scholarly journals Soil Organic 14C Dynamics: Effects of Pasture Installation on Arable Land

Radiocarbon ◽  
1997 ◽  
Vol 40 (2) ◽  
pp. 1023-1031 ◽  
Author(s):  
Paul F. A. M. Römkens ◽  
Jan Hassink ◽  
Johannes Van der Plicht
Keyword(s):  
Organic Matter ◽  
Soil Carbon ◽  
Arable Land ◽  
Isotope Ratios ◽  
Vertical Displacement ◽  
Heavy Fraction ◽  
Physical Fractionation ◽  
Fractionation Method ◽  
Heavy Fractions ◽  
Fraction Density

In a study addressing composition and recovery of soil carbon following pasture installation on arable land, radiocarbon isotope ratios were measured in size- and density-separated soil organic matter (SOM) fractions in a pasture and maize plot. The average soil carbon age increased with depth from 444 yr in the 0–30-cm layer to 2456 yr in the 60–80-cm layer in the pasture soils, and from 42 to 1625 yr in the maize-cultivated soil. Weight fractionation of the macro-organic matter (size >150 μm) in a light (density <1.17 g cm-3) intermediate (1.17 g cm-3 < density < 1.37 g cm-3), and heavy fraction (density >1.37 g cm-3) resulted in markedly different ages for different fractions with ages increasing from 2 yr in the light fraction to >3000 yr in the heavy fractions. 13C and 14C (accelerator mass spectrometry (AMS)) isotope ratios in the <20 μm fraction in the 60–80-cm layer indicated that vertical displacement of colloidal organic material occurred during maize cropping. The physical fractionation method, in combination with natural level 13C and 14C analysis, resulted in a better insight in carbon dynamics that occur after the conversion of arable land to pasture.

Leys and soil organic matter:III. The accumulation of macro-organic matter in the soil under different swards

1972 ◽  
Vol 78 (2) ◽  
pp. 333-341 ◽  
Author(s):  
E. A. Garwood ◽  
C. R. Clement ◽  
T. E. Williams
Keyword(s):  
Organic Matter ◽  
Soil Carbon ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Arable Land ◽  
N Fertilizer ◽  
Plant Debris ◽  
Total Soil ◽  
Grazed Swards ◽  
Mesh Sieve

SUMMARYMacro-organic matter (roots and partially decomposed plant debris retained on a 0·25 mm mesh sieve) was measured in soils under various swards. Under a grazed perennial ryegrass/white clover sward, sown on arable land, macro-organic matter in the top 15 cm of soil rose steadily in the first 8 years to 15·8 t/ha, but subsequently declined. Under arable cropping there was great variation with crop and season. Under grass, most of the macro-organic matter accumulated in the top 2 cm of soil, particularly during the first 3 or 4 years. More macro-organic matter was found under perennial ryegrass/white clover than under cocksfoot/white clover swards.After 3 years under grass macro-organic matter accounted for 10% of the total soil carbon, and represented about half the increase in soil carbon.Half, or less, of the nitrogen which accumulated in soil under grass was in the macroorganic matter fraction. The differences between swards which received no N fertilizer and those which received 940 kg/ha over 3 years was small, 16–40 kg N/ha respectively for cut and frequently grazed swards. The ratio of C:N in macro-organic matter under different swards averaged 22:1.

Understanding soil carbon sequestration following the afforestation of former arable land by physical fractionation

CATENA ◽  
2017 ◽  
Vol 150 ◽  
pp. 317-327 ◽  
Author(s):  
Xinhui Han ◽  
Fazhu Zhao ◽  
Xiaogang Tong ◽  
Jian Deng ◽  
Gaihe Yang ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Soil Carbon ◽  
Arable Land ◽  
Soil Carbon Sequestration ◽  
Physical Fractionation

Leys and soil organic matter

1964 ◽  
Vol 63 (3) ◽  
pp. 377-383 ◽  
Author(s):  
C. R. Clement ◽  
T. E. Williams
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Soil Carbon ◽  
Seed Production ◽  
Arable Land ◽  
Row Crops

1. The increase in soil carbon has been assessed in arable land sown to different leys variously managed.2. Under swards cut for herbage conservation, carbon in the top 15 cm. of soil increased by about 0-05 % each year. Although an increase of 0-3 % was found immediately under drills of cocksfoot grown for seed production, there was no increase midway between the drills and, for a given area of land, the carbon increment under such row-crops is probably similar to that under cut swards.

scholarly journals A Comparison of Physical Soil Organic Matter Fractionation Methods for Amended Soils

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Sarah Duddigan ◽  
Liz J. Shaw ◽  
Paul D. Alexander ◽  
Chris D. Collins
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Aggregate Size ◽  
Sample Pretreatment ◽  
Physical Fractionation ◽  
Method Selection ◽  
Irish Moss ◽  
Organic Matter Fractionation ◽  
History Of ◽  
Fractionation Method

Selecting a suitable physical fractionation method, to investigate soil organic matter dynamics, from the plethora that are available is a difficult task. Using five different physical fractionation methods, on soils either nontreated or with a history of amendment with a range of exogenous organic matter inputs (Irish moss peat; composted horse manure; garden compost) and a resulting range of carbon contents (6.8 to 22.2%), we show that method selection had a significant impact on both the total C recovered and the distribution of the recovered C between unprotected, physically protected, or chemically protected conceptual pools. These between-method differences most likely resulted from the following: (i) variation in the methodological fractions obtained (i.e., distinguishing between aggregate size classes); (ii) their subsequent designation to conceptual pools (e.g., protected versus unprotected); and (iii) the procedures used in sample pretreatment and subsequent aggregate dispersion and fractionation steps. The performance of each method also varied depending on the amendment in question. The findings emphasise the need for an understanding of the nature of the soil samples under investigation, and the stabilisation mechanism of interest, both prior to method selection and when comparing and interpreting findings from literature studies using different fractionation methods.

scholarly journals Comparison of Fractionation Methods for Soil Organic Matter 14C Analysis

Radiocarbon ◽  
1996 ◽  
Vol 38 (2) ◽  
pp. 219-229 ◽  
Author(s):  
Susan E. Trumbore ◽  
Shuhui Zheng
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Chemical Separation ◽  
Base Hydrolysis ◽  
Soil Carbon Dynamics ◽  
Physical Fractionation ◽  
Physical Density ◽  
Refractory Organic Matter ◽  
Acid And Base ◽  
Fractionation Method

14C measurements provide a useful test for determining the degree to which chemical and physical fractionation of soil organic matter (SOM) are successful in separating labile and refractory organic matter components. Results from AMS measurements of fractionated SOM made as part of several projects are summarized here, together with suggestions for standardization of fractionation procedures. Although no single fractionation method will unequivocally separate SOM into components cycling on annual, decadal and millennial time scales, a combination of physical (density separation or sieving) and chemical separation methods (combined acid and base hydrolysis) provides useful constraints for models of soil carbon dynamics in several soil types.

scholarly journals Storage of soil carbon as particulate and mineral associated organic matter in irrigated woody perennial crops

Geoderma ◽  
2021 ◽  
Vol 403 ◽  
pp. 115185
Author(s):  
Andrew J. Midwood ◽  
Kirsten D. Hannam ◽  
Tirhas Gebretsadikan ◽  
David Emde ◽  
Melanie D. Jones
Keyword(s):  
Organic Matter ◽  
Soil Carbon ◽  
Perennial Crops ◽  
Woody Perennial
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