Forms of organic C and P extracted from tropical soils as assessed by liquid-state 13C- and 31P-NMR spectroscopy

Soil Research ◽  
2000 ◽  
Vol 38 (5) ◽  
pp. 1017 ◽  
Author(s):  
A. Möller ◽  
K. Kaiser ◽  
W. Amelung ◽  
C. Niamskul ◽  
S. Udomsri ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Soil Depth ◽  
Mineral Soil ◽  
Primary Forest ◽  
Plant Residues ◽  
Organic Layer ◽  
31P Nmr Spectroscopy ◽  
Organic C ◽  
Teichoic Acids ◽  
Chemical Structures

Transformation of soil organic phosphorus (SOP) is linked with the transformation of soil organic carbon (SOC). Yet, it is uncertain to which SOC structures the cycling of SOP is related, especially in tropical environments. To clarify this issue, we determined the vertical distribution of extractable C and P chemical structures in 4 soil profiles using solution 13C- and 31P-nuclear magnetic resonance (NMR) spectroscopy after extraction with 0.1 M NaOH/0.4 M NaF (1 : 1). Soils were from a cabbage cultivation with annual burning of weeds, a Pinus reforestation, a secondary forest, and a primary forest in northern Thailand. For all profiles, signals due to O-alkyl and carbonyl C dominated the 13C-NMR spectra (up to 50 and 22% of total spectral area, respectively). The proportions of alkyl and aryl C decreased, whereas carbonyl and O-alkyl C increased with soil depth. Sharp resonances at 135 and 177 ppm appeared in spectra of subsoil horizons. They indicated mellitic acid, an end-product of the oxidation of charred plant residues. The SOP forms comprised mainly orthophosphate diesters in the organic layer of the forests, whereas in the mineral horizons orthophosphate monoesters dominated the chemical composition of extractable SOP. The relationships between SOC and SOP forms in the organic floor layers of the forests were clearly different from those in the mineral soil horizons, indicating changed SOM dynamics upon contact with soil minerals. In the forest mineral soils, significant correlations between monoester-P and O-alkyl C (R = 0.84, P < 0.001) were found. Diester-P, teichoic acids, and phosphonates were positively correlated with aromatic C and negatively with O-alkyl C. At the same time, teichoic acids and phosphonates were positively correlated with short range-ordered Al and Fe oxide phases. These findings can be explained through an increasing microbial decay of aryl C and diester-P compounds that may be less effectively stabilised at lower depths.

Organic C and nutrients in surface soils from some primary rainforests, derived grasslands and secondary rainforests on the Atherton Tableland in North East Queensland

Soil Research ◽  
1993 ◽  
Vol 31 (3) ◽  
pp. 343 ◽  
Author(s):  
J Maggs ◽  
B Hewett
Keyword(s):  
Metamorphic Rock ◽  
Forest Type ◽  
Mineral Soil ◽  
Chemical Properties ◽  
Primary Forest ◽  
Long Term Effects ◽  
Organic C ◽  
North East ◽  
Exchangeable Ca ◽  
Labile N

Some long term effects of (a) converting rainforest to grassland, and (b) rainforest regeneration on cleared land were investigated by comparing chemical properties of mineral soil (0-10 cm depth) from beneath primary rainforest, derived grassland and old secondary rainforest. Grasslands and secondary rainforest. were on land cleared at least 50 years ago. The study was undertaken on the Atherton Tableland in north east Queensland using soils formed on basalt, granite and metamorphic rocks. Organic C, kjeldahl N and labile N were 15-50% lower (P < 0.05) beneath grassland than primary rainforest for all soils, and were higher beneath secondary rainforest than grassland. Exchangeable Ca varied in a similar way in basaltic soils but did not differ between vegetation types in the other soils. Extractable Al was lower under grassland than either forest type for soils formed on granite and metamorphic rock. Total and organic P concentrations did not differ between primary forest and grassland, but were lowest under secondary rainforest for soils on metamorphic rock.

Tillage effects on the dynamics of total and corn-residue-derived soil organic matter in two southern Ontario soils

1999 ◽  
Vol 79 (3) ◽  
pp. 473-480 ◽  
Author(s):  
S. D. Wanniarachchi ◽  
R. P. Voroney ◽  
T. J. Vyn ◽  
R. P. Beyaert ◽  
A. F. MacKenzie
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Management Practices ◽  
Field Experiments ◽  
Soil Depth ◽  
Reduced Tillage ◽  
Plant Residues ◽  
Organic C ◽  
Tillage Practices ◽  
Loam Soil

Agricultural management practices affect the dynamics of soil organic matter (SOM) by influencing the amount of plant residues returned to the soil and rate of residue and SOM decomposition. Total organic C and δ13C of soil were measured in two field experiments involving corn cropping to determine the effect of tillage practices on SOM dynamics. Minimum tillage (MT) and no tillage (NT) had no significant impact on the soil C compared with conventional tillage (CT) in the 0- to 50-cm soil depth sampled at both sites. Continuous corn under MT and CT for 29 yr in a silt loam soil sequestered 61–65 g m−2 yr−1 of corn-derived C (C4-C), and it accounted for 25–26% of the total C in the 0- to 50-cm depth. In a sandy loam soil cropped to corn for 6 yr, SOM contained 10 and 8.4% C4-C under CT and NT, respectively. Reduced tillage practices altered the distribution of C4-C in soil, causing the surface (0–5 cm) soil of reduced tillage (MT and NT) plots to have higher amounts of C4-C compared to CT. Tillage practices did not affect the turnover of C3-C in soil. Key words: Soil organic matter, 13C natural abundance, tillage practices

Distribution of water-soluble organic carbon in an aspen forest soil

1996 ◽  
Vol 26 (7) ◽  
pp. 1266-1272 ◽  
Author(s):  
W.Z. Huang ◽  
J.J. Schoenau
Keyword(s):  
Forest Floor ◽  
Mineral Soil ◽  
Water Soluble ◽  
Organic Layer ◽  
Litter Fall ◽  
Organic C ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon ◽  
Prince Albert National Park ◽  
Aspen Forest

The purpose of this study was to characterize the quantity, distribution, and variance of water-soluble organic C (WSOC) in a soil under trembling aspen (Populustremuloides Michx.) in the southern boreal forest of Canada. WSOC was determined monthly from May to October 1994 in the forest floor horizons (L, F, H) and mineral soil (Ae) of an aspen stand in Prince Albert National Park, Saskatchewan. The concentration of WSOC varied considerably with profile depth, but varied little among the slope positions and aspects. The L horizon had the highest WSOC concentration (425–8690 mg•kg−1 ovendried soil), followed by the F, H, and Ae horizons. The concentration of WSOC in the Ae horizon was significantly related to the concentration in forest floor horizons above. Water-soluble organic C in the Ae horizon likely was derived from the overlying organic layer by leaching. In a laboratory incubation, the rate of WSOC release (the net result of release and uptake) during incubation decreased continuously over time, but in the field, the rate of WSOC release decreased slightly early in the growing season, but increased later in the season as new litter fall reached the forest floor. This indicates that litter fall is a major factor in the replenishment of WSOC in aspen forest stands.

Lignin, carbohydrate, and amino sugar distribution and transformation in the tropical highland soils of northern Thailand under cabbage cultivation, Pinus reforestation, secondary forest, and primary forest

Soil Research ◽  
2002 ◽  
Vol 40 (6) ◽  
pp. 977 ◽  
Author(s):  
A. Möller ◽  
K. Kaiser ◽  
W. Zech
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Secondary Forest ◽  
Mineral Soil ◽  
Amino Sugar ◽  
Primary Forest ◽  
Organic Layer ◽  
Amino Sugars ◽  
Northern Thailand ◽  
Wet Chemical

Structure and transformation processes of soil organic matter (SOM) are extremely complex, but advancing our knowledge on SOM cycling is a prerequisite for a sustainable soil management. To get a better insight to this issue, we determined the vertical distribution of lignin, carbohydrates, and amino sugars in bulk soils and NaOH-extracts using wet chemical techniques. These results were compared with those obtained by solution 13C nuclear magnetic resonance (NMR) spectroscopy after alkaline extraction. Soil samples were taken under a primary forest, a secondary forest, a 20-year-old Pinus kesiya (Royle ex Gordon) reforestation established following 15 years of cultivation, and a cabbage cultivation site in northern Thailand. Significantly lower contents of organic C and N at the cabbage cultivation and reforestation sites indicated that the replacement of forests by arable land at the reforestation and cabbage cultivation sites about 30 years ago resulted in enhanced breakdown of SOM. This means that after 20 years of Pinus growth, reforestation did not lead to a significant build-up of organic matter in the mineral soil. With increasing soil depth the sites showed comparable decreases in soil organic matter, exhibiting a typical pattern of decomposition expressed by a higher degree of side chain oxidation, increasing carboxyl functionality, and a decrease of lignin-derived phenols and aromatic compounds. Microbial contribution to SOM was determined using the carbohydrate and amino sugar biomarker approach. The amino sugars were predominantly of fungal origin in the organic layer. In the mineral soil, bacterial amino sugars dominated and the relative contribution of amino sugars to SOM increased with depth. Comparison of results from wet chemical analyses and of liquid-state 13C NMR signatures requires that alkaline-extractable organic matter is representative for bulk soil organic matter. This seemed to apply to lignin-derived phenols and amino sugars but not to neutral sugars and uronic acids. Significant correlations were found for lignin-derived phenols with phenolic C (R = 0.74, P &lt; 0.01) for the bulk forest site samples and amino sugars with O-alkyl C (R = 0.93, P &lt; 0.001) for the mineral soil horizons, whereas the carbohydrate contents did not show any clear correlation. Therefore, we concluded that most of the phenolic C signal intensity might be attributed to lignin, and the enrichment of O-alkyl C with depth may be a result of bacterial resynthesis with a significant contribution of amino sugars.

scholarly journals Estimating fine root longevity in a temperate Norway spruce forest using three independent methods

2009 ◽  
Vol 36 (1) ◽  
pp. 11 ◽  
Author(s):  
Dirk Gaul ◽  
Dietrich Hertel ◽  
Christoph Leuschner
Keyword(s):  
Norway Spruce ◽  
Fine Root ◽  
Soil Depth ◽  
Mineral Soil ◽  
Mean Value ◽  
Root Diameter ◽  
Organic Layer ◽  
Mean Values ◽  
Root Longevity ◽  
Fine Root Longevity

The importance of root systems for C cycling depends crucially on fine root longevity. We investigated mean values for fine root longevity with root diameter, root C/N ratio and soil depth using radiocarbon (14C) analyses in a temperate Norway spruce [Picea abies (L.) Karst.] forest. In addition, we applied sequential soil coring and minirhizotron observations to estimate fine root longevity in the organic layer of the same stand. The mean radiocarbon age of C in fine roots increased with depth from 5 years in the organic layer to 13 years in 40–60 cm mineral soil depth. Similarly, the C/N ratios of fine root samples were lowest in the organic layer with a mean value of 24 and increased with soil depth. Roots >0.5 mm in diameter tended to live longer than those being <0.5 mm in diameter. By far the strongest variability in fine root longevity estimates was due to the chosen method of investigation, with radiocarbon analyses yielding much higher estimates (5.4 years) than sequential soil coring (0.9 years) and minirhizotron observations (0.7 years). We conclude that sequential soil coring and minirhizotron observations are likely to underestimate mean fine root longevity, and radiocarbon analyses may lead to an overestimation of mean root longevity.

scholarly journals The Vertical Distribution Pattern of Microbial- and Plant-Derived Carbon in the Rhizosphere in Alpine Coniferous Forests

2021 ◽  
Author(s):  
Wentong Gao ◽  
Qitong Wang ◽  
Xiaoming Zhu ◽  
Zhanfeng Liu ◽  
Na Li ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Distribution Pattern ◽  
Soil Depth ◽  
Dominant Role ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Organic C ◽  
Vertical Distribution Pattern ◽  
Picea Asperata ◽  
The Vertical Distribution

Abstract Background and aimsWhile the quantitative assessment of plant- and microbial-derived carbon (C) in the soil organic C (SOC) chemical composition in soil profiles has been initially explored, the vertical distribution pattern of these two C sources and their dominant role in SOC formation based on the insights related to the rhizosphere are still lacking.MethodsWe quantified the divergent accumulation of microbial-derived C (i.e., microbial residues), plant-derived C (i.e., lipids and lignin phenols) and SOC in the rhizosphere at various depths (0-10 cm, 10-20 cm and 20-30 cm) in the upper mineral soil and analyzed its control factors in an alpine coniferous forest (Picea asperata. Mast). We further revealed the relative contribution of plant- or microbial-derived C to rhizosphere SOC in the soil profile.ResultsThe contents of microbial- and plant-derived C and SOC in the rhizosphere decreased with soil depth and were mainly regulated by root and microbial biomass. Moreover, the contribution of microbial-derived C dominated by fungal residues to rhizosphere SOC at each soil depth (more than 62%) was much higher than that of plant-derived C (less than 6%), implying that the soil microbial C pump was intensely stimulated in the rhizosphere.ConclusionsThese results indicated that microbial-derived C was the main contributor of rhizosphere SOC at various depths in the upper mineral soil. Our findings provide direct experimental evidence for assessing the dominant contribution of microbial- or plant-derived C to SOC in the soil profile from the perspective of the rhizosphere.

scholarly journals Laboratory measurements of nitric oxide release from forest soil with a thick organic layer under different understory types

2010 ◽  
Vol 7 (5) ◽  
pp. 1425-1441 ◽  
Author(s):  
A. Bargsten ◽  
E. Falge ◽  
K. Pritsch ◽  
B. Huwe ◽  
F. X. Meixner
Keyword(s):  
Nitric Oxide ◽  
Water Content ◽  
Vegetation Type ◽  
Mineral Soil ◽  
Soil Conditions ◽  
Organic Layer ◽  
No Emission ◽  
Organic C ◽  
Physical And Chemical ◽  
No Fluxes

Abstract. Nitric oxide (NO) plays an important role in the photochemistry of the troposphere. NO from soil contributes up to 40% to the global budget of atmospheric NO. Soil NO emissions are primarily caused by biological activity (nitrification and denitrification), that occurs in the uppermost centimeter of the soil, a soil region often characterized by high contents of organic material. Most studies of NO emission potentials to date have investigated mineral soil layers. In our study we sampled soil organic matter under different understories (moss, grass, spruce and blueberries) in a humid mountainous Norway spruce forest plantation in the Fichtelgebirge (Germany). We performed laboratory incubation and flushing experiments using a customized chamber technique to determine the response of net potential NO flux to physical and chemical soil conditions (water content and temperature, bulk density, particle density, pH, C/N ratio, organic C, soil ammonium, soil nitrate). Net potential NO fluxes (in terms of mass of N) from soil samples taken under different understories ranged from 1.7–9.8 ng m−2 s−1 (soil sampled under grass and moss cover), 55.4–59.3 ng m−2 s−1 (soil sampled under spruce cover), and 43.7–114.6 ng m−2 s−1 (soil sampled under blueberry cover) at optimum water content and a soil temperature of 10 °C. The water content for optimum net potential NO flux ranged between 0.76 and 0.8 gravimetric soil moisture for moss covered soils, between 1.0 and 1.1 for grass covered soils, 1.1 and 1.2 for spruce covered soils, and 1.3 and 1.9 for blueberry covered soils. Effects of soil physical and chemical characteristics on net potential NO flux were statistically significant (0.01 probability level) only for NH4+. Therefore, as an alternative explanation for the differences in soil biogenic NO emission we consider more biological factors like understory vegetation type, amount of roots, and degree of mycorrhization; they have the potential to explain the observed differences of net potential NO fluxes.

scholarly journals Laboratory measurements of nitric oxide release from forest soil with a thick organic layer under different understory types

2010 ◽  
Vol 7 (1) ◽  
pp. 203-250 ◽  
Author(s):  
A. Bargsten ◽  
E. Falge ◽  
B. Huwe ◽  
F. X. Meixner
Keyword(s):  
Nitric Oxide ◽  
Water Content ◽  
Mineral Soil ◽  
Soil Conditions ◽  
Organic Layer ◽  
No Emission ◽  
Organic C ◽  
Physical And Chemical ◽  
No Fluxes ◽  
No Emissions

Abstract. Nitric oxide (NO) plays an important role in the photochemistry of the troposphere. NO from soil contributes up to 40% to the global budget of atmospheric NO. Soil NO emissions are primarily caused by biological activity (nitrification and denitrification), that occurs in the uppermost centimetres of the soil, a soil region often characterized by high contents of organic material. Most studies of NO emission potentials to date have investigated mineral soil layers. In our study we sampled soil organic matter under different understories (moss, grass, spruce and blueberries) in a humid mountainous Norway spruce forest plantation in the Fichtelgebirge (Germany). We performed laboratory incubation and fumigation experiments using a customized chamber technique to determine the response of net potential NO flux to physical and chemical soil conditions (water content and temperature, bulk density, particle density, pH, C/N ratio, organic C, soil ammonium, soil nitrate). Net potential NO fluxes (in terms of mass of N) from soils of different understories ranged from 1.7–9.8 ng m−2 s−1 (grass and moss), 55.4–59.3 ng m−2 s−1 (spruce), and 43.7–114.6 ng m−2 s−1 (blueberry) at optimum water content and a soil temperature of 10°C. The water content for optimum net potential NO flux ranged between 0.76 and 0.8 gravimetric soil moisture for moss, between 1.0 and 1.1 for grass, 1.1 and 1.2 for spruce, and 1.3 and 1.9 for blueberries. Effects of soil physical and chemical characteristics on net potential NO flux were statistically significant (0.01 probability level) only for NH4+. Therefore, the effects of biogenic factors like understory type, amount of roots, and degree of mycorrhization on soil biogenic NO emission are discussed; they have the potential to explain the observed different of net potential NO fluxes. Quantification of NO emissions from the upmost soil layer is therefore an important step to quantify soil NO emissions in ecosystems with substantial organic soil horizons.

scholarly journals Soil depth matters: Shift in composition and inter-kingdom co-occurrence patterns of microorganisms in forest soils

2021 ◽  
Author(s):  
Sunil Mundra ◽  
O Janne Kjønaas ◽  
Luis N Morgado ◽  
Anders Kristian Krabberød ◽  
Yngvild Ransedokken ◽  
...  
Keyword(s):  
Soil Depth ◽  
Mineral Soil ◽  
Soil Microbial Communities ◽  
Biotic Interactions ◽  
Sharp Decrease ◽  
Organic Layer ◽  
Mineral Layer ◽  
Network Analyses ◽  
Microbial Groups ◽  
Occurrence Patterns

Abstract Soil depth represents a strong physiochemical gradient that greatly affects soil-dwelling microorganisms. Fungal communities are typically structured by soil depth, but how other microorganisms are structured is less known. Here, we tested whether depth-dependent variation in soil chemistry affects the distribution and co-occurrence patterns of soil microbial communities. This was investigated by DNA metabarcoding in conjunction with network analyses of bacteria, fungi, as well as other micro-eukaryotes, sampled in four different soil depths in Norwegian birch forests. Strong compositional turnover in microbial assemblages with soil depth was detected for all organismal groups. Significantly greater microbial diversity and fungal biomass appeared in the nutrient-rich organic layer, with sharp decrease towards the less nutrient-rich mineral zones. The proportions of copiotrophic bacteria, Arthropoda and Apicomplexa were markedly higher in the organic layer, while patterns were opposite for oligotrophic bacteria, Cercozoa, Ascomycota and ectomycorrhizal fungi. Network analyses indicated more intensive inter-kingdom co-occurrence patterns in the upper mineral layer (0-5 cm) compared to the above organic and the lower mineral soil, signifying substantial influence of soil depth on biotic interactions. This study supports the view that different microbial groups are adapted to different forest soil strata, with varying level of interactions along the depth gradient.

Quantitative Determination of Krill Oil Composition by ATR-FTIR, NIR, and 31P NMR Spectroscopy

2020 ◽  
Author(s):  
Ashraf Ismail ◽  
Sanaz Molaye Moghaddam ◽  
Jean-Pierre MetabanzoulouSarya Aziz ◽  
Jacqueline Sedman ◽  
Mazen Bahadi
Keyword(s):  
Nmr Spectroscopy ◽  
Quantitative Determination ◽  
31P Nmr ◽  
31P Nmr Spectroscopy ◽  
Krill Oil ◽  
Oil Composition
Sign in / Sign up

Export Citation Format

Share Document