Responses of soil labile organic carbon and water-stable aggregates to reforestation in southern subtropical China

2020 ◽  
Author(s):  
Yuanqi Chen ◽  
Yu Zhang ◽  
Shiqin Yu ◽  
Feng Li ◽  
Suping Liu ◽  
...  
Keyword(s):  
Forest Type ◽  
Aggregate Size ◽  
Species Selection ◽  
Subtropical China ◽  
Organic C ◽  
Soil Layers ◽  
Soil C ◽  
Size Classes ◽  
Water Stable Aggregates ◽  
Doc Concentration

Abstract Aims Reforestation can enhance soil carbon (C) stability and promote soil C accumulation. Experimental results are, however, highly variable, and the efficacy of reforestation in enhancing soil C stability is still in debate. Consequently, it remains unclear how the different soil C pools respond to reforestation in forest ecosystems. Methods The response of different soil C fractions to reforestation was examined in five subtropical forests, including the plantations of Eucalyptus urophylla (EU), Acacia crassicapa (AC), Castanopsis hystrix (CH), and 10-species mixed (MX), and a naturally recovered shrubland (NS). Soil labile C fractions (readily oxidized organic C by KMnO4: ROC; dissolved organic C: DOC), distribution of aggregate-size classes and aggregate-associated C from different soil layers (0-10, 10-20, 20-40 and 40-60 cm) were evaluated. Important Findings We found that reforestation and forest type did not affect ROC concentration, yet the highest DOC concentration was detected in NS at four soil layers. Aggregate C concentration was the highest in all aggregate-size classes of CH at 0-10 cm depth. In addition, forest type did not alter the proportion of soil water-stable aggregates at four soil layers. However, soil depths significantly affected the distribution of soil aggregates with >0.25 mm aggregates dominating in the top soils (0-20 cm), but 0.053-2 mm aggregates being dominant in the deep soils (20-60 cm). These results indicate that reforestation and forest type affectes soil DOC (0-60 cm) and aggregate C (0-10 cm). Furthermore, soil DOC and aggregate C were more susceptive to reforestation than ROC. The findings suggest that plantations reduce soil DOC concentration, highlighting that C leaching loss may decrease compared with natural recovery. Moreover, C. hystrix plantation may enhance soil C stability by physical protection in topsoil. This study provides valuable information on tree species selection for reforestation concerning soil C sequestration in southern subtropical China.

Quality of soil from the nickel mining area of Southeast Sulawesi, Indonesia, engineered using earthworms (Pheretima sp.)

2021 ◽  
Vol 8 (4) ◽  
pp. 2995-3005
Author(s):  
Hasbullah Syaf ◽  
Muhammad Albar Pattah ◽  
Laode Muhammad Harjoni Kilowasid
Keyword(s):  
Tap Water ◽  
Soil Aggregates ◽  
Aggregate Size ◽  
Mining Area ◽  
Size Class ◽  
Soil Conditions ◽  
Total N ◽  
Organic C ◽  
Size Classes ◽  
Nickel Mining

Earthworms (Pheretima sp.) could survive under abiotic stress soil conditions. Furthermore, their activities as ecosystem engineers allow for the creation of soil biostructures with new characteristics. Therefore, this study aimed to investigate the effect of the abundance of Pheretima sp. on the aggregate size, physicochemistry, and biology of the topsoil from the nickel mining area of Southeast Sulawesi, Indonesia. It was carried out by first grouping their abundance into zero, two, four, six, and eight individuals per pot and then carrying out tests. The Pheretima sp. were then released onto the surface of the topsoil and mixed with biochar that was saturated with tap water in the pot overnight. The results showed that the abundance of the species had a significant effect on the size class distribution, and aggregate stability of the soil. Furthermore, the size of the soil aggregates formed was dominated by the size class 2.83 - 4.75 mm under both dry and wet conditions. Under dry conditions, three size classes were found, while under wet conditions, there were five size classes. The results also showed that the highest and lowest stability indexes occurred with zero and eight Pheretima sp., respectively. Furthermore, the abundance had a significant effect on pH, organic C, total N, CEC, and total nematodes. However, it had no significant effect on the total P, C/N ratio, total AMF spores, and flagellate. The highest soil pH occurred with zero Pheretima sp., while with six and two members of the species, the total nematode was at its highest and lowest populations, respectively. Therefore, it could be concluded that the species was able to create novel conditions in the topsoils at the nickel mining area that were suitable for various soil biota.

Soil acidification and the carbon cycle in a cropping soil of north-eastern Victoria

Soil Research ◽  
1998 ◽  
Vol 36 (2) ◽  
pp. 273 ◽  
Author(s):  
W. J. Slattery ◽  
D. G. Edwards ◽  
L. C. Bell ◽  
D. R. Coventry ◽  
K. R. Helyar
Keyword(s):  
Soil Depth ◽  
Organic C ◽  
Soil Layers ◽  
Soil C ◽  
Soil Zone ◽  
North Eastern ◽  
Soil Buffering ◽  
The Impact ◽  
Total Organic C

Changes in soil organic matter were determined for a long-term (1975–95) experiment at the Rutherglen Research Institute in north-eastern Victoria. The crop rotations in this experiment were continuous lupins (LL) and continuous wheat (WW). The soil at this site was a solodic or Yellow Dermosol with a soil pH of 6·08 (pH in 0·01 М CaCl2 1 : 5) in 1975 in the surface 10 cm, which had declined by 0·8 and 1·5 pH units for WW and LL, respectively, in the 0–20 cm soil zone by 1992. Acidification rates decreased with increasing soil depth. The acidification rate in the 0–60 cm soil zone was 12·5 kmol(H+)/ha·year for the LL rotation and 4·6 kmol(H+)/ha·year for the WW rotation. The amount of CaCO3 required to neutralise the acidification of wheat-lupin rotations as calculated in this paper was up to 3·8 t/ha ·10 years for a WLWL rotation or 3 ·3 t/ha ·10 years for a WWL rotation; these amounts are significantly higher than previously reported rates. In this paper, we calculate the impact of changes in soil carbon (C) status over time, and therefore soil buffering, on the rates of acidification in incremental soil layers to a depth of 60 cm. Total organic C for these rotations in 1992 was 1·12% for WW and 1·17% for LL in the 0–10 cm soil zone. An investigation of the humic and fulvic acid fractions of these 2 rotations to a depth of 60 cm showed that the LL rotation had significantly higher (P < 0·05) C at depth than the WW rotation. Acidification due to the net decrease in soil C over the 15-year study period plus acidification due to the alkali removed in the seed was calculated to be –4·88 kmol(H+)/ha·year for the LL rotation and –6·52 kmol(H+)/ha·year for the WW rotation.

scholarly journals Effects of reclamation years on composition and diversity of soil bacterial communities in Northwest China

2018 ◽  
Vol 64 (1) ◽  
pp. 28-40 ◽  
Author(s):  
Zhibo Cheng ◽  
Fenghua Zhang ◽  
William Jeffrey Gale ◽  
Weichao Wang ◽  
Wen Sang ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Phylogenetic Diversity ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Soil Electrical Conductivity ◽  
Soil Organic C ◽  
Organic C ◽  
Size Classes ◽  
Soil Bacterial Communities ◽  
Soil Bacterial

The objective of this study was to evaluate bacterial community structure and diversity in soil aggregate fractions when salinized farmland was reclaimed after >27 years of abandonment and then farmed again for 1, 5, 10, and 15 years. Illumina MiSeq high-throughput sequencing was performed to characterize the soil bacterial communities in 5 aggregate size classes in each treatment. The results indicated that reclamation significantly increased macro-aggregation (>0.25 mm), as well as soil organic C, available N, and available P. The 10-year field had the largest proportion (93.9%) of soil in the macro-aggregate size classes (i.e., >0.25 mm) and the highest soil electrical conductivity. The 5 most dominant phyla in the soil samples were Proteobacteria, Actinobacteria, Gemmatimonadetes, Acidobacteria, and Bacteroidetes. The phylogenetic diversity, Chao1, and Shannon indices increased after the abandoned land was reclaimed for farming, reaching maximums in the 15-year field. Among aggregate size classes, the 1–0.25 mm aggregates generally had the highest phylogenetic diversity, Chao1, and Shannon indices. Soil organic C and soil electrical conductivity were the main environmental factors affecting the soil bacterial communities. The composition and structure of the bacterial communities also varied significantly depending on soil aggregate size and time since reclamation.

Soil aggregate stability and soil organic matter fractions under agropastoral systems established in native savanna

Soil Research ◽  
1996 ◽  
Vol 34 (6) ◽  
pp. 891 ◽  
Author(s):  
AJ Gijsman
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Soil Disturbance ◽  
N Content ◽  
Soil C ◽  
Size Classes ◽  
Soil C And N ◽  
C And N

An area of native savanna on an Oxisol in the Eastern Plains of Colombia was opened and sown to various rotations of grass or grass-legume pasture with rice. After 4.5 years, the soil was sampled for studying the effect of land conversion on soil aggregation and on the distribution of total and particulate soil organic matter across the aggregate size classes. The size distribution of undisturbed aggregates did not vary among treatments. Five different methods were used to measure wet aggregate stability (WAS). The choice of method affected the WAS average across treatments as well as the differences among treatments. The only consistent observation was the lower WAS under monocropped rice compared with the other treatments. Inclusion of a legume in a pasture hardly affected aggregate stability. In contrast to the WAS measurements, which were carried out with soil aggregates of 1-2 mm, wet sieving of whole-soil samples revealed additional differences among treatments: large macroaggregates (>2 mm) proved less stable under those treatments that involved soil disturbance through ploughing and harvesting. Total soil C and N content did not vary among treatments, despite considerable differences in plant production levels. The C concentration, but not the N concentration, declined with decreasing aggregate size. The distribution of whole-soil C and N content across aggregate size classes depended more on the amount of soil in a certain size class than on the size class's C or N concentration. Those treatments that involved frequent soil disturbance had a smaller fraction of large macroaggregates (>2 mm) and, as a consequence, less C and N in the large macroaggregate fraction. The particulate organic matter (POM) fraction accounted for only 6.2-8.5% of total soil carbon. The small size of this pool makes it unlikely that POM can serve in these Oxisols for estimating the amount of soil organic matter with medium turnover rate, as suggested by others.

Redox-driven changes in the distribution of Fe minerals between aggregate-size classes in illuvial and elluvial horizons of a hydromorphic soil

2021 ◽  
Author(s):  
Beatrice Giannetta ◽  
Danilo Oliveira De Souza ◽  
Giuliana Aquilanti ◽  
Daniel Said Pullicino
Keyword(s):  
Particle Size ◽  
Clay Fraction ◽  
Aggregate Size ◽  
Redox Cycling ◽  
Paddy Soils ◽  
Organic C ◽  
X Ray ◽  
Size Classes ◽  
Particle Size Classes

&lt;div&gt; &lt;p&gt;&lt;span&gt;Paddy soils experience long-term redox alternations affecting the interactions between the biogeochemical cycling of iron (Fe) and carbon (C). Although the higher soil organic matter (SOM) accumulation rates in paddy topsoils with respect to non-paddy soils is generally assumed to be due to limited mineralization under anoxic soil conditions resulting from frequent field flooding, there is growing evidence questioning this assumption. Moreover, differences in particle aggregation and SOM turnover are likely to both affect and be affected by the trajectory of Fe mineral evolution/crystallinity with redox fluctuations. We hypothesized that redox cycling in paddy soils will affect the particle aggregation, the distribution and mineralogy Fe (hydr)oxides between aggregate size fractions, and consequently the mechanisms of SOM stabilization. In particular, we expect finer aggregate and particle size classes to have a higher proportion of short-range ordered (SRO) Fe oxides with respect to larger aggregates under paddy management, compared to non-paddy management, and that paddy management can result in lower amounts of Fe(hydr)oxides in the topsoil with respect to non-paddy soils. &lt;/span&gt;&lt;span&gt;&amp;#160;&lt;/span&gt;&lt;/p&gt; &lt;/div&gt;&lt;div&gt; &lt;p&gt;&lt;span&gt;We tested these hypotheses by evaluating mineralogical changes, and the distribution of Fe species and organic C between different aggregate and particle-size fractions in topsoil (eluvial) and subsoil (illuvial) horizons of soils under long-term paddy (P) horizons (Arp1, Arp2, Arpd, Brd1, Brd2) and non-paddy (NP) horizons (Ap1, Ap2, Bgw) in NW Italy. Soil aggregates (microaggregates: &lt;200&amp;#160;&lt;/span&gt;&lt;span&gt;&amp;#956;&lt;/span&gt;&lt;span&gt;m, free silt: (53-2 &lt;/span&gt;&lt;span&gt;&amp;#956;&lt;/span&gt;&lt;span&gt;m), free clay: &lt;2 &lt;/span&gt;&lt;span&gt;&amp;#956;&lt;/span&gt;&lt;span&gt;m, and, after sonication, fine sand, silt and clay within microaggregates) have been obtained from&lt;/span&gt;&lt;span&gt;bulk soils using an aggregate and particle size physical fractionation method. After fractionation, Fe phases were evaluated by selective extraction procedures, X-ray diffraction (XRD) and Fe K-edge extended X-ray fine structure (Fe EXAFS) spectroscopy (Elettra XAFS beamline). &lt;/span&gt;&lt;/p&gt; &lt;/div&gt;&lt;div&gt; &lt;p&gt;Our results indicate: (1) a &lt;span&gt;depletion in the contents of ferrihydrite in the P topsoil horizons with respect to NP, though redox cycling favoured an increase in ferrihydrite in the P subsoil, possibly due to Fe(II) translocation from topsoil to subsoil, with consequent ferrihydrite precipitation and aggregates formation; &lt;/span&gt;(2) more crystalline Fe mineral phases were associated with intra-aggregate clay fraction in the P topsoil&lt;span&gt;. In the clay fraction in the Brd2 subsoil horizon &lt;/span&gt;magnetite was observed. &lt;span&gt;In the NP soil the illuvial horizons were not characterized by a significant increase in ferrihydrite. Our hypothesis that finer aggregate and particle size classes have a higher proportion of SRO Fe oxides with respect to larger aggregates under P management, with respect to NP management,&amp;#160;&lt;/span&gt;was confirmed; (3) more organic C was associated with the fine fraction in P with respect to NP suggesting that redox cycling enhances the chemical stabilization of mineral-associated SOM.&lt;/p&gt; &lt;/div&gt;&lt;div&gt; &lt;p&gt;These findings focused on localized Fe dynamics and biogeochemical coupling with SOM, suggesting that &lt;span&gt;redox-driven changes in aggregate-size classes distribution were also linked to the differences in organic C and Fe stocks in these two agro-ecosystems.&lt;/span&gt;&lt;/p&gt; &lt;/div&gt;

Labile organic C and N mineralization of soil aggregate size classes in semiarid grasslands as affected by grazing management

2011 ◽  
Vol 48 (3) ◽  
pp. 305-313 ◽  
Author(s):  
Honghui Wu ◽  
Martin Wiesmeier ◽  
Qiang Yu ◽  
Markus Steffens ◽  
Xinguo Han ◽  
...  
Keyword(s):  
N Mineralization ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Grazing Management ◽  
Organic C ◽  
Size Classes ◽  
C And N Mineralization ◽  
C And N

Divergent effects of snow exclusion on microbial variables across aggregate size classes

CATENA ◽  
2021 ◽  
Vol 206 ◽  
pp. 105481
Author(s):  
Kaijun Yang ◽  
Rui Yin ◽  
Josep Peñuelas ◽  
Zhijie Li ◽  
Bo Tan ◽  
...  
Keyword(s):  
Aggregate Size ◽  
Size Classes

Manipulation of rhizosphere organisms to enhance glomalin production and C sequestration: Pitfalls and promises

2014 ◽  
Vol 94 (6) ◽  
pp. 1025-1032 ◽  
Author(s):  
F. L. Walley ◽  
A. W. Gillespie ◽  
Adekunbi B. Adetona ◽  
J. J. Germida ◽  
R. E. Farrell
Keyword(s):  
Plant Growth ◽  
Mycorrhizal Fungi ◽  
Plant Growth Promoting Rhizobacteria ◽  
C Sequestration ◽  
Ionization Mass ◽  
Edge Structure ◽  
Organic C ◽  
Soil C ◽  
N Storage ◽  
C And N

Walley, F. L., Gillespie, A. W., Adetona, A. B., Germida, J. J. and Farrell, R. E. 2014. Manipulation of rhizosphere organisms to enhance glomalin production and C-sequestration: Pitfalls and promises. Can. J. Plant Sci. 94: 1025–1032. Arbuscular mycorrhizal fungi (AMF) reportedly produce glomalin, a glycoprotein that has the potential to increase soil carbon (C) and nitrogen (N) storage. We hypothesized that interactions between rhizosphere microorganisms, such as plant growth-promoting rhizobacteria (PGPR), and AMF, would influence glomalin production. Our objectives were to determine the effects of AMF/PGPR interactions on plant growth and glomalin production in the rhizosphere of pea (Pisum sativum L.) with the goal of enhancing C and N storage in the rhizosphere. One component of the study focussed on the molecular characterization of glomalin and glomalin-related soil protein (GRSP) using complementary synchrotron-based N and C X-ray absorption near-edge structure (XANES) spectroscopy, pyrolysis field ionization mass spectrometry (Py-FIMS), and proteomics techniques to characterize specific organic C and N fractions associated with glomalin production. Our research ultimately led us to conclude that the proteinaceous material extracted, and characterized in the literature, as GRSP is not exclusively of AMF origin. Our research supports the established concept that GRSP is important to soil quality, and C and N storage, irrespective of origin. However, efforts to manipulate this important soil C pool will remain compromised until we more clearly elucidate the chemical nature and origin of this resource.

Carbon and nutrient mineralisation dynamics in aggregate-size classes from different tillage systems after input of canola and wheat residues

2018 ◽  
Vol 116 ◽  
pp. 22-38 ◽  
Author(s):  
Jharna Rani Sarker ◽  
Bhupinder Pal Singh ◽  
Annette L. Cowie ◽  
Yunying Fang ◽  
Damian Collins ◽  
...  
Keyword(s):  
Aggregate Size ◽  
Tillage Systems ◽  
Size Classes ◽  
Nutrient Mineralisation

Soil organic carbon stocks under different páramo vegetation covers in Ecuador’s northern Andes

2021 ◽  
Author(s):  
Marlon Calispa ◽  
Raphaël van Ypersele ◽  
Benoît Pereira ◽  
Sebastián Páez-Bimos ◽  
Veerle Vanacker ◽  
...  
Keyword(s):  
Volcanic Ash ◽  
Vegetation Type ◽  
Regional Scale ◽  
Soil Samples ◽  
Related Factors ◽  
Organic C ◽  
Soil C ◽  
C Storage ◽  
Soc Stocks ◽  
Volcanic Ash Soils

&lt;p&gt;The Ecuadorian p&amp;#225;ramo, a neotropical ecosystem located in the upper Andes, acts as a constant source of high-quality water. It also stores significant amounts of C at the regional scale. In this region, volcanic ash soils sustain most of the paramo, and C storage results partly from their propensity to accumulate organic matter. Vegetation type is known to influence the balance between plant C inputs and soil C losses, ultimately affecting the soil organic C (SOC) content and stock. Tussock-forming grass (spp. Calamagrostis Intermedia; TU), cushion-like plants (spp. Azorella pedunculata; CU) and shrubs and trees (Polylepis stands) are commonly found in the p&amp;#225;ramo. Our understanding of SOC stocks and dynamics in the p&amp;#225;ramo remains limited, despite mounting concerns that human activities are increasingly affecting vegetation and potentially, the capacity of these ecosystems to store C.&lt;/p&gt;&lt;p&gt;Here, we compare the organic C content and stock in soils under tussock-forming grass (spp. Calamagrostis Intermedia; TU) and soils under cushion-like plants (spp. Azorella pedunculata; CU). The study took place at Jatunhuayco, a watershed on the western slopes of Antisana volcano in the northern Ecuadorian Andes. Two areas of similar size (~0.35 km&lt;sup&gt;2&lt;/sup&gt;) were surveyed. Fourty soil samples were collected randomly in each area to depths varying from 10 to 30 cm (A horizon) and from 30 to 75 cm (2Ab horizon). The soils are Vitric Andosols and the 2Ab horizon corresponds to a soil buried by the tephra fall from the Quilotoa eruption about 800 yr. BP. Sixteen intact soil samples were collected in Kopecky's cylinders for bulk density (BD) determination of each horizon.&lt;/p&gt;&lt;p&gt;The average SOC content in the A horizon of the CU sites (9.4&amp;#177;0.5%) is significantly higher (Mann-Whitney U test, p&lt;0.05) than that of the TU sites (8.0&amp;#177;0.4%), probably reflecting a larger input of root biomass from the cushion-forming plants. The 2Ab horizon contains less organic C (i.e. TU: 4.3&amp;#177;0.3% and CU: 4.0&amp;#177;0.4%) than the A horizon, but the SOC contents are undistinguishable between the two vegetation types. This suggests that the influence of vegetation type on SOC is limited to the A horizon. The average SOC stocks (in the first 30 cm from the soil) for TU and CU are 20.04&amp;#177;1.1 and 18.23&amp;#177;1.0 kg/m&lt;sup&gt;2&lt;/sup&gt;,&lt;sup&gt;&lt;/sup&gt;respectively. These values are almost two times greater than the global average reported for Vitric Andosols (~8.2 kg/m&lt;sup&gt;2&lt;/sup&gt;&amp;#160;), but are lower than the estimates obtained for some wetter Andean p&amp;#225;ramos (22.5&amp;#177;5 kg/m&lt;sup&gt;2&lt;/sup&gt;, 270% higher rainfall) from Ecuador. Our stock values further indicate that vegetation type has a limited effect on C storage in the young volcanic ash soils found at Jatunhuyaco. Despite a higher SOC content, the CU soils store a stock of organic C similar to that estimated for the TU soils. This likely reflects the comparatively lower BD of the former soils (650&amp;#177;100 vs. 840&amp;#177;30 kg/m&lt;sup&gt;3&lt;/sup&gt;). Additional studies are needed in order to establish the vegetation-related factors driving the SOC content and stability in the TU and CU soils.&lt;/p&gt;

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