scholarly journals Preliminary 14C Dates on Bulk Soil Organic Matter from the Black Creek Megafauna Fossil Site, Rocky River, Kangaroo Island, South Australia

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 437-443 ◽  
Author(s):  
Matt Forbes ◽  
Erick Bestland ◽  
Rod Wells
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
South Australia ◽  
Organic Content ◽  
Bulk Soil ◽  
Data Set ◽  
Radiocarbon Age ◽  
Modern Soil ◽  
Minimum Age ◽  
Age Determinations

Radiocarbon age determinations and stratigraphy suggest that the deposits in Black Creek Swamp on Kangaroo Island record 3 phases of deposition and associated soil development which spanned at least the last 20,000 yr. Four new 14C age determinations on bulk soil organic matter and their stratigraphic context are presented in this paper. Three of these age determinations (FP6: 15,687 ± 110 BP [WK11487]; FP7: 16,326 ± 385 BP [WK11488]; and FP8: 17,618 ± 447 BP [WK11489]), are from the organic-rich fossil layer located 45–75 cm below the current floodplain surface. The fourth, a much younger date, FP5: 5589 ± 259 BP (WK11486), was obtained from the base of the overlying modern soil. The dates for the fossil layer increase systematically with depth and correlate well with 5 previous 14C dates (Hope et al., unpublished), ranging between 15,040 ± 120 BP and 19,000 ± 310 BP. This suggests that the data set represents a possible minimum age of the bulk organic matter, and considering the high organic matter contents of approximately 8%, has implications for the age of the megafauna buried in this layer. The overlying modern soil, with its much younger date, contains lower levels of organic matter (3–7%) and gastropods not seen in the fossil layer. This suggests a substantial change in environmental conditions probably due to an alteration in the floodplain drainage conditions. This chronological and sedimentalogical discontinuity indicates that 2 distinct depositional regimes existed and were separated by up to 10,000 14C yr. A calcareous, sandy silt deposit underlying the fossil layer is a calcarenite deposit with low total organic content and is considered the base of the section; it suggests a third separate depositional episode. As such, the Black Creek Swamp in the southwest corner of Kangaroo Island formed intermittently over at least the last 20,000 yr during 3 distinct depositional phases, one of which was the formation of the fossil-laden, organic-rich floodplain surface, which has a possible minimum age of approximately 15,000 to 19,000 BP.

scholarly journals Combination of Numerical Dating Techniques Using 10Be in Rock Boulders and 14C of Resilient Soil Organic Matter for Reconstructing the Chronology of Glacial and Periglacial Processes in a High Alpine Catchment during the Late Pleistocene and Early Holocene

Radiocarbon ◽  
2009 ◽  
Vol 51 (2) ◽  
pp. 537-552 ◽  
Author(s):  
Filippo Favilli ◽  
Markus Egli ◽  
Dagmar Brandova ◽  
Susan Ivy-Ochs ◽  
Peter W Kubik ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Late Quaternary ◽  
Chemical Characterization ◽  
Soil Formation ◽  
Parent Material ◽  
Surface Dynamics ◽  
Exposure Dating ◽  
Minimum Age ◽  
Absolute Dating

Glacier fluctuations and paleoclimatic oscillations during the Late Quaternary in Val di Rabbi (Trentino, northern Italy) were reconstructed using a combination of absolute dating techniques (14C and 10Be) and soil chemical characterization. Extraction and dating of the stable fraction of soil organic matter (SOM) gave valuable information about the minimum age of soil formation and contributed to the deciphering of geomorphic surface dynamics. The comparison of 10Be surface exposure dating (SED) of rock surfaces with the 14C ages of resilient (resistant to H2O2 oxidation) soil organic matter gave a fairly good agreement, but with some questionable aspects. It is concluded that, applied with adequate carefulness, dating of SOM with 14C might be a useful tool in reconstructing landscape history in high Alpine areas with siliceous parent material. The combination of 14C dating of SOM with SED with cosmogenic 10Be (on moraines and erratic boulders) indicated that deglaciation processes in Val di Rabbi were already ongoing by around 14,000 cal BP at an altitude of 2300 m asl and that glacier oscillations might have affected the higher part of the region until about 9000 cal BP. 10Be and 14C ages correlate well with the altitude of the sampling sites and with the established Lateglacial chronology.

Distortion of carbon isotope excursion in bulk soil organic matter during the Paleocene-Eocene thermal maximum

2016 ◽  
Vol 128 (9-10) ◽  
pp. 1352-1366 ◽  
Author(s):  
Allison A. Baczynski ◽  
Francesca A. McInerney ◽  
Scott L. Wing ◽  
Mary J. Kraus ◽  
Paul E. Morse ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Carbon Isotope ◽  
Bulk Soil ◽  
Carbon Isotope Excursion ◽  
Thermal Maximum

Towards a minimum data set to assess soil organic matter quality in agricultural soils

1994 ◽  
Vol 74 (4) ◽  
pp. 367-385 ◽  
Author(s):  
E. G. Gregorich ◽  
M. R. Carter ◽  
D. A. Angers ◽  
C. M. Monreal ◽  
B. H. Ellert
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Quality ◽  
Minimum Data Set ◽  
Data Sets ◽  
Data Set ◽  
Organic Matter Quality ◽  
Carbon And Nitrogen ◽  
Minimum Data ◽  
Soil Organic Matter Quality

Soil quality is a composite measure of both a soil’s ability to function and how well it functions, relative to a specific use. Soil quality can be assessed using a minimum data set comprising soil attributes such as texture, organic matter, pH, bulk density, and rooting depth. Soil organic matter has particular significance for soil quality as it can influence many different soil properties including other attributes of the minimum data set. Assessment of soil organic matter is a valuable step towards identifying the overall quality of a soil and may be so informative as to be included in minimum data sets used to evaluate the world’s soils.In this review, soil organic matter is considered to encompass a set of attributes rather than being a single entity. Included among the attributes and discussed here are total soil organic carbon and nitrogen, light fraction and macroorganic (particulate) matter, mineralizable carbon and nitrogen, microbial biomass, soil carbohydrates and enzymes. These attributes are involved in various soil processes, such as those related to nutrient storage, biological activity, and soil structure, and can be used to establish different minimum data sets for the evaluation of soil organic matter quality. Key words: Biological activity, minimum data set, nutrient storage, soil organic matter, soil quality, soil structure

scholarly journals A Journey from Roots to Bulk Soil: Organic Matter Characterization in the Biosphere 2 Tropical Rainforest

2020 ◽  
Author(s):  
Rachel Cruz Pérez ◽  
Roya AminiTabrizi ◽  
Teverrick Chee ◽  
Hans Gieschen ◽  
Laura Meredith ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Tropical Rainforest ◽  
Bulk Soil ◽  
Biosphere 2

scholarly journals Temperature sensitivity of decomposition in relation to soil organic matter pools: critique and outlook

2005 ◽  
Vol 2 (4) ◽  
pp. 317-321 ◽  
Author(s):  
M. Reichstein ◽  
T. Kätterer ◽  
O. Andrén ◽  
P. Ciais ◽  
E.-D. Schulze ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Temperature Sensitivity ◽  
Model Parameters ◽  
Data Set ◽  
Organic Matter Quality ◽  
Higher Temperature ◽  
Soil Organic Carbon Pools ◽  
Q10 Values ◽  
Soil Organic Matter Quality

Abstract. Knorr et al. (2005) concluded that soil organic carbon pools with longer turnover times are more sensitive to temperature. We show that this conclusion is equivocal, largely dependent on their specific selection of data and does not persist when the data set of Kätterer et al. (1998) is analysed in a more appropriate way. Further, we analyse how statistical properties of the model parameters may interfere with correlative analyses that relate the Q10 of soil respiration with the basal rate, where the latter is taken as a proxy for soil organic matter quality. We demonstrate that negative parameter correlations between Q10-values and base respiration rates are statistically expected and not necessarily provide evidence for a higher temperature sensitivity of low quality soil organic matter. Consequently, we propose it is premature to conclude that stable soil carbon is more sensitive to temperature than labile carbon.

scholarly journals Variation of soil organic matter depends on light-fraction organic matter under long-term monocropping of different crops  

2021 ◽  
Author(s):  
Futao Zhang ◽  
Yunfa Qiao ◽  
Xiaozeng Han ◽  
Bin Zhang
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Principal Component ◽  
Light Fraction ◽  
Bulk Soil ◽  
Density Fractions ◽  
Chemical Structures ◽  
Light Fraction Organic Matter ◽  
The Difference

Cultivating crops influences soil organic matter (SOM), but the effect of different crops remains unclear, particularly under long-term monocropping. The objective of this study was to identify how different crops influence the content and chemical structures of SOM under long-term monocropping. Here, soils were sampled (0–20 cm) under 27-year soybean and maize monocropping and separated into different physical fractions. The content and chemical structures of SOM in all fractions were determined. SOM contents were higher under soybean than maize in bulk soil and macroaggregates and their light-fractions instead of microaggregates and silt and clay. The difference in SOM chemical structure was observed in aggregates and density fractions rather than bulk soils and supported by the result of principal component analysis. The proportion of O-alkyl C in macro- and microaggregates and all free light fractions and that of aromatic C in mineral-associated fractions were higher, while that of carbonyl C was lower under maize than soybean. These results demonstrated that different crops monocropping influences the content and chemical structures of SOM, and the variations were mainly in the light-fraction SOM and highlight a higher sensitivity of physical fractions than bulk soil to different crops.  

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