Soil organic carbon, permanganate fractions, and the chemical properties of acidic soils

Soil Research ◽  
1997 ◽  
Vol 35 (6) ◽  
pp. 1301 ◽  
Author(s):  
P. W. Moody ◽  
S. A. Yo ◽  
R. L. Aitken

Total organic carbon (TC) in 32 acidic surface (0–10 cm) soils was divided into 3 fractions (C1, C2, and C3) based on oxidisability by different strengths of KMnO4 (33 mM and 167 mM). With the methodology used, ease of oxidation decreased in the order C1>C2>C3. Several fundamental soil chemical properties were also determined, i.e. ECEC, CEC at pH 6·5 (CEC6·5), slope of the charge curve (ΔCEC), pH buffer capacity, (pHBC), P sorption capacity using a single addition index (PSI150), and content of organically complexed Al. All soils had pH (1:5 water) <6·5, and comprised a wide range of soil types and clay contents. Multiple step-up regression indicated that C fractions were significantly (P < 0·05) correlated with ECEC, ΔCEC, CEC6·5, and pHBC. These results reinforce the critical importance of soil organic matter to the fundamental soil chemical properties of predominantly variable charge soils. The intercorrelations between the various oxidisable C fractions made it difficult to elucidate if degree of oxidisability had any bearing on the reactivity of the organic matter. ECEC was primarily correlated with C1, whereas all C fractions had highly significant (P < 0·01) effects on ΔCEC and pHBC. The fraction which was most difficult to oxidise, C3, made a significant (P < 0·01) contribution to CEC6·5 when combined with clay and ECEC in a multiple regression equation. Generally, one or other of the C fractions was better correlated with the fundamental soil chemical properties than TC. This simple empirical fractionation of soil organic C may therefore be a useful tool for assessing the effects of soil management on these properties.

2021 ◽  
Vol 8 (2) ◽  
pp. 80-89
Author(s):  
Saroj Koirala ◽  
Santosh Shrestha ◽  
Prashanta Raut ◽  
Bikram Pandey ◽  
Arbindra Timilsina

Soil chemical properties plays a crucial role in crop yield. In this study, we evaluated the chemical properties of soils under three different cropping systems practiced for more than five years in Changunarayan municipality of Bhaktapur district of Nepal. The cropping systems includes- (i) cultivation inside polyhouse (Treatment A: polyhouse), (ii) paddy-wheat rotation (Treatment B: P-W), and (iii) paddy-wheat-vegetable rotation (Treatment C: P-W-V). Thirty-nine composite samples (13 replicates from each site) were taken from the area based on variation in landforms. Soil pH, organic matter (%), total nitrogen (%), available phosphorus (mgkg-1), and available potassium (mgkg-1) were evaluated for each sample. The study revealed that the soil pH was acidic and ranges between 4.71 and 5.39, organic matter (1.6-2.39%), total nitrogen (0.091-0.13%), phosphorus (4.48-29.24mg kg-1) and potassium (88.04-109.52 mg kg-1). A significant lower mean pH (4.71), and higher mean organic matter (2.39%), total nitrogen (0.13%) and available phosphorus (29.24 mgkg-1) were observed in cultivation under polyhouse. Incorporation of vegetable in paddy-wheat system gave significant (p<0.05) higher accumulation of soil phosphorus and consistently raised other nutrient status. Moreover, cultivation under polyhouse raised C:N ratio (10.55) significantly than other system. This finding can be relevant to wide range of readers that focus on soil chemical properties and can be used in developing future research strategy and sustainable soil management system in the area.


Author(s):  
Samuel Tetsopgang

Local tropical soils were amended with pulverized rock fines such as trachyte, basalt, pyroclastic materials, limestone and gneiss with ± manure in different proportions in Cameroon. And soil textures and chemicals were assessed after harvesting. Cabbage and potatoes as test crops treated with fines of pyroclastic materials and basalts, portrayed highest and lowest productivities, respectively. The early loamy sand texture of controls changes to clay; and clay textures remained unchanged after treatments. This indicates the decrease of sand proportion and gain in clay particles after treatments. The pH of local soils was strongly to slightly acidic (4.8 ≤ pH ≤ 6.5) and rose up to slightly acidic and slightly alkaline affinity (6.6 ≤ pH ≤ 7.2). A significant pH increase from 5.9 to 6.9 was observed on a treated sample with pulverized pyroclastic materials. Organic carbon and Organic matter show parallel oscillated tendencies from controls to treated soils. There is a general increase of Mg and Ca after treatments while Na and K remain constant. Rock fines from trachyte, limestone and basalt as treatments significantly increase phosphorus in soils with contents of 96.0, 51.5 and 50.9 ppm, respectively.


Soil Research ◽  
1998 ◽  
Vol 36 (5) ◽  
pp. 809 ◽  
Author(s):  
M. J. Bell ◽  
P. W. Moody ◽  
R. D. Connolly ◽  
B. J. Bridge

The relationships between fractions of soil organic carbon (C) oxidised by varying strengths of potassium permanganate (KMnO4) and important soil physical and chemical properties were investigated for Queensland Ferrosols. These soils spanned a wide range of clay contents (31-83%), pH values (4·4-7·9; 1 : 5 water), and total C contents (12· 1-111 g/kg). Carbon fractions were derived by oxidation with 33 mM (C1), 167 mM (C2), and 333 mM (C3) KMnO4, while organic C and total C were determined by Heanes wet oxidation and combustion, respectively. Aggregate stability was determined by wet sieving soil from the surface crust after 30 min of high intensity (100 mm/h), simulated rainfall on disturbed samples in the laboratory. The proportion of aggregates <0·125 mm (P125) was used as the stability indicator because of the high correlation between this size class and the final rainfall infiltration rate (r2 = 0qa86, n = 42). The soil organic C fraction most closely correlated with P125 was C1 (r2 = 0·79, n = 42). This fraction was also highly correlated with final, steady-state infiltration rates in field situations where there were no subsurface constraints to infiltration (r2 = 0·74, n = 30). Multiple linear regression techniques were used to identify the soil properties determining effective cation exchange capacity (ECEC, n = 89). Most variation in ECEC (R2 = 0 ·72) was accounted for by a combination of C1 (P < 0·0001) and pH (P < 0·0001). These results confirm the very important role played by the most labile (easily oxidised) fraction of soil organic matter (C1) in key components of the chemical and physical fertility of Ferrosols. Management practices which maintain adequate C1 concentrations are essential for sustainable cropping on these soils.


2020 ◽  
Vol 3 (1) ◽  
pp. 33-50
Author(s):  
Onwuchekwa Ojimgba

The influence of grasscover in restoring the eroded soils was carried out in Umudike, Southestern Nigeria. The use of grass has attracted considerable research attention with respect to forage production and erosion control. Little information is available on the influence of this grasscover management on soil physical and chemical properties. Four different grasses namely: Paspalum notatum(PN), Panicum maximum(PM), Axonopus compressus(AC) and Vetiver grass(VG)- Vetiveria zizanioid/es) were used in this study and their influence on eroded soil tested in two locations. This study has shown that the soils planted with the grasses gave significantly (p<0.05) higher results of the physical and some chemical properties than their adjacent open bare soil. In all the parameters considered in this study, the values obtained in soils under Paspalum notatum was higher than those obtained in PM, AC, VG and their adjacent bare soils(BS). The soils under PN had generally lower bulk density, higher total porosity and hydraulic conductivity than other grasses and adjacent open bare soil in both locations. The soil under PN proved best, outperforming PM, VG,and AC in stabilizing soil aggregates. Planting of PN on eroded soil significantly (p<0.05) increased the mean weight diameter from 0.77mm (BSPN1) to 1.31mm (PN1) and 0.82mm (BSPN2) to 1.48mm (PN2) for Locations 1 and 2, respectively. The relative improvement in Location 1 was in the order : PN1>AC1=VG1>PM1>BSVG1=BSPN1>BSAC1=BSPM1. Also, soils under PN had significantly higher values of pH, organic C and organic matter, total nitrogen and available P more than other grasses and their adjacent open soils. The magnitude of increase in Location 1 was in the order : PN1>AC1>PM1=VG1>BSVG1=BSPN1=BSAC1>BSPM1. Location 2 also increased in the same trend. The organic carbon content of PN increased from 0.73%(BSPN1) to 2.89%(PN1) and 0.88%(BSPN2) to 2.91%(PN2) in Locations 1 and 2, respectively. Also, the organic matter content of the soil increased in the same trend as organic carbon content.


The influence of grasscover in restoring the eroded soils was carried out in Umudike, Southestern Nigeria. The use of grass has attracted considerable research attention with respect to forage production and erosion control. Little information is available on the influence of this grasscover management on soil physical and chemical properties. Four different grasses namely: Paspalum notatum(PN), Panicum maximum(PM), Axonopus compressus(AC) and Vetiver grass(VG)- Vetiveria zizanioid/es) were used in this study and their influence on eroded soil tested in two locations. This study has shown that the soils planted with the grasses gave significantly (p<0.05) higher results of the physical and some chemical properties than their adjacent open bare soil. In all the parameters considered in this study, the values obtained in soils under Paspalum notatum was higher than those obtained in PM, AC, VG and their adjacent bare soils(BS). The soils under PN had generally lower bulk density, higher total porosity and hydraulic conductivity than other grasses and adjacent open bare soil in both locations. The soil under PN proved best, outperforming PM, VG,and AC in stabilizing soil aggregates. Planting of PN on eroded soil significantly (p<0.05) increased the mean weight diameter from 0.77mm (BSPN1) to 1.31mm (PN1) and 0.82mm (BSPN2) to 1.48mm (PN2) for Locations 1 and 2, respectively. The relative improvement in Location 1 was in the order : PN1>AC1=VG1>PM1>BSVG1=BSPN1>BSAC1=BSPM1. Also, soils under PN had significantly higher values of pH, organic C and organic matter, total nitrogen and available P more than other grasses and their adjacent open soils. The magnitude of increase in Location 1 was in the order :PN1>AC1>PM1=VG1>BSVG1=BSPN1=BSAC1>BSPM1. Location 2 also increased in the same trend. The organic carbon content of PN increased from 0.73%(BSPN1) to 2.89%(PN1) and 0.88%(BSPN2) to 2.91%(PN2) in Locations 1 and 2, respectively. Also, the organic matter content of the soil increased in the same trend as organic carbon content.


Author(s):  
Hylda Permata Riantara ◽  
Marga Mandala

Cassava has an important role as a potential caloric source for the community. Cassava has been known as a plant with wide range adaptability, thus it is very potential to be cultivated in areas with highly variated agro-ecological conditions such as temperate regions, marginal land, and dryland. This research aimed to study the chemical properties of suboptimal dryland in Panji, Kendit and Kapongan Subdistrict, Situbondo Regency for the development of cassava cultivation. The research was carried out by doing surveys and taking soil samples of suboptimal dryland in Subdistricts of Panji, Kendit, and Kapongan. Each subdistrict had 5 locations chosen as site obtaining soil samples. The soil samples were taken at a depth of 20 cm, each soil sample was put into a plastic clip, then was labeled and brought to the Soil Fertility Laboratory for analysis of soil chemical properties. The soil chemical properties analyzed were pH H2O, cation exchange capacity (CEC), organic carbon, total Nitrogen, available Phosphate, and available Kalium. The results showed that the organic carbon, total Nitrogen, and available Phosphate became a limiting factor which belonged to the category of very low to low, with organic carbon of 0.80-1.44%, total Nitrogen of 0.12-0.17% and available Phosphate of 15.21-15.97 ppm. Nevertheless, the soil chemical properties of suboptimal dryland are quite suitable for cassava, however other inputs are needed to the soil by fertilizing the organic matter, Nitrogen, and Phosphate.


Soil Research ◽  
1986 ◽  
Vol 24 (2) ◽  
pp. 293 ◽  
Author(s):  
RC Dalal ◽  
RJ Mayer

Distribution of soil organic carbon in sand-, silt- and clay-size fractions during cultivation for periods ranging from 20 to 70 years was studied in six major soils used for cereal cropping in southern Queensland. Particle-size fractions were obtained by dispersion in water using cation exchange resin, sieving and sedimentation. In the soils' virgin state no single particle-size fraction was found to be consistently enriched as compared to the whole soil in organic C in all six soils, although the largest proportion (48%) of organic C was in the clay-size fraction; silt and sand-size fractions contained remaining organic C in equal amounts. Upon cultivation, the amounts of organic C declined from all particle-size fractions in most soils, although the loss rates differed considerably among different fractions and from the whole soil. The proportion of the sand-size fraction declined rapidly (from 26% to 12% overall), whereas that of the clay-size fraction increased from 48% to 61% overall. The proportion of silt-size organic C was least affected by cultivation in most soils. It was inferred, therefore, that the sand-size organic matter is rapidly lost from soil, through mineralization as well as disintegration into silt-size and clay-size fractions, and that the clay fraction provides protection for the soil organic matter against microbial and enzymic degradation.


2016 ◽  
Author(s):  
Zhaolian Ye ◽  
Jiashu Liu ◽  
Aijun Gu ◽  
Feifei Feng ◽  
Yuhai Liu ◽  
...  

Abstract. Knowledge on aerosol chemistry in densely populated regions is critical for reduction of air pollution, while such studies haven't been conducted in Changzhou, an important manufacturing base and polluted city in the Yangtze River Delta (YRD), China. This work, for the first time, performed a thorough chemical characterization on the fine particular matter (PM2.5) samples, collected during July 2015 to April 2016 across four seasons in Changzhou city. A suite of analytical techniques were employed to characterize organic carbon / elemental carbon (OC / EC), water-soluble organic carbon (WSOC), water-soluble inorganic ions (WSIIs), trace elements, and polycyclic aromatic hydrocarbons (PAHs) in PM2.5; in particular, an Aerodyne soot particle aerosol mass spectrometer (SP-AMS) was deployed to probe the chemical properties of water-soluble organic aerosols (WSOA). The average PM2.5 concentrations were found to be 108.3 μg m−3, and all identified species were able to reconstruct ~ 80 % of the PM2.5 mass. The WSIIs occupied about half of the PM2.5 mass (~ 52.1 %), with SO42−, NO3− and NH4+ as the major ions. On average, nitrate concentrations dominated over sulfate (mass ratio of 1.21), indicating influences from traffic emissions. OC and EC correlated well with each other and the highest OC / EC ratio (5.16) occurred in winter, suggesting complex OC sources likely including both secondarily formed and primarily emitted OA. Concentrations of eight trace elements (Mn, Zn, Al, B, Cr, Cu, Fe, Pb) can contribute up to 6.0 % of PM2.5 during winter. PAHs concentrations were also high in winter (140.25 ng m−3), which were predominated by median/high molecular weight PAHs with 5- and 6-rings. The organic matter including both water-soluble and water-insoluble species occupied ~ 20 % PM2.5 mass. SP-AMS determined that the WSOA had an average atomic oxygen-to-carbon (O / C), hydrogen-to-carbon (H / C), nitrogen-to-carbon (N / C) and organic matter-to-organic carbon (OM / OC) ratios of 0.36, 1.54, 0.11, and 1.74, respectively. Source apportionment of WSOA further identified two secondary OA (SOA) factors (a less oxidized and a more oxidized OA) and two primary OA (POA) factors (a nitrogen enriched hydrocarbon-like traffic OA and a cooking-related OA). On average, the POA contribution overweighed SOA (55 % vs. 45 %), indicating the important role of local anthropogenic emissions to the aerosol pollution in Changzhou. Our measurement also shows the abundance of organic nitrogen species in WSOA, and the source analyses suggest these species likely associated with traffic emissions, which warrants more investigations on PM samples from other locations.


Soil Research ◽  
2018 ◽  
Vol 56 (6) ◽  
pp. 632 ◽  
Author(s):  
Kathryn Conrad ◽  
Ram C. Dalal ◽  
Ryosuke Fujinuma ◽  
Neal W. Menzies

Stabilisation and protection of soil organic carbon (SOC) in macroaggregates and microaggregates represents an important mechanism for the sequestration of SOC. Legume-based grass pastures have the potential to contribute to aggregate formation and stabilisation, thereby leading to SOC sequestration. However, there is limited research on the C and N dynamics of soil organic matter (SOM) fractions in deep-rooted legume leucaena (Leucaena leucocephala)–grass pastures. We assessed the potential of leucaena to sequester carbon (C) and nitrogen (N) in soil aggregates by estimating the origin, quantity and distribution in the soil profile. We utilised a chronosequence (0–40 years) of seasonally grazed leucaena stands (3–6 m rows), which were sampled to a depth of 0.3 m at 0.1-m intervals. The soil was wet-sieved for different aggregate sizes (large macroaggregates, >2000 µm; small macroaggregates, 250–2000 µm; microaggregates, 53–250 µm; and <53 µm), including occluded particulate organic matter (oPOM) within macroaggregates (>250 µm), and then analysed for organic C, N and δ13C and δ15N. Leucaena promoted aggregation, which increased with the age of the leucaena stands, and in particular the formation of large macroaggregates compared with grass in the upper 0.2 m. Macroaggregates contained a greater SOC stock than microaggregates, principally as a function of the soil mass distribution. The oPOM-C and -N concentrations were highest in macroaggregates at all depths. The acid nonhydrolysable C and N distribution (recalcitrant SOM) provided no clear distinction in stabilisation of SOM between pastures. Leucaena- and possibly other legume-based grass pastures have potential to sequester SOC through stabilisation and protection of oPOM within macroaggregates in soil.


Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7451
Author(s):  
Barbara Breza-Boruta ◽  
Karol Kotwica ◽  
Justyna Bauza-Kaszewska

Properly selected tillage methods and management of the available organic matter resources are considered important measures to enable farming in accordance with the principles of sustainable agriculture. Depending on the depth and intensity of cultivation, tillage practices affect soil chemical composition, structure and biological activity. The three-year experiment was performed on the soil under spring wheat (cv. Tybalt) short-time cultivation. The influence of different tillage systems and stubble management on the soil’s chemical and biological parameters was analyzed. Organic carbon content (OC); content of biologically available phosphorus (Pa), potassium (Ka), and magnesium (Mg); content of total nitrogen (TN), mineral nitrogen forms: N-NO3 and N-NH4 were determined in various soil samples. Moreover, the total number of microorganisms (TNM), bacteria (B), actinobacteria (A), fungi (F); soil respiratory activity (SR); and pH in 1 M KCl (pH) were also investigated. The results show that organic matter amendment is of greater influence on soil characteristics than the tillage system applied. Manure application, as well as leaving the straw in the field, resulted in higher amounts of organic carbon and biologically available potassium. A significant increase in the number of soil microorganisms was also observed in soil samples from the experimental plots including this procedure.


Sign in / Sign up

Export Citation Format

Share Document