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

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.

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

Soil Research ◽

10.1071/sr9950153 ◽

1995 ◽

Vol 33 (1) ◽

pp. 153 ◽

Cited By ~ 22

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.

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

International Journal of Wildland Fire ◽

10.1071/wf03068 ◽

2004 ◽

Vol 13 (2) ◽

pp. 195 ◽

Cited By ~ 70

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.

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Effect of community-based soil and water conservation practices on soil glomalin, aggregate size distribution, aggregate stability and aggregate-associated organic carbon in northern highlands of Ethiopia

Agriculture & Food Security ◽

10.1186/s40066-018-0193-1 ◽

2018 ◽

Vol 7 (1) ◽

Cited By ~ 3

Author(s):

Mengistu Welemariam ◽

Fassil Kebede ◽

Bobe Bedadi ◽

Emiru Birhane

Keyword(s):

Organic Carbon ◽

Size Distribution ◽

Water Conservation ◽

Aggregate Stability ◽

Aggregate Size ◽

Soil And Water Conservation ◽

Conservation Practices ◽

Community Based ◽

Aggregate Size Distribution ◽

Soil And Water

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

Canadian Journal of Soil Science ◽

10.4141/cjss2010-044 ◽

2012 ◽

Vol 92 (3) ◽

pp. 529-536 ◽

Cited By ~ 35

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.

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

Soil Research ◽

10.1071/sr00018 ◽

2001 ◽

Vol 39 (3) ◽

pp. 465 ◽

Cited By ~ 105

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.

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Potential Benefits of Polymers in Soil Erosion Control for Agronomical Plans: A Laboratory Experiment

Agronomy ◽

10.3390/agronomy9060276 ◽

2019 ◽

Vol 9 (6) ◽

pp. 276 ◽

Cited By ~ 10

Author(s):

Tugrul Yakupoglu ◽

Jesús Rodrigo-Comino ◽

Artemi Cerdà

Keyword(s):

Soil Erosion ◽

Sediment Yield ◽

Soil Aggregates ◽

Aggregate Stability ◽

Aggregate Size ◽

Extreme Rainfall ◽

Rainfall Simulation ◽

Water Losses ◽

Total Runoff ◽

Runoff Sediment

New management and techniques to reduce soil and water losses are necessary to achieve goals related to sustainability and develop useful agronomical plans. Among the strategies to reduce soil losses, the use of polymers has been studied but little is known about the effect of them on soil aggregates under extreme rainfall conditions. The main aim of this study was to compare the effects of polyacrylamide (PAM) and polyvinyl alcohol (PVA) on initial soil erosion process activation. We applied both products on soils and soil aggregate stability was measured on polymer treated and control plots. Laboratory erosion plots (pans) were placed on 15% slope, and sequential simulated rainfalls (under dry and wet conditions) with 360 mm h−1 intensity were applied for 12 min. Time to runoff, total runoff, runoff sediment yield, and splash sediment yield were determined. The results show that polymers do not delay runoff initiation; however, they reduced total runoff, sediment yield, and soil transported by the splash. PVA was not effective in reducing the total runoff during the first rainfall being PAM more effective in this way. However, under the sequential rainfall, both polymers obtained positive results, showing PAM some improvements in comparison to PVA. The effect of the polymer to reduce soil transported by splash after performing the second rainfall simulation was clearly demonstrated, meanwhile the effects during the first simulation were not significant. The effectiveness of the polymers on soil aggregates increased with increasing aggregate size. The application of polymers reached the highest efficiency on aggregates of 6.4 mm in diameter.

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

Polish Journal of Soil Science ◽

10.17951/pjss.2020.53.1.41 ◽

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

A two-year field trial on maize (Zea mays 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 (<0.053 mm). Biochar, straw, and manure applications all had significant effects (p < 0.05) on aggregate stability, with B2 at 20 cm soil depth showing the greatest increase (62.1%). SB1 of small macro-aggregate fraction showed the highest aggregate proportion (50.59% ± 10.48) at the 20–30 cm soil depth. The highest TOC was observed in SB2 (40.9 g kg-1) of large macro-aggregate at 10–20 cm soil depth. Treatment effects on soil MBC was high, with B1 showing the greatest value (600.0 µg g-1) at the 20–30 cm soil depth. Our results showed that application of biochar, straw, and manure to soil increased aggregate stability, TOC as well as MBC.<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;" />

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NOTE ON THE AGGREGATE-SIZE DISTRIBUTION AND AGGREGATE STABILITY IN HALDIMAND CLAY TREATED WITH FOUR SOIL ADDITIVES

Canadian Journal of Soil Science ◽

10.4141/cjss59-031 ◽

1959 ◽

Vol 39 (2) ◽

pp. 254-255

Author(s):

L. R. WEBBER

Keyword(s):

Size Distribution ◽

Aggregate Stability ◽

Aggregate Size ◽

Aggregate Size Distribution ◽

Soil Additives

not available

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The effect of alternate freezing and thawing on aggregate stability and aggregate size distribution of some Prince Edward Island soils

Journal of Soil Science ◽

10.1111/j.1365-2389.1991.tb00401.x ◽

1991 ◽

Vol 42 (2) ◽

pp. 193-204 ◽

Cited By ~ 66

Author(s):

L. M. EDWARDS

Keyword(s):

Size Distribution ◽

Prince Edward Island ◽

Aggregate Stability ◽

Aggregate Size ◽

Freezing And Thawing ◽

Aggregate Size Distribution

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Aggregate and Particle Size Distribution of the Soil Sediment Eroded on Steep Artificial Slopes

Applied Sciences ◽

10.3390/app11104427 ◽

2021 ◽

Vol 11 (10) ◽

pp. 4427

Author(s):

Romana Kubínová ◽

Martin Neumann ◽

Petr Kavka

Keyword(s):

Particle Size ◽

Soil Erosion ◽

Particle Size Distribution ◽

Size Distribution ◽

Soil Aggregates ◽

Aggregate Size ◽

Soil Particle ◽

Initial State ◽

Erosion Processes ◽

Soil Sediment

In this study, the particle size distribution (PSD) of the soil sediment from topsoil obtained from soil erosion experiments under different conditions was measured. Rainfall simulators were used for rain generation on the soil erosion plots with slopes 22°, 30°, 34° and length 4.25 m. The influence of the external factors (slope and initial state) on the particle and aggregate size distribution were evaluated by laser diffractometer (LD). The aggregate representation percentage in the eroded sediment was also investigated. It has been found that when the erosion processes are intensive (steep slope or long duration of the raining), the eroded sediment contains coarser particles and lower amounts of aggregates. Three methods for the soil particle analyses were tested: (i) conventional–sieving and hydrometer method; (ii) PARIO Soil Particle Analyzer combined with sieving; and (iii) laser diffraction (LD) using Mastersizer 3000. These methods were evaluated in terms of reproducibility of the results, time demands, and usability. It was verified that the LD has significant advantages compared to other two methods, especially the short measurement time for one sample (only 15 min per sample for LD) and the possibility to destroy soil aggregates using ultrasound which is much easier than using hexametaphosphate.

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