Effects of heating on some soil physical properties related to its hydrological behaviour in two north-western Spanish soils

2004 ◽  
Vol 13 (2) ◽  
pp. 195 ◽  
Author(s):  
R. García-Corona ◽  
E. Benito ◽  
E. de Blas ◽  
M. E. Varela
Keyword(s):  
Organic Matter ◽  
Hydraulic Conductivity ◽  
Physical Properties ◽  
Size Distribution ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Total Porosity ◽  
Water Repellency ◽  
Aggregate Size Distribution ◽  
Distribution Water

Two forest soils rich in organic matter but differing in texture (sandy loam and silty loam) were heated under controlled laboratory conditions in order to examine the consequences of the heating effect that accompanies the passage of a fire on the physical properties of soil. Three samples of both soils were heated for 30 min in a muffle furnace at temperatures of 25, 170, 220, 380 and 460°C. At each temperature, the following parameters were determined: dry aggregate size distribution, water aggregate stability, total porosity, pore size distribution, water repellency and hydraulic conductivity. Heating the soils at 170 and 220°C caused no significant changes in aggregate size distribution or total porosity but increased water aggregate stability and the volume of pores 0.2–30 μm. Also, increased water repellency and strongly decreased the hydraulic conductivity. All parameters underwent much more dramatic changes at 380 and 460°C that can be ascribed to the combustion of organic matter. At such temperatures, water repellency was destroyed and the low hydraulic conductivity can be attributed to the aggregate breakdown observed under dry and wet conditions.

scholarly journals Study of soil aggregate breakdown dynamics under low dispersive ultrasonic energies with sedimentation and X-ray attenuation

2015 ◽  
Vol 29 (4) ◽  
pp. 501-508 ◽  
Author(s):  
Jasmin Schomakers ◽  
Franz Zehetner ◽  
Axel Mentler ◽  
Franz Ottner ◽  
Herwig Mayer
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Size Distribution ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
X Ray ◽  
Aggregate Size Distribution ◽  
Aggregate Breakdown ◽  
Wet Sieving

Abstract It has been increasingly recognized that soil organic matter stabilization is strongly controlled by physical binding within soil aggregates. It is therefore essential to measure soil aggregate stability reliably over a wide range of disruptive energies and different aggregate sizes. To this end, we tested highaccuracy ultrasonic dispersion in combination with subsequent sedimentation and X-ray attenuation. Three arable topsoils (notillage) from Central Europe were subjected to ultrasound at four different specific energy levels: 0.5, 6.7, 100 and 500 J cm-3, and the resulting suspensions were analyzed for aggregate size distribution by wet sieving (2 000-63 μm) and sedimentation/X-ray attenuation (63-2 μm). The combination of wet sieving and sedimentation technique allowed for a continuous analysis, at high resolution, of soil aggregate breakdown dynamics after defined energy inputs. Our results show that aggregate size distribution strongly varied with sonication energy input and soil type. The strongest effects were observed in the range of low specific energies (< 10 J cm-3), which previous studies have largely neglected. This shows that low ultrasonic energies are required to capture the full range of aggregate stability and release of soil organic matter upon aggregate breakdown.

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.

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.

Tillage-induced changes to soil structure and organic carbon fractions in New Zealand soils

Soil Research ◽  
2001 ◽  
Vol 39 (3) ◽  
pp. 465 ◽  
Author(s):  
T. G. Shepherd ◽  
S. Saggar ◽  
R. H. Newman ◽  
C. W. Ross ◽  
J. L. Dando
Keyword(s):  
Organic Carbon ◽  
Size Distribution ◽  
Soil Structure ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Aggregate Size Distribution ◽  
Binding Agents ◽  
Rate Of Decline ◽  
Humic Soil

The effects of increasing cropping and soil compaction on aggregate stability and dry-sieved aggregate-size distribution, and their relationship to total organic C (TOC) and the major functional groups of soil organic carbon, were investigated on 5 soils of contrasting mineralogy. All soils except the allophanic soil showed a significant decline in aggregate stability under medium- to long-term cropping. Mica-rich, fine-textured mineral and humic soils showed the greatest increase in the mean weight diameter (MWD) of dry aggregates, while the oxide-rich soils, and particularly the allophanic soils, showed only a slight increase in the MWD after long-term cropping. On conversion back to pasture, the aggregate stability of the mica-rich soils increased and the MWD of the aggregate-size distribution decreased, with the humic soil showing the greatest recovery. Aggregate stability and dry aggregate-size distribution patterns show that soil resistance to structural degradation and soil resilience increased from fine-textured to coarse-textured to humic mica-rich soils to oxide-rich soils to allophanic soils. Coarse- and fine-textured mica-rich and oxide-rich soils under pasture contained medium amounts of TOC, hot-water soluble carbohydrate (WSC), and acid hydrolysable carbohydrate (AHC), all of which declined significantly under cropping. The rate of decline varied with soil type in the initial years of cropping, but was similar under medium- and long-term cropping. TOC was high in the humic mica-rich and allophanic soils, and levels did not decline appreciably under medium- and long-term cropping. 13C-nuclear magnetic resonance evidence also indicates that all major functional groups of soil organic carbon declined under cropping, with O-alkyl C and alkyl C showing the fastest and slowest rate of decline, respectively. On conversion back to pasture, both WSC and AHC returned to levels originally present under long-term pasture. TOC recovered to original pasture levels in the humic soil, but recovered only to 60–70% of original levels in the coarse- and fine-textured soils. Aggregate stability was strongly correlated to TOC, WSC, and AHC (P < 0.001), while aggregate-size distribution was moderately correlated to aggregate stability (P < 0.01) and weakly correlated to AHC (P < 0.05). Scanning electron microscopy indicated a loss of the binding agents around aggregates under cropping. The effect of the loss of these binding agents on soil structure was more pronounced in mica-rich soils than in oxide-rich and allophanic soils. The very high aggregate stabilities of the humic soil under pasture was attributed to the presence of a protective water-repellent lattice of long-chain polymethylene compounds around the soil aggregates.

Correlation between stability, structural indicators and organic matter in soils used for growing malting barley

2013 ◽  
Vol 61 (3) ◽  
pp. 237-246 ◽  
Author(s):  
J. Prieto Méndez ◽  
O. Acevedo Sandoval ◽  
F. Prieto García
Keyword(s):  
Organic Matter ◽  
Size Distribution ◽  
Structural Stability ◽  
Close Association ◽  
Negative Relationship ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Simple Random Sampling ◽  
Structure Stability ◽  
Malting Barley

Soil structure stability depends on several factors and its assessment is conducted using different methods and prediction indices. One of the indicators is soil organic matter (SOM), since this helps to keep mineral particles together against destabilizing forces such as wetting and raindrop impact. However, previous studies have emphasized the relationship between aggregate stability and SOM content without considering its type or quality. Therefore, in this study the association between the quality and content of SOM and the structural stability of the surface layer was evaluated in three soils used for growing malting barley in the southern part of Hidalgo State, Mexico. With simple random sampling nine observation points were selected in each soil, where samples were taken in order to determine the stable aggregate size distribution, particle size distribution, content and fractionation of SOM, and the prediction indices of surface sealing and crusting derived from these characteristics. The soils showed low structural stability (except in Apan), as shown by the percentage runoff recorded in the field. There was a close association between the size (from 4 to 2 mm and <0.25 mm) of water-stable aggregates and the different fractions of SOM, while the fulvic acid (FA) fraction had a negative relationship with smaller aggregates (R = −0.84). Finally, it was found that only the FAO crusting index was able to predict the structural stability level in the soil.

Rapid changes in microbial biomass and aggregate size distribution in response to changes in organic matter management in grass pasture

Geoderma ◽  
2013 ◽  
Vol 193-194 ◽  
pp. 68-75 ◽  
Author(s):  
Tunsisa T. Hurisso ◽  
Jessica G. Davis ◽  
Joe E. Brummer ◽  
Mary E. Stromberger ◽  
Maysoon M. Mikha ◽  
...  
Keyword(s):  
Organic Matter ◽  
Microbial Biomass ◽  
Size Distribution ◽  
Aggregate Size ◽  
Aggregate Size Distribution ◽  
Organic Matter Management ◽  
Rapid Changes

scholarly journals The stability of soil aggregates in tilled fallow areas in Hyderabad district, Pakistan

2015 ◽  
Vol 27 (1) ◽  
pp. 51-60
Author(s):  
Ahmed Tagar ◽  
Jan Adamowski
Keyword(s):  
Soil Erosion ◽  
Size Distribution ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Indus River ◽  
Aggregate Size Distribution ◽  
Sieve Size ◽  
The Stability ◽  
The Village

Abstract Arid areas are particularly susceptible to soil erosion due to long dry periods and sudden heavy downpours. This study investigates the aggregate size distribution and aggregate stability of twelve tilled fallow areas of Hyderabad district, Sindh, Pakistan. This study determined aggregate size distribution by dry sieving to evaluate the seedbed condition and aggregate stability using wet sieving to assess the susceptibility of tilled fallow areas to soil erosion. The aggregate size distribution of the soils of the selected areas was highly variable. Gulistan-e-Sarmast had the largest number of clods (51.0%) followed by Kohsar (49.0%), Latifabad # 10 (41.10%) and Daman-e-Kohsar (39.0%). Fazal Sun City, the left side of the Indus River, the Village Nooral Detha and the left side of the Abdullah Sports city had a greater number of large (>8.0 mm) and small aggregates (<0.5 mm). The optimum aggregate size distribution was found in the left side of the channel, which had the largest number of aggregates (50.50%) in the 0.5–8.0 mm sieve size range. Maximum aggregate stability (AS) was found in Gulistan-e-Sarmast (46%), Kohsar (42%) and Latifabad # 10 (34%), while all other soils had minimum aggregate stability (<14%). The minimum aggregate stabilities demonstrate that the tilled fallow areas of Hyderabad district are highly susceptible to erosion. Therefore, the present study suggests investigating potential ways to enhance the aggregate stabilities of soils.

scholarly journals Soil aggregate size distribution and total organic carbon in intra-aggregate fractions as affected by addition of biochar and organic amendments

2020 ◽  
Vol 53 (1) ◽  
pp. 41
Author(s):  
George O. Odugbenro ◽  
Zhihua Liu ◽  
Yankun Sun
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Size Distribution ◽  
Microbial Biomass Carbon ◽  
Soil Depth ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Font Size ◽  
Aggregate Size Distribution

<p>A two-year field trial on maize (<em>Zea mays</em> L.) production was established to determine the influence of biochar, maize straw, and poultry manure on soil aggregate stability, aggregate size distribution, total organic carbon (TOC), and soil microbial biomass carbon (MBC). Seven treatments with four replications, namely CK, control; S, 12.5 Mg ha-1 straw; B1, 12.5 Mg ha-1 biochar; B2, 25 Mg ha-1 biochar; SB1, straw + 12.5 Mg ha-1 biochar; SB2, straw + 25 Mg ha-1 biochar; and M, 25 Mg ha-1 manure were tested at four soil depths (0–10, 10–20, 20–30, and 30–40 cm). Aggregates were grouped into large macro-aggregates (5–2 mm), small macro-aggregates (2–0.25 mm), micro-aggregates (0.25–0.053 mm) and silt + clay <span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">(&lt;0.053 mm). Biochar, straw,<span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;"> and manure applications all had significant effects (<span style="font-family: TimesNewRomanPS-ItalicMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;"><em>p </em><span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">&lt; 0.05) on aggregate stability, with B<span style="font-family: TimesNewRomanPSMT; font-size: 5pt; color: #231f20; font-style: normal; font-variant: normal;">2 <span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">at<span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;"> 20 cm soil depth showing the greatest increase (62.1%). SB<span style="font-family: TimesNewRomanPSMT; font-size: 5pt; color: #231f20; font-style: normal; font-variant: normal;">1 <span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">of small macro-aggregate fraction<span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;"> showed the highest aggregate proportion (50.59% ± 10.48) at the 20–30 cm soil depth. The highest TOC was observed in SB<span style="font-family: TimesNewRomanPSMT; font-size: 5pt; color: #231f20; font-style: normal; font-variant: normal;">2  <span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">(40.9 g kg<span style="font-family: TimesNewRomanPSMT; font-size: 5pt; color: #231f20; font-style: normal; font-variant: normal;">-1<span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">) of large macro-aggregate at 10–20 cm soil depth. Treatment effects on soil MBC was high, with B<span style="font-family: TimesNewRomanPSMT; font-size: 5pt; color: #231f20; font-style: normal; font-variant: normal;">1 <span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">showing the greatest value (600.0 µg g<span style="font-family: TimesNewRomanPSMT; font-size: 5pt; color: #231f20; font-style: normal; font-variant: normal;">-1<span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;">) at the 20–30<span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;"> cm soil depth. Our results showed that application of biochar, straw, and manure to soil increased<span style="font-family: TimesNewRomanPSMT; font-size: 9pt; color: #231f20; font-style: normal; font-variant: normal;"> aggregate stability, TOC as well as MBC.</span></span></span></span></span></span><br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" /></span></span></span></span></span></span></span></span></span></span></span></span></span></span></p>

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