Organic Carbon Stocks Evaluation After Three Years of No-Tillage Practice in a Vertisol, Northern Tunisia

Soil disturbance and disruption is assumed to enhance mineralisation and cause losses of soil organic carbon. Therefore, no tillage is promoted as soil carbon sequestration measure. However, the experimental evidence of enhanced carbon turnover due to soil disturbance is rare.&#160; We investigated soil disturbance in forest ecosystems with simulated bioturbation of wild boar. Wild boar are effective at mixing and grubbing in the soil and wild boar populations are increasing dramatically in many parts of the world. In a six-year field study, we investigated the effect of wild boar bioturbation on the stocks and stability of soil organic carbon in two forest areas at 23 plots. The organic layer and mineral soil down to 15 cm depth were sampled in the disturbed plots and adjacent undisturbed reference plots.No significant changes in soil organic carbon stocks were detected in the bioturbation plots compared with non-disturbed reference plots. However, around 50% of forest floor carbon was transferred with bioturbation to mineral soil carbon and the stock of stabilised mineral-associated carbon increased by 28%. Thus, a large proportion of the labile carbon in the forest floor was transformed into more stable carbon. Carbon saturation of mineral surfaces was not detected, but carbon loading per unit mineral surface increased by on average 66% due to bioturbation. This indicates that mineral forest soils have non-used capacity to stabilise and store more carbon.Our results indicate that soil disturbance and bioturbation alone does not affect soil carbon turnover and stocks, but only change the distribution of carbon in the soil profile. This is in line with results from no-tillage experiments. The prevailing effect is a redistribution of carbon in the soil profile with no changes in total soil carbon stocks. We discuss these findings in the light of soils as potential sinks for carbon.&#160;

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No-tillage and nitrogen application affects the decomposition of 15N-labelled wheat straw and the levels of mineral nitrogen and organic carbon in a Vertisol

Australian Journal of Experimental Agriculture ◽

10.1071/ea06118 ◽

2007 ◽

Vol 47 (7) ◽

pp. 862 ◽

Cited By ~ 9

Author(s):

R. C. Dalal ◽

W. M. Strong ◽

J. E. Cooper ◽

A. J. King

Keyword(s):

Organic Carbon ◽

Wheat Straw ◽

Residence Time ◽

Mean Residence Time ◽

No Tillage ◽

Tillage Practice ◽

Straw Decomposition ◽

Mineral N ◽

Organic C ◽

C And N

No-tillage (NT) practice, where straw is retained on the soil surface, is increasingly being used in cereal cropping systems in Australia and elsewhere. Compared to conventional tillage (CT), where straw is mixed with the ploughed soil, NT practice may reduce straw decomposition, increase nitrogen immobilisation and increase organic carbon in the soil. This study examined 15N-labelled wheat straw (stubble) decomposition in four treatments (NT v. CT, with N rates of 0 and 75 kg/ha.year) and assessed the tillage and fertiliser N effects on mineral N and organic C and N levels over a 10-year period in a field experiment. NT practice decreased the rate of straw decomposition while fertiliser N application increased it. However, there was no tillage practice × N interaction. The mean residence time of the straw N in soil was more than twice as long under the NT (1.2 years) as compared to the CT practice (0.5 years). In comparison, differences in mean residence time due to N fertiliser treatment were small. However, tillage had generally very little effect on either the amounts of mineral N at sowing or soil organic C (and N) over the study period. While application of N fertiliser increased mineral N, it had very little effect on organic C over a 10-year period. Relatively rapid decomposition of straw and short mean residence time of straw N in a Vertisol is likely to have very little long-term effect on N immobilisation and organic C level in an annual cereal cropping system in a subtropical, semiarid environment. Thus, changing the tillage practice from CT to NT may not necessitate additional N requirement unless use is made of additional stored water in the soil or mineral N loss due to increased leaching is compensated for in N supply to crops.

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Soil organic carbon in no-tillage systems of different ages in Southwest Mato Grosso, Brazil

Revista Brasileira de Engenharia Agrícola e Ambiental ◽

10.1590/1807-1929/agriambi.v25n4p250-255 ◽

2021 ◽

Vol 25 (4) ◽

pp. 250-255

Author(s):

Renata M. Severiano ◽

Maria A. P. Pierangeli ◽

Nilton de S. Santos ◽

Vinícius Xavier

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Bulk Density ◽

Soil Bulk Density ◽

Carbon Stocks ◽

Native Vegetation ◽

No Tillage ◽

Tillage Systems ◽

Mato Grosso ◽

Tillage System

ABSTRACT The objectives of this study were to evaluate the effect of the no-tillage system on soil bulk density, soil organic carbon, and carbon stocks in Plinthic subgroups and Oxisols, located in Pontes and Lacerda, State of Mato Grosso, Brazil. The treatments were native vegetation and no-tillage systems established for 3, 8, 10, and 12 years. To analyse soil organic carbon, soils were sampled in each area, with three repetitions, at layers of 0-0.05; 0.05-0.10; 0.10-0.20; 0.20-0.40; 0.40-0.60; 0.60-1.00; 1.00-1.50 and 1.50-2.00 m. For soil bulk density, undisturbed samples were collected at layers of 0-0.20 and 0.20-0.40 m. Compared with areas of native vegetation, soil bulk density values after 12 years increased by 25% in Oxisols and 30% in the Plinthic subgroups. In Oxisols and Plinthic subgroups, respectively, organic carbon concentration was, on average, 20.57, 25.04 g kg-1 under native vegetation; 16.82, 16.59 g kg-1 after 3 years of no-tillage; 13.31, 4.96 g kg-1 after 8 years; 16.52, 14.39 g kg-1 after 10 years; and 17.97, 18.53 g kg-1 after 12 years. In both soils, the no-tillage system contributed to an increase in carbon stocks over the years, but not at depth, being generally limited to the top 0.20 m of the soils. Compared to native vegetation, after 12 years of no-tillage, carbon stocks decreased at a rate of 0.075 Mg ha-1 year-1 in the Plinthic subgroups and increased by 2.3 Mg ha-1 year-1 in Oxisols.

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Glomalin and Contribution of Glomalin to Carbon Sequestration in Soil: A Review

Turkish Journal of Agriculture - Food Science and Technology ◽

10.24925/turjaf.v9i1.191-196.3803 ◽

2021 ◽

Vol 9 (1) ◽

pp. 191-196

Author(s):

MD. Belal Hossain

Keyword(s):

Carbon Sequestration ◽

Organic Carbon ◽

Mycorrhizal Fungi ◽

Tropical Rainforest ◽

Global Environmental Change ◽

Soil Layer ◽

Aggregate Stability ◽

Primary Forest ◽

No Tillage ◽

Tillage Practice

Arbuscular mycorrhizal fungi (AMF) improves the uptake of nutrients and water to the plants through mutual symbiosis. Only AMF produces glomalin related soil protein (GRSP). Acaulospora morroaiae, Glomus luteum, Glomus verruculosum, Glomus versiforme are the effective glomalin producing AMFs. Mixed primary forest, tropical rainforest, soil organic matter, clay soil, no tillage, quality and quantity of fertilizers, crop rotation, and water stable aggregates are also suitable to increase glomalin production. Glomalin is a glycoprotein that contains 30–40% carbon (C) which is assumed to be stable and persistent in soil. The glomalin can sequestrate more carbon in the soil due to its high carbon and aggregate stability. Greater aggregate stability leads to high organic carbon protection in terrestrial ecosystems. The lowest glomalin content (0.007 mg per gram soil) was found in Antarctic region, and the highest glomalin content (13.50 mg per gram soil) was observed in tropical rainforest. In agricultural soil, glomalin content varies between 0.30 and 0.70 mg per gram soil. The GRSP containing soil organic carbon (SOC) in deeper soil layers was 1.34 to 1.50 times higher than in surface layers. Glomalin can sequestrate 0.24 Mg C ha-1 in soil when present at 1.10±0.04 mg g-1. At elevated CO2 (700 µmol mol-1) level, easily extractable glomalin (EEG) and total glomalin (TG) were 2.76 and 5.67% SOC in the surface soil layer over ambient carbon dioxide (CO2) level. This finding indicates the effective function of GRSP C sequestration in soil under global environmental change scenarios. Glomalin can also protect labile carbon that can help regulating nutrient supply to the plants. No tillage practice causes higher AMF hyphal length, GRSP and water stable aggregate (WSA) compared to that of conventional tillage practice. The current review demonstrated that GRSP is an important tool for carbon storage in deep soils. Glomalin mediates soil aggregates, improves soil quality, increases carbon sequestration and crop production, and mitigates climate change.

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Soil Organic Carbon Stocks Mapping In Mountainous Subtropics Using A 3D Mixed Model With Upscaling Capabilities

10.31988/scitrends.49343 ◽

2019 ◽

Author(s):

Moritz Laub ◽

Sergey Blagodatsky

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Mixed Model ◽

Carbon Stocks ◽

Soil Organic Carbon Stocks

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Evaluation of organic carbon stocks in mineral and organic soils in Lithuania

Soil Use and Management ◽

10.1111/sum.12734 ◽

2021 ◽

Author(s):

Kęstutis Armolaitis ◽

Iveta Varnagirytė‐Kabašinskienė ◽

Povilas Žemaitis ◽

Vidas Stakėnas ◽

Ričardas Beniušis ◽

...

Keyword(s):

Organic Carbon ◽

Carbon Stocks ◽

Organic Soils

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Dynamics of Soil Organic Carbon and Labile Carbon Fractions in Soil Aggregates Affected by Different Tillage Managements

Sustainability ◽

10.3390/su13031541 ◽

2021 ◽

Vol 13 (3) ◽

pp. 1541

Author(s):

Xiaolin Shen ◽

Lili Wang ◽

Qichen Yang ◽

Weiming Xiu ◽

Gang Li ◽

...

Keyword(s):

Organic Carbon ◽

Soil Organic Carbon ◽

Soil Aggregates ◽

Aggregate Stability ◽

Soil Aggregate ◽

No Tillage ◽

Labile Carbon ◽

Carbon Fractions ◽

Soil Aggregate Stability ◽

Positive Effects

Our study aimed to provide a scientific basis for an appropriate tillage management of wheat-maize rotation system, which is beneficial to the sustainable development of agriculture in the fluvo-aquic soil areas in China. Four tillage treatments were investigated after maize harvest, including rotary tillage with straw returning (RT), deep ploughing with straw returning (DP), subsoiling with straw returning (SS), and no tillage with straw mulching (NT). We evaluated soil organic carbon (SOC), dissolved organic carbon (DOC), permanganate oxidizable carbon (POXC), microbial biomass carbon (MBC), and particulate organic carbon (POC) in bulk soil and soil aggregates with five particle sizes (>5 mm, 5–2 mm, 2–1 mm, 1–0.25 mm, and <0.25 mm) under different tillage managements. Results showed that compared with RT treatment, NT treatment not only increased soil aggregate stability, but also enhanced SOC, DOC, and POC contents, especially those in large size macroaggregates. DP treatment also showed positive effects on soil aggregate stability and labile carbon fractions (DOC and POXC). Consequently, we suggest that no tillage or deep ploughing, rather than rotary tillage, could be better tillage management considering carbon storage. Meanwhile, we implied that mass fractal dimension (Dm) and POXC could be effective indicators of soil quality, as affected by tillage managements.

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