Using Two Sieves to Characterize Dry Soil Aggregate Size Distribution

1987 ◽  
Vol 30 (1) ◽  
pp. 0162-0165 ◽  
Author(s):  
L. J. Hagen ◽  
E. L. Skidmore ◽  
D. W. Fryrear
Keyword(s):  
Size Distribution ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Aggregate Size Distribution ◽  
Dry Soil

A model for characterizing dry soil aggregate size distribution

CATENA ◽  
2021 ◽  
Vol 198 ◽  
pp. 105018
Author(s):  
Zhongling Guo ◽  
Chunping Chang ◽  
Xueyong Zou ◽  
Rende Wang ◽  
Jifeng Li ◽  
...  
Keyword(s):  
Size Distribution ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Aggregate Size Distribution ◽  
Dry Soil

Aggregate size distribution and stability of an oxisol under legume-based and pure grass pastures in the eastern Colombian savannas

Soil Research ◽  
1995 ◽  
Vol 33 (1) ◽  
pp. 153 ◽  
Author(s):  
AJ Gijsman ◽  
RJ Thomas
Keyword(s):  
Size Distribution ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Hot Water ◽  
Aggregate Size Distribution ◽  
Carbohydrate Concentration ◽  
Stability Measurement ◽  
Water Extractable

This study evaluated soil aggregate size distribution and stability of an Oxisol under improved grass-only or grass-legume pastures, established in previously native savanna. Three grass-legume combinations were included at various stocking rates. In all treatments and soil layers, soils were well aggregated, having more than 90% of their weight in macroaggregates (>250 �m). The addition of legumes to pastures did not affect the soil aggregate size distribution, although aggregates showed somewhat more stability against slaking. An increase in stocking rate negatively affected both average aggregate size and aggregate stability. Aggregates showed little or no dispersion of clay particles in any treatment. A positive correlation was found between wet aggregate stability and hot-water extractable carbohydrate concentration, supporting the hypothesis that these carbohydrates equate with plant-derived or microbial polysaccharides which glue soil aggregates together. It is suggested that determination of hot-water extractable carbohydrates may serve as a useful indicator of small differences in aggregate stability, even when these differences are not evident in the stability measurement itself.

scholarly journals Lithology and climate controlled soil aggregate size distribution and organic carbon stability in the Peruvian Andes

2019 ◽  
Author(s):  
Songyu Yang ◽  
Boris Jansen ◽  
Samira Absalah ◽  
Rutger L. van Hall ◽  
Karsten Kalbitz ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Size Distribution ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Soil Aggregation ◽  
Soil Mineralogy ◽  
Aggregate Size Distribution ◽  
Soc Stocks ◽  
Soc Mineralization

Abstract. Recent studies indicate that climate change influences soil mineralogy by altering weathering processes, and thus impacts soil aggregation and organic carbon (SOC) stability. Alpine ecosystems of the Neotropical Andes are characterized by high SOC stocks, which are important to sustain ecosystem services. However, climate change in the form of altered precipitation patterns can potentially affect soil aggregation and SOC stability with potentially significant effects on the soil’s ecosystem services. This study aimed to investigate the effects of precipitation and lithology on soil aggregation and SOC stability in the Peruvian Andean grasslands, and assessed whether occlusion of organic matter (OM) in aggregates controls SOC stability. For this, samples were collected from limestone soils (LSs) and acid igneous rock soils (ASs) from two sites with contrasting precipitation levels. We used a dry-sieving method to quantify aggregate size distribution, and applied a 76-day soil incubation with intact and crushed aggregates to investigate SOC stability in dependence on aggregation. SOC stocks ranged from 153±27 to 405 ± 42 Mg ha−1, and the highest stocks were found in the LSs of the wet site. We found lithology rather than precipitation to be the key factor regulating soil aggregate size distribution, as indicated by coarse aggregates in the LSs and fine aggregates in the ASs. SOC stability estimated by specific SOC mineralization rates decreased with precipitation in the LSs, but minor differences were found between wet and dry sites in the ASs. Aggregate destruction had a limited effect on SOC mineralization, which indicates that occlusion of OM in aggregates played a minor role in OM stabilization. This was further supported by inconsistent patterns of aggregate size distribution compared to the patterns of SOC stability. We propose that OM adsorption on mineral surfaces is the major OM stabilization mechanism controlling SOC stocks and stability. The results highlight the interactions between precipitation and lithology on SOC stability, which are likely controlled by soil mineralogy in relation to OM input.

Effects of moisture condition and freeze/thaw cycles on surface soil aggregate size distribution and stability

2012 ◽  
Vol 92 (3) ◽  
pp. 529-536 ◽  
Author(s):  
Enheng Wang ◽  
Richard M. Cruse ◽  
Xiangwei Chen ◽  
Aaron Daigh
Keyword(s):  
Water Content ◽  
Size Distribution ◽  
Surface Soil ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Moisture Condition ◽  
Freeze Thaw ◽  
Aggregate Size Distribution ◽  
Disturbed Soil

Wang, E., Cruse, R. M., Chen, X. and Daigh, A. 2012. Effects of moisture condition and freeze/thaw cycles on surface soil aggregate size distribution and stability. Can. J. Soil Sci. 92: 529–536. Freeze/thaw cycles can affect soil aggregate stability, which in turn impacts wind and water erosion. The objectives of this laboratory study were: (1) to determine the effect of variable freeze/thaw cycles and soil water conditions on aggregate size distribution and stability; and (2) to evaluate differences in aggregate size distribution and stability between disturbed soil and undisturbed soil cores as affected by freeze/thaw cycles and soil water conditions. Surface soil was collected before freezing in late fall of 2009. Aggregates isolated from disturbed soil or intact soil cores were subjected to a factorial combination of 3 gravimetric water content treatments: 0.15 m3 m−3, 0.23 m3 m−3 or 0.30 m3 m−3, and 3 freeze/thaw treatments: 0, 3, or 9 cycles. A freeze/thaw cycle involved soil freezing at –10∘C for 24 h, followed by thawing at 5∘C for 24 h. Most aggregate size classes were affected significantly (P<0.05) by freeze/thaw cycles except for wet-sieved aggregates >5 mm. Dry-sieved aggregates were relatively more sensitive to the freeze/thaw treatment than wet-sieved aggregates. The mean weight diameter (MWD) of dry-sieved aggregates was significantly (P<0.05) greater at 0.30 m3 m−3 than 0.15 m3 m−3 water content, but the opposite trend was observed for MWD of wet aggregates and aggregate stability. There was a significant (P<0.05) response of the MWD in dry-sieved aggregates to the interactive freeze/thaw×water content effect that differed for aggregates obtained from disturbed soil and those in the undisturbed soil core, but not for the MWD of wet-sieved aggregates and aggregate stability.

scholarly journals Estimating soil aggregate size distribution from images using pattern spectra

2020 ◽  
Vol 198 ◽  
pp. 63-77
Author(s):  
Petra Bosilj ◽  
Iain Gould ◽  
Tom Duckett ◽  
Grzegorz Cielniak
Keyword(s):  
Size Distribution ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Aggregate Size Distribution

scholarly journals Lithology- and climate-controlled soil aggregate-size distribution and organic carbon stability in the Peruvian Andes

SOIL ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Songyu Yang ◽  
Boris Jansen ◽  
Samira Absalah ◽  
Rutger L. van Hall ◽  
Karsten Kalbitz ◽  
...  
Keyword(s):  
Climate Change ◽  
Ecosystem Services ◽  
Size Distribution ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Soil Aggregation ◽  
Soil Mineralogy ◽  
Aggregate Size Distribution ◽  
Soc Stocks ◽  
Soc Mineralization

Abstract. Recent studies indicate that climate change influences soil mineralogy by altering weathering processes and thus impacts soil aggregation and organic carbon (SOC) stability. Alpine ecosystems of the Neotropical Andes are characterized by high SOC stocks, which are important for sustaining ecosystem services. However, climate change in the form of altered precipitation patterns can potentially affect soil aggregation and SOC stability with potentially significant effects on the soil's ecosystem services. This study aimed to investigate the effects of precipitation and lithology on soil aggregation and SOC stability in the Peruvian Andean grasslands, and it assessed whether occlusion of organic matter (OM) in aggregates controls SOC stability. For this, samples were collected from soils on limestone and soils on acid igneous rocks from two sites with contrasting precipitation levels. We used a dry-sieving method to quantify aggregate-size distribution and applied a 76 d soil incubation with intact and crushed aggregates to investigate SOC stability's dependence on aggregation. SOC stocks ranged from 153±27 to 405±42 Mg ha−1, and the highest stocks were found in the limestone soils of the wet site. We found lithology rather than precipitation to be the key factor regulating soil aggregate-size distribution, as indicated by coarse aggregates in the limestone soils and fine aggregates in the acid igneous rock soils. SOC stability estimated by specific SOC mineralization rates decreased with precipitation in the limestone soils, but only minor differences were found between wet and dry sites in the acid igneous rock soils. Aggregate destruction had a limited effect on SOC mineralization, which indicates that occlusion of OM in aggregates played a minor role in OM stabilization. This was further supported by the inconsistent patterns of aggregate-size distribution compared to the patterns of SOC stability. We propose that OM adsorption on mineral surfaces is the main OM stabilization mechanism controlling SOC stocks and stability. The results highlight the interactions between precipitation and lithology on SOC stability, which are likely controlled by soil mineralogy in relation to OM input.

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