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

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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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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Biochar altered native soil organic carbon by changing soil aggregate size distribution and native SOC in aggregates based on an 8-year field experiment

The Science of The Total Environment ◽

10.1016/j.scitotenv.2019.134829 ◽

2020 ◽

Vol 708 ◽

pp. 134829 ◽

Cited By ~ 5

Author(s):

Zhencai Sun ◽

Zhengcheng Zhang ◽

Kun Zhu ◽

Zhimin Wang ◽

Xiaorong Zhao ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Field Experiment ◽

Size Distribution ◽

Aggregate Size ◽

Soil Aggregate ◽

Aggregate Size Distribution ◽

Native Soil

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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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Comments on "Lithology and climate controlled soil aggregate size distribution and organic carbon stability in the Peruvian Andes"

10.5194/soil-2019-40-rc1 ◽

2019 ◽

Author(s):

Anonymous

Keyword(s):

Organic Carbon ◽

Size Distribution ◽

Aggregate Size ◽

Soil Aggregate ◽

Peruvian Andes ◽

Aggregate Size Distribution

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Supplementary material to "Lithology and climate controlled soil aggregate size distribution and organic carbon stability in the Peruvian Andes"

10.5194/soil-2019-40-supplement ◽

2019 ◽

Author(s):

Songyu Yang ◽

Boris Jansen ◽

Samira Absalah ◽

Rutger L. van Hall ◽

Karsten Kalbitz ◽

...

Keyword(s):

Organic Carbon ◽

Size Distribution ◽

Aggregate Size ◽

Soil Aggregate ◽

Peruvian Andes ◽

Aggregate Size Distribution ◽

Supplementary Material

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

International Agrophysics ◽

10.1515/intag-2015-0057 ◽

2015 ◽

Vol 29 (4) ◽

pp. 501-508 ◽

Cited By ~ 2

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.

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