Organic matter stabilization in a Xanthic Ferralsol of the central Amazon as affected by single trees: chemical characterization of density, aggregate, and particle size fractions

Lehmann, Johannes; Cravo, M. da S.; Zech, Wolfgang

doi:10.1016/s0016-7061(00)00070-7

Cited by 63 publications

(36 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This may be explained by the low levels of aggregation in the coarse-silty mixed mesic Typic Haploxerolls studied by Knoth (2004); whereas, the Kenyan Ultisols studied here are more strongly aggregated. Lehmann et al (2001) found that for a highly aggregated Xanthic Ferralsol in the central Amazon, the amount of organic C had no effect on aggregation.…”

Section: Pre-existing Soc and The Stabilisation Of Added Organic Carbonmentioning

confidence: 95%

Stability and stabilisation of biochar and green manure in soil with different organic carbon contents

2010

Self Cite

View full text Add to dashboard Cite

Abstract. Due to its recalcitrance against microbial degradation, biochar is very stable in soil compared to other organic matter additions, making its application to soils a suitable approach for the build-up of soil organic carbon (SOC). The net effects of such biochar addition also depend on its interactions with existing organic matter in soils. A study was established to investigate how the status of pre-existing soil organic matter influences biochar stabilisation in soil in comparison to labile organic additions. Carbon loss was greater in the C-rich sites (C content 58.0 g C/kg) than C-poor soils (C content 21.0-24.0 g C/kg), regardless of the quality of the applied organic resource. Biochar-applied, C-rich soil showed greater C losses, by >0.5 kg/m 2 .year, than biochar-applied C-poor soil, whereas the difference was only 0.1 kg/m 2 .year with Tithonia diversifolia green manure. Biochar application reduced the rate of CO 2 -C loss by 27%, and T. diversifolia increased CO 2 -C losses by 22% in the C-poor soils. With biochar application, a greater proportion of C (6.8 times) was found in the intraaggregate fraction per unit C respired than with green manure, indicating a more efficient stabilisation in addition to the chemical recalcitrance of biochar. In SOC-poor soils, biochar application enriched aromatic-C, carboxyl-C, and traces of ketones and esters mainly in unprotected organic matter and within aggregates, as determined by Fourier-transform infrared spectroscopy. In contrast, additions of T. diversifolia biomass enriched conjugated carbonyl-C such as ketones and quinones, as well as CH deformations of aliphatic-C mainly in the intra-aggregate fraction. The data indicate that not only the stability but also the stabilisation of biochar exceeds that of a labile organic matter addition such as green manure.

show abstract

Section: Pre-existing Soc and The Stabilisation Of Added Organic Carbonmentioning

confidence: 95%

Stability and stabilisation of biochar and green manure in soil with different organic carbon contents

2010

Self Cite

View full text Add to dashboard Cite

show abstract

“…Aggregate size-distribution was expressed as the mean weight diameter (MWD) after dry and wet sieving. Stability of the aggregates was evaluated using a ratio of wet-to-dry MWD (MWDw/MWDd) [62,63]. For SQ evaluation with SMAF, the proportion of water-stable aggregates bigger than 0.25 mm (WSA) was obtained after wet sieving.…”

Section: Physical Propertiesmentioning

confidence: 99%

Tillage Effects on Soil Quality after Three Years of Irrigation in Northern Spain

et al. 2017

View full text Add to dashboard Cite

Abstract:Irrigation is being initiated on large areas of traditionally rainfed land to meet increasing global demand for food, feed, fiber and fuel. However, the consequences of this transition on soil quality (SQ) have scarcely been studied. Therefore, after previously identifying the most tillage-sensitive SQ indicators under long-term rainfed conditions, conversion of a research site on a Haplic Calcisol in Navarre, in northeast Spain provided an ideal location to reevaluate those SQ indicators after three years of irrigated management. The Soil Management Assessment Framework (SMAF) was used to test our hypothesis that adopting irrigation could change the sensitivity and importance of non-irrigated SQ indicators. Several soil physical, chemical, and biological indicators along with crop yields were used to evaluate SQ three years after initiating irrigation on a long-term conventional tillage (CT), minimum tillage (MT) and no-tillage (NT) study where either barley (Hordeum vulgare L.) or wheat (Triticum aestivum L.) was being grown. The results confirmed our hypothesis that irrigation would change the relative importance of various SQ indicators and suggested that some SMAF algorithms, such as those used to assess bulk density, needed to be recalibrated for these Mediterranean soils.

show abstract

“…Cayet and Lichtfouse, 2001;Lehmann et al, 2001;Magid et al, 2010;Nelson et al, 1994;Römkens et al, 1999;Shang and Tiessen, 2000) relies on the same ideas as the ASF but a density separation is performed together with the size separation to ensure that only true aggregates are separated by size. Provided that the true aggregate fraction is properly isolated, the ASDF procedure, like the PSDF, is very useful to investigate the role of soil structure in SOM-dynamics.…”

Section: Moni Et Al: Density Fractions Versus Size Separatesmentioning

confidence: 99%

Density fractions versus size separates: does physical fractionation isolate functional soil compartments?

et al. 2012

View full text Add to dashboard Cite

Abstract. Physical fractionation is a widely used methodology to study soil organic matter (SOM) dynamics, but concerns have been raised that the available fractionation methods do not well describe functional SOM pools. In this study we explore whether physical fractionation techniques isolate soil compartments in a meaningful and functionally relevant way for the investigation of litter-derived nitrogen dynamics at the decadal timescale. We do so by performing aggregate density fractionation (ADF) and particle size-density fractionation (PSDF) on mineral soil samples from two European beech forests a decade after application of 15 N labelled litter.Both density and size-based fractionation methods suggested that litter-derived nitrogen became increasingly associated with the mineral phase as decomposition progressed, within aggregates and onto mineral surfaces. However, scientists investigating specific aspects of litter-derived nitrogen dynamics are pointed towards ADF when adsorption and aggregation processes are of interest, whereas PSDF is the superior tool to research the fate of particulate organic matter (POM).Some methodological caveats were observed mainly for the PSDF procedure, the most important one being that fine fractions isolated after sonication can not be linked to any defined decomposition pathway or protective mechanism. This also implies that historical assumptions about the "adsorbed" state of carbon associated with fine fractions need to be reevaluated. Finally, this work demonstrates that establishing a comprehensive picture of whole soil OM dynamics requires a combination of both methodologies and we offer a suggestion for an efficient combination of the density and size-based approaches.

show abstract

Organic matter stabilization in a Xanthic Ferralsol of the central Amazon as affected by single trees: chemical characterization of density, aggregate, and particle size fractions

Cited by 63 publications

References 32 publications

Stability and stabilisation of biochar and green manure in soil with different organic carbon contents

Stability and stabilisation of biochar and green manure in soil with different organic carbon contents

Tillage Effects on Soil Quality after Three Years of Irrigation in Northern Spain

Density fractions versus size separates: does physical fractionation isolate functional soil compartments?

Contact Info

Product

Resources

About