg, respectively. The SOC in the top 0.30 m of soil accounted for 70.25% of the total within the 0.00–1.00 m layer in Guizhou Province. It was concluded that assessing SOC storage in mountainous karst areas was more accurate when using land use rather than soil type. This result can supply a scientific reference for the accurate assessment of the SOC storage in the karst areas of southwestern China, the islands of Java, northern and central Vietnam, Indonesia, Kampot Province in Cambodia and in the general area of what used to be Yugoslavia, along with other karst areas with similar ecological backgrounds.


2002 ◽  
Vol 32 (3) ◽  
pp. 401-406 ◽  
Author(s):  
Cimélio Bayer ◽  
Deborah Pinheiro Dick ◽  
Genicelli Mafra Ribeiro ◽  
Klaus Konrad Scheuermann

Land use and soil management may affect both labile and humified soil organic matter (SOM) fractions, but the magnitude of these changes is poorly known in subtropical environments. This study investigated effects of four land use and soil management systems (forest, native pasture, and conventional tillage and no-tillage in a wheat/soybean succession) on (i) total soil organic carbon (SOC) stocks (0 to 250mm depth) and on (ii) carbon (C) stocks in labile (coarse, light) and humified (mineral-associated, humic substances) SOM fractions (0 to 25mm depth), in a Hapludox soil from southern Brazil. In comparison to the adjacent forest site, conventionally tilled soil presented 36% (46.2Mg ha-1) less SOC in the 0 to 250mm depth and a widespread decrease in C stocks in all SOM fractions in the 0 to 25mm depth. The coarse (>53 mum) and light (<1kg dm-3) SOM fractions were the most affected under no-tillage, showing 393% (1.22Mg C ha-1) and 289% (0.55Mg C ha-1) increases, respectively, in relation to conventional tillage. Similar results were observed for mineral-associated SOM and humic substance C pools (34% and 38% increases, respectively) under no-tillage. Compared with labile SOM fraction results, the percentual increments on C stocks in humified fractions were smaller; but in absolute terms this C pool yielded the highest increases (3.06 and 2.95Mg C ha-1, respectively). These results showed that both labile and humified organic matter are better protected under the no-tillage system, and consequently less vulnerable to mineralization. Humified SOM stabilization process involving interactions with variable charge minerals is probably important in maintaining and restoring soil and environmental quality in tropical and subtropical regions.


2014 ◽  
Vol 11 (22) ◽  
pp. 6483-6493 ◽  
Author(s):  
C. Ferré ◽  
R. Comolli ◽  
A. Leip ◽  
G. Seufert

Abstract. Effects of forest conversion to poplar plantation on soil organic carbon (SOC) stocks were investigated by sampling paired plots in an alluvial area of the Ticino River in Northern Italy. According to land registers and historical aerial photographs, the two sites were part of a larger area of a 200 yr old natural forest that was partly converted to poplar plantation in 1973. The soil sampling of three layers down to a depth of 100 cm was performed at 90 and 70 points in the natural forest (NF) and in the nearby poplar plantation (PP) respectively. The substitution of the natural forest with the poplar plantation strongly modified soil C stock down to a depth of 55 cm, although the management practices at PP were not intensive. After calculation of equivalent soil masses and of SOC stocks in individual texture classes, the comparison of C stocks showed an overall decrease in SOC of 5.7 kg m−2 or 40% in consequence of 37 years of poplar cultivation. Our case study provides further evidence that (i) spatial heterogeneity of SOC is an important feature in paired plot studies requiring a careful sampling strategy and high enough number of samples; (ii) land use changes through tillage are creating a more homogeneous spatial structure of soil properties and may require the application of dedicated spatial statistics to tackle eventual problems of pseudo-replicates and auto-correlation; (iii) short rotation forests are not properly represented in current reporting schemes for changes of SOC after land use change and may better be considered as cropland.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Sabina Yeasmin ◽  
Eshara Jahan ◽  
Md. Ashik Molla ◽  
A. K. M. Mominul Islam ◽  
Md. Parvez Anwar ◽  
...  

This study aimed to determine the impact of land use on organic carbon (OC) pools of soils with contrasting native organic matter (OM) content. Surface (0–15 cm) soils of four land uses (cropland, orchard, grassland, and fallow) were collected from four agroecological zones (AEZs) of Bangladesh with different OM content (AEZ-7: very low, −3: low, −9: medium, and −5: high). Bulk soils were physically fractionated into particulate and mineral associated OM (POM and MOM: >53 and <53 µm, respectively). Both bulk and fractionated soils were analyzed for OC and nitrogen (N). Among the land uses, undisturbed soils (grassland and fallow land) had significantly higher total OC (0.44–1.79%) than disturbed soils (orchard and cropland) (0.39–1.67%) in all AEZs. The distribution of OC and N in POM and MOM fractions was significantly different among land uses and also varied with native OM content. In all AEZs, cropland soils showed the lowest POM-C content (0.40–1.41%), whereas the orchard soils showed the highest values (0.71–1.91%). The MOM-C was highest (0.81–1.91%) in fallow land and lowest (0.53–1.51%) in orchard, and cropland had a moderate amount (0.70–1.61%). In croplands, distribution of a considerable amount of OC in the MOM pool was noticeable. These findings reveal that total OC in soils can be decreased with cultivation but does not inevitably indicate the loss of OC storage in the stable pool. Carbon storage potential of soils with both high- and low-native OM contents can be increased via proper land use and managements.


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