Loss-on-ignition and the carbon contents of Australian soils

Soil Research ◽  
1982 ◽  
Vol 20 (2) ◽  
pp. 147 ◽  
Author(s):  
AV Spain ◽  
ME Probert ◽  
RF Isbell ◽  
RD John
Keyword(s):  
Organic Matter ◽  
High Temperature ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Clay Content ◽  
Loss On Ignition ◽  
Temperature Loss ◽  
Ignition Loss ◽  
Variance Explained

Regression relationships between high temperature loss-on-ignition and organic carbon values are presented for data from a range of Australian soils. Inclusion of the clay content markedly improves the proportion of variance explained by the regressions. It is shown that soils differ in their regressions of organic carbon on loss-on-ignition. Loss-on-ignition is concluded to be a useful index of soil organic matter status closely related to organic carbon levels.

scholarly journals Relationship between the mass of organic matter and carbon in soil

2008 ◽  
Vol 51 (2) ◽  
pp. 263-269 ◽  
Author(s):  
Silmara R. Bianchi ◽  
Mario Miyazawa ◽  
Edson L. de Oliveira ◽  
Marcos Antonio Pavan
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Soil Depth ◽  
Soil Surface ◽  
Soil Samples ◽  
Loss On Ignition ◽  
Oxidation Degree ◽  
Wide Range

The quantity of soil organic matter (SOM) was estimated through the determination of soil organic carbon (SOC) times a factor, which assumes that 58% of the SOM was formed by carbon. A number of soil samples with wide range of SOC content collected in the state of Paraná, Brazil were evaluated in the laboratory. SOC was measured by Walkley-Black method and the total SOM by loss on ignition. The SOC was positively correlated with SOM. The SOM/SOC ratio varied from 1.91 to 5.08 for the soils. It shows that Brazilian SOM has greater oxidation degree. Although, the SOM and SOC decreased with soil depth the SOM/SOC ratio increased. It showed that SOM in the subsoil contained more oxygen but less carbon than the SOM in the upper soil surface. The CEC/SOC also increased with depth indicating that the functional groups of the SOM increased per unity of carbon.

A soil carbon index to gauge soil health in England and Wales

2020 ◽  
Author(s):  
Jonah Prout ◽  
Keith Shepherd ◽  
Steve McGrath ◽  
Guy Kirk ◽  
Stephan Haefele
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Physical Properties ◽  
Soil Structure ◽  
Soil Health ◽  
Clay Content ◽  
Soil Physical Properties ◽  
Arable Soils ◽  
England And Wales

<p>Soil organic carbon (SOC) is a key indicator of soil health, however, guideline values which indicate degradation and good status have been difficult to define. For soils in England and Wales, indicative management ranges were developed using ranges of SOC from the National Soil Inventory of England and Wales (NSI) for precipitation and clay content classes (Verheijen et al., 2005). Soils with higher clay content are often expected to have higher SOC content and this was evident in the management ranges. SOC interacts with clay particles through surface interactions and this, alongside occlusion in aggregates, is suggested to help protect SOC from decomposition and loss (Dungait et al., 2012). The management ranges, however, lacked a mechanistic perspective such that these might not be optimal ranges for soil physical properties and soil structure.</p><p>We have used the NSI to investigate how thresholds of clay/SOC might be used to assess SOC status. A clay/SOC ratio of 10 was proposed as a clay-SOC association capacity derived from correlations with soil physical properties (Dexter et al., 2008) and a further two thresholds (clay/SOC = 8 and 13) were proposed to indicate very good and degraded soil structural quality alongside the original threshold (Johannes et al., 2017). Comparing the distribution of soils under different land uses with the clay/SOC threshold ranges gave an increasing quality trend of arable << ley grassland < permanent grassland ≈ forest. The results suggested that 37% of arable soils would be considered degraded compared with 6% for grassland soils.</p><p>We have used the thresholds to define an index on a scale where negative values indicate degraded soils, and positive values (up to 1) suggest increasing quality beyond which a soil is considered very good. Data from the Woburn ley-arable rotation experiment (Johnston et al., 2017) have also been evaluated with this index to see how the index value might change with time under different managements. As a quantitative metric for SOC, this could form a monitoring framework and feed into other soil health schemes to assess a soil with respect to a clay-interaction capacity and expected soil quality.</p><p> </p><p>References</p><p>Dexter et al. (2008). Complexed organic matter controls soil physical properties. <em>Geoderma</em>, <em>144</em>(3–4), 620–627.</p><p>Dungait et al. (2012). Soil organic matter turnover is governed by accessibility not recalcitrance. <em>Global Change Biology</em>, <em>18</em>, 1781–1796.</p><p>Johannes et al. (2017). Optimal organic carbon values for soil structure quality of arable soils. Does clay content matter? <em>Geoderma</em>, <em>302</em>, 111.</p><p>Johnston et al. (2017). Changes in soil organic matter over 70 years in continuous arable and ley-arable rotations on a sandy loam soil in England. <em>European Journal of Soil Science</em>, <em>68</em>, 305-316.</p><p>Verheijen et el. (2005). Organic carbon ranges in arable soils of England and Wales. <em>Soil Use and Management</em>, <em>21</em>, 2–9.</p>

Soil organic matter formation is controlled by the chemistry and bioavailability of organic carbon inputs across different land uses

2021 ◽  
Vol 770 ◽  
pp. 145307
Author(s):  
Mohammad Bahadori ◽  
Chengrong Chen ◽  
Stephen Lewis ◽  
Sue Boyd ◽  
Mehran Rezaei Rashti ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Land Uses ◽  
Soil Organic Matter Formation

scholarly journals Microbiological properties and oxidizable organic carbon fractions of an oxisol under coffee with split phosphorus applications and irrigation regimes

2013 ◽  
Vol 37 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Adriana Rodolfo da Costa ◽  
Juliana Hiromi Sato ◽  
Maria Lucrécia Gerosa Ramos ◽  
Cícero Célio de Figueiredo ◽  
Géssica Pereira de Souza ◽  
...  
Keyword(s):  
Organic Matter ◽  
Acid Phosphatase ◽  
Soil Organic Matter ◽  
Organic Carbon ◽  
Microbial Biomass Carbon ◽  
Block Design ◽  
Phosphorus Fertilization ◽  
Carbon Fractions ◽  
Irrigation Regimes ◽  
Organic Carbon Fractions

Phosphorus fertilization and irrigation increase coffee production, but little is known about the effect of these practices on soil organic matter and soil microbiota in the Cerrado. The objective of this study was to evaluate the microbiological and oxidizable organic carbon fractions of a dystrophic Red Latossol under coffee and split phosphorus (P) applications and different irrigation regimes. The experiment was arranged in a randomized block design in a 3 x 2 factorial design with three split P applications (P1: 300 kg ha-1 P2O5, recommended for the crop year, of which two thirds were applied in September and the third part in December; P2: 600 kg ha-1 P2O5, applied at planting and then every two years, and P3: 1,800 kg ha-1 P2O5, the requirement for six years, applied at once at planting), two irrigation regimes (rainfed and year-round irrigation), with three replications. The layers 0-5 and 5-10 cm were sampled to determine microbial biomass carbon (MBC), basal respiration (BR), enzyme activity of acid phosphatase, the oxidizable organic carbon fractions (F1, F2, F3, and F4), and total organic carbon (TOC). The irrigation regimes increased the levels of MBC, microbial activity and acid phosphatase, TOC and oxidizable fractions of soil organic matter under coffee. In general, the form of dividing P had little influence on the soil microbial properties and OC. Only P3 under irrigation increased the levels of MBC and acid phosphatase activity.

scholarly journals Relationship between soil oxidizable carbon and physical, chemical and mineralogical properties of umbric ferralsols

2011 ◽  
Vol 35 (1) ◽  
pp. 25-40 ◽  
Author(s):  
Flávio Adriano Marques ◽  
Márcia Regina Calegari ◽  
Pablo Vidal-Torrado ◽  
Peter Buurman
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Clay Content ◽  
Selective Extraction ◽  
Total Carbon ◽  
Soil Matrix ◽  
Soil Variables ◽  
Physical Chemical ◽  
Mineralogical Properties ◽  
Extractable Al

The occurrence of Umbric Ferralsols with thick umbric epipedons (> 100 cm thickness) in humid Tropical and Subtropical areas is a paradox since the processes of organic matter decomposition in these environments are very efficient. Nevertheless, this soil type has been reported in areas in the Southeast and South of Brazil, and at some places in the Northeast. Aspects of the genesis and paleoenvironmental significance of these Ferralsols still need a better understanding. The processes that made the umbric horizons so thick and dark and contributed to the preservation of organic carbon (OC) at considerable depths in these soils are of special interest. In this study, eight Ferralsols with a thick umbric horizon (UF) under different vegetation types were sampled (tropical rain forest, tropical seasonal forest and savanna woodland) and their macromorphological, physical, chemical and mineralogical properties studied to detect soil characteristics that could explain the preservation of high carbon amounts at considerable depths. The studied UF are clayey to very clayey, strongly acidic, dystrophic, and Al-saturated and charcoal fragments are often scattered in the soil matrix. Kaolinites are the main clay minerals in the A and B horizons, followed by abundant gibbsite and hydroxyl-interlayered vermiculite. The latter was only found in UFs derived from basalt rock in the South of the country. Total carbon (TC) ranged from 5 to 101 g kg-1 in the umbric epipedon. Dichromate-oxidizable organic carbon represented nearly 75 % of TC in the thick A horizons, while non-oxidizable C, which includes recalcitrant C (e.g., charcoal), contributed to the remaining 25 % of TC. Carbon contents were not related to most of the inorganic soil variables studied, except for oxalate-extractable Al, which individually explained 69 % (P < 0.001) of the variability of TC in the umbric epipedon. Clay content was not suited as predictor of TC or of the other studied C forms. Bulk density, exchangeable Al3+, Al saturation, ECEC and other parameters obtained by selective extraction were not suitable as predictors of TC and other C forms. Interactions between organic matter and poorly crystalline minerals, as indicated by oxalate-extractable Al, appear to be one of the possible organic matter protection mechanisms of these soils.

Relationships between extractable Al, selected soil properties, pH buffer capacity and lime requirement in some acidic Queensland soils

Soil Research ◽  
1992 ◽  
Vol 30 (2) ◽  
pp. 119 ◽  
Author(s):  
RL Aitken
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Properties ◽  
Buffer Capacity ◽  
Clay Content ◽  
Ph Buffering ◽  
Ph Buffer ◽  
Mineral Soils ◽  
Chloride Salts ◽  
Hydrolysis Of

The objectives of this study were to examine (1) interrelationships between various forms of extractable A1 and selected soil properties, (2) the contribution of extractable A1 to pH buffer capacity, and (3) investigate the use of extractable A1 to predict lime requirement. Aluminium was extracted from each of 60 Queensland soils with a range of chloride salts: 1 M KCl (AlK), 0.5 M CuCl2 (AlCu), 0.33 M LaCl3 (AlLa) and 0.01 M CaCl2 (AlCa). The amounts of A1 extracted were in the order AlCu > AlLa > Alk > AlCa. Little or no A1 was extracted by KC1 or Lac13 in soils with pHw values greater than 5.5 , whereas CuCl2 extracted some A1 irrespective of soil pH. The greater amounts of A1 extracted by CuCl2 were attributed mainly to A1 from organic matter, even though all of the soils were mineral soils (organic carbon 54.7%). Both AlCu and AlLa, were significantly (P < 0.001) correlated with organic carbon, whereas none of the extractable A1 measures was correlated with clay content. AlK and A~L, were poorly correlated to pH buffer capacity. The linear relationship between AlCu and pH buffer capacity (r2 = 0.49) obtained in this study supports the view of previous researchers that the hydrolysis of A1 adsorbed by organic matter is a source of pH buffering in soils. However, the change in CEC with pH accounted for 76% of the variation in pH buffer capacity, indicating that other mechanisms such as deprotonation of organic groups and variable charge minerals are also involved in pH buffering. The ability of CuCl2 and LaCl3extractable Al to estimate lime requirement depended on the target pH. The results suggest that lime requirements based on neutralization of AlLa would be sufficient to raise pHw to around 5.5, whereas requirements based on neutralization of AlCu substantially overestimated the actual lime requirement to pHw 5.5, but gave a reasonable estimation of the lime requirement to pHw 6 5.

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