Microbial biomass and soil organic carbon accumulation on a former lakebed near Novosibirsk, Russia

2016 ◽  
Vol 179 (2) ◽  
pp. 190-192 ◽  
Author(s):  
Mikhail. V. Yakutin ◽  
L. Anopchenko ◽  
F. Conen
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Accumulation

scholarly journals The Contribution of Microorganisms to Soil Organic Carbon Accumulation under Fertilization Varies among Aggregate Size Classes

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2126
Author(s):  
Jinjing Lu ◽  
Shengping Li ◽  
Guopeng Liang ◽  
Xueping Wu ◽  
Qiang Zhang ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Aggregate Size ◽  
Carbon Accumulation ◽  
Community Diversity ◽  
C Storage ◽  
Soil Aggregate Fractions

Long-term fertilization alters soil microbiological properties and then affects the soil organic carbon (SOC) pool. However, the interrelations of SOC with biological drivers and their relative importance are rarely analyzed quantitatively at aggregate scale. We investigated the contribution of soil microbial biomass, diversity, and enzyme activity to C pool in soil aggregate fractions (>5 mm, 2–5 mm, 1–2 mm, 0.25–1 mm, and <0.25 mm) at topsoil (0–15 cm) from a 27-year long-term fertilization regime. Compared to CK (no fertilization management), NP (inorganic fertilization alone) decreased all of the microbial groups’ biomass, while NPS and NPM (inorganic fertilization plus the incorporation of maize straw or composted cow manure) significantly reduced this negative effect of NP on microbial biomass and increased the microbial contribution to C pool. The results show that microbial variables were significantly correlated with SOC content in >0.25 mm aggregates rather than in <0.25 mm aggregates. Fungal variables (fungal, AM biomass, and F/B ratio) and enzyme activities (BXYL and LAP) in >0.25 mm aggregates explained 21% and 2% of C, respectively. Overall, organic matter addition could contribute to higher C storage by boosting fungal community and enzyme activity rather than by changing microbial community diversity in macro-aggregates.

scholarly journals Organic mulching promotes soil organic carbon accumulation to deep soil layer in an urban plantation forest

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaodan Sun ◽  
Gang Wang ◽  
Qingxu Ma ◽  
Jiahui Liao ◽  
Dong Wang ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Fine Roots ◽  
Soil Layer ◽  
Carbon Accumulation ◽  
Bulk Soil ◽  
Organic Mulch ◽  
The Impact ◽  
Soc Fractions

Abstract Background Soil organic carbon (SOC) is important for soil quality and fertility in forest ecosystems. Labile SOC fractions are sensitive to environmental changes, which reflect the impact of short-term internal and external management measures on the soil carbon pool. Organic mulching (OM) alters the soil environment and promotes plant growth. However, little is known about the responses of SOC fractions in rhizosphere or bulk soil to OM in urban forests and its correlation with carbon composition in plants. Methods A one-year field experiment with four treatments (OM at 0, 5, 10, and 20 cm thicknesses) was conducted in a 15-year-old Ligustrum lucidum plantation. Changes in the SOC fractions in the rhizosphere and bulk soil; the carbon content in the plant fine roots, leaves, and organic mulch; and several soil physicochemical properties were measured. The relationships between SOC fractions and the measured variables were analysed. Results The OM treatments had no significant effect on the SOC fractions, except for the dissolved organic carbon (DOC). OM promoted the movement of SOC to deeper soil because of the increased carbon content in fine roots of subsoil. There were significant correlations between DOC and microbial biomass carbon and SOC and easily oxidised organic carbon. The OM had a greater effect on organic carbon fractions in the bulk soil than in the rhizosphere. The thinnest (5 cm) mulching layers showed the most rapid carbon decomposition over time. The time after OM had the greatest effect on the SOC fractions, followed by soil layer. Conclusions The frequent addition of small amounts of organic mulch increased SOC accumulation in the present study. OM is a potential management model to enhance soil organic matter storage for maintaining urban forest productivity.

scholarly journals Soil age and soil organic carbon content shape biochemical responses to multiple freeze–thaw events in soils along a postmining agricultural chronosequence

2021 ◽  
Author(s):  
Christoph Rosinger ◽  
Michael Bonkowski
Keyword(s):  
Microbial Biomass ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Carbon Content ◽  
Organic Carbon Content ◽  
Freeze Thaw ◽  
Biochemical Responses ◽  
Microbial Responses ◽  
Soil Age ◽  
Carbon Losses

AbstractFreeze–thaw (FT) events exert a great physiological stress on the soil microbial community and thus significantly impact soil biogeochemical processes. Studies often show ambiguous and contradicting results, because a multitude of environmental factors affect biogeochemical responses to FT. Thus, a better understanding of the factors driving and regulating microbial responses to FT events is required. Soil chronosequences allow more focused comparisons among soils with initially similar start conditions. We therefore exposed four soils with contrasting organic carbon contents and opposing soil age (i.e., years after restoration) from a postmining agricultural chronosequence to three consecutive FT events and evaluated soil biochgeoemical responses after thawing. The major microbial biomass carbon losses occurred after the first FT event, while microbial biomass N decreased more steadily with subsequent FT cycles. This led to an immediate and lasting decoupling of microbial biomass carbon:nitrogen stoichiometry. After the first FT event, basal respiration and the metabolic quotient (i.e., respiration per microbial biomass unit) were above pre-freezing values and thereafter decreased with subsequent FT cycles, demonstrating initially high dissimilatory carbon losses and less and less microbial metabolic activity with each iterative FT cycle. As a consequence, dissolved organic carbon and total dissolved nitrogen increased in soil solution after the first FT event, while a substantial part of the liberated nitrogen was likely lost through gaseous emissions. Overall, high-carbon soils were more vulnerable to microbial biomass losses than low-carbon soils. Surprisingly, soil age explained more variation in soil chemical and microbial responses than soil organic carbon content. Further studies are needed to dissect the factors associated with soil age and its influence on soil biochemical responses to FT events.

scholarly journals Soil organic carbon accumulation and carbon dioxide emissions during a 6-year study in irrigated continuous maize under two tillage systems in semiarid Mediterranean conditions

2021 ◽  
Vol 19 (1) ◽  
pp. e1102
Author(s):  
Maroua Dachraoui ◽  
Aurora Sombrero
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Temperature ◽  
Grain Yield ◽  
Co2 Emissions ◽  
Carbon Dioxide Emissions ◽  
Carbon Accumulation ◽  
No Tillage ◽  
Short Term ◽  
The Impact

Aim of study: To evaluate the effects of conventional tillage (CT) and no tillage (NT) systems on the soil organic carbon (SOC) changes, CO2 emissions and their relation with soil temperature and grain yield in a monoculture of irrigated maize during six years.Area of study: In Zamadueñas experimental field in the Spanish province of Valladolid, from 2011 to 2017.Material and methods: The SOC content was determined by collecting soil samples up to 30 cm in November at two years interval. Short-term CO2 emissions were measured simultaneously with soil temperature using a respiration chamber and a hand-held probe immediately before, after every tillage operation and during the maize cycle.Main results: The SOC stock of the top 30 cm soil layers was 13% greater under NT than CT. Short-term CO2 emissions were significantly higher under CT ranging from 0.8 to 3.4 g CO2 m-2 h-1 immediately after tillage while under NT system, soil CO2 fluxes were low and stable during this study period. During the first 48 h following tillage, cumulative CO2 emissions ranged from 0.6 to 2.4 Mg CO2 ha-1 and from 0.2 to 0.3 Mg CO2 ha-1 under CT and NT systems, respectively. Soil temperature did not show significant correlation with CO2 emissions; however, it depended mostly on the time of measurement.Research highlights: No tillage increased the SOC accumulation in the topsoil layer, reduced CO2 emissions without decreasing maize grain yield and minimized the impact on climate change compared to CT system.

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