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

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

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.

Impact of arbuscular mycorrhizal fungi and earthworms on soil aggregate stability, glomalin, and performance of pigeonpea, Cajanus cajan

Soil Research ◽  
2019 ◽  
Vol 57 (1) ◽  
pp. 53 ◽  
Author(s):  
Mary N. Muchane ◽  
Mirjam M. Pulleman ◽  
Bernard Vanlauwe ◽  
Joyce Jefwa ◽  
Thomas W. Kuyper
Keyword(s):  
Mycorrhizal Fungi ◽  
Cajanus Cajan ◽  
Plant Biomass ◽  
Aggregate Size ◽  
Arbuscular Mycorrhizal ◽  
Hyphal Length ◽  
Root Colonisation ◽  
Size Classes ◽  
Crop Performance ◽  
Epigeic Earthworms

Earthworms and arbuscular mycorrhizal fungi (AMF) modify soil physical and chemical properties. However, little is known about how their interactions affect water-stable aggregation, glomalin and crop performance. A greenhouse experiment was run for 9 months to test the effects of earthworms (endogeic, Pontoscolex corethrurus; and epigeic, Dichogaster bolaui) and AMF (none, Glomus etunicatum and Scutellospora verrucosa) on water-stable aggregation, glomalin levels in aggregate size classes and crop performance. The test crop was pigeonpea (Cajanus cajan (L.) Millsp.). The soil material used for the experiment was a humic nitisol from central Kenya mixed with sand (ratio 1:1). Grass residue (equivalent to 20tha–1) was placed on top. The AMF root colonisation and external hyphal length, water-stable macroaggregates and microaggregates, total and easily-extractable glomalin in aggregate size classes, plant biomass and plant N and P uptake were measured. Earthworms were a major source of variation for soil aggregation, glomalin content and crop performance. The epigeic earthworms (D. bolaui) increased the amount of water-stable macroaggregates (by 10%) and glomalin in microaggregates and improved crop (growth and biomass) performance. The endogeic earthworms (P. corethrurus) reduced external hyphal length, root colonisation and crop performance but had no effect on water-stable aggregates and glomalin levels in in aggregate size classes. A significant AMF×earthworm interaction was observed for plant biomass and concentrations of nitrogen (N) and phosphorus (P). The AMF species together with epigeic earthworms increased plant biomass and N and P concentrations. Our results contribute to the understanding of interactions between AMF and earthworms in relation to soil aggregation, plant productivity and nutrient uptake.

Glomalin in aggregate size classes from three different farming systems

2007 ◽  
Vol 94 (2) ◽  
pp. 546-549 ◽  
Author(s):  
S WRIGHT ◽  
V GREEN ◽  
M CAVIGELLI
Keyword(s):  
Aggregate Size ◽  
Farming Systems ◽  
Size Classes

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.

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