Differential thermogravimetry and differential scanning calorimetry of soil organic matter in mineral horizons: Effect of wildfires and land use

&#8216;Machair&#8217; describes a landscape form that is present along the Atlantic seaboard of Scotland and Ireland, and that is characterized by a gently sloping coastal plain developed from aeolian carbonate and quartzose sand. We characterized three grassland soil profiles along a coastal transect on Harris (Outer Hebrides, Scotland) by standard methods (colour, texture, pH, wet-chemical extractions), infrared spectroscopy, X-ray diffractometry, X-ray fluorescence spectrometry and differential scanning calorimetry. Our aim was to understand the impacts of humankind, matter input, weathering and accumulation of soil organic matter (SOM) on chemical processes and soil properties. One of the profiles differed distinctly from the other two, in particular regarding depth, texture, carbonate and SOM contents, and properties of SOM (relative content of rather labile permanganate-oxidizable SOM, transformation state), presumably caused by earlier land use as arable land. We classified the soil with the least depth as Hypereutric Leptosol, and the others as Cambic and Calcaric Phaeozem. Thermally stable SOM was present in all samples, likely pointing to pyrogenic SOM, i.e. black carbon. The mineralogical composition differed among the profiles and reflected the intermediate character of the local rocks. In all topsoil horizons, we identified Mg-hydroxy-interlayered minerals (HIMs), which are rather rare, given the commonly low abundance of Mg ions in the soil solution relative to Ca, or Al in acidic soil. The share of Mg-HIMs of the total minerals in the clay fraction ranged from 25% in a subsoil to 71% in a topsoil horizon. We suggest that sea spray is the source of subsequently intercalated Mg. This composition of the clay fraction, which is possibly typical of soil on certain machair sites, and is the result of a pedogenic process, surely affects soil properties and processes such as cation exchange capacity and SOM storage and thus element cycles.

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Accumulation patterns of soil organic matter in forests as a legacy of historical charcoal burning

10.5194/egusphere-egu21-5161 ◽

2021 ◽

Author(s):

Anna Schneider ◽

Alexander Bonhage ◽

Florian Hirsch ◽

Alexandra Raab ◽

Thomas Raab

Keyword(s):

Land Use ◽

Organic Matter ◽

Soil Organic Matter ◽

Large Scale ◽

Soil Surface ◽

Landscape Scale ◽

Legacy Effects ◽

Charcoal Production ◽

Study Region ◽

Land Use Legacies

Human land use and occupation often lead to a high heterogeneity of soil stratigraphy and properties in landscapes within small, clearly delimited areas. Legacy effects of past land use also are also abundant in recent forest areas. Although such land use legacies can occur on considerable fractions of the soil surface, they are hardly considered in soil mapping and inventories. The heterogenous spatial distribution of land use legacy soils challenges the quantification of their impacts on the landscape scale. Relict charcoal hearths (RCH) are a widespread example for the long-lasting effect of historical land use on soil landscapes in forests of many European countries and also northeastern USA. Soils on RCH clearly differ from surrounding forest soils in their stratigraphy and properties, and are most prominently characterized by a technogenic substrate layer with high contents of charcoal. The properties of RCH soils have recently been studied for several regions, but their relevance on the landscape scale has hardly been quantified.We analyse and discuss the distribution and ecological relevance of land use legacy soils across scales for RCH in the state of Brandenburg, Germany, with a focus on soil organic matter (SOM) stocks. Our analysis is based on a large-scale mapping of RCH from digital elevation models (DEM), combined with modelled SOM stocks in RCH soils.&#160;The distribution of RCH soils in the study region shows heterogeneity at different scales. The large-scale variation is related to the concentration of charcoal production to specific forest areas and the small-scale accumulation pattern is related to the irregular distribution of single RCH within the charcoal production fields. Considerable fractions of the surface area are covered by RCH soils in the major charcoal production areas within the study region. The results also show that RCH can significantly contribute to the soil organic matter stocks of forests, even for areas where they cover only a small fraction of the soil surface. The study highlights that considering land use legacy effects can be relevant for the results of soil mapping and inventories; and that prospecting and mapping land use legacies from DEM can contribute to improving such approaches.

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Land Use and Soil Management Effects on Soil Organic Matter Dynamics on Alfisols In Western Nigeria

Soil Processes and the Carbon Cycle ◽

10.1201/9780203739273-9 ◽

2018 ◽

pp. 109-126 ◽

Cited By ~ 5

Author(s):

R. Lal

Keyword(s):

Land Use ◽

Organic Matter ◽

Soil Organic Matter ◽

Soil Management ◽

Soil Organic Matter Dynamics ◽

Organic Matter Dynamics ◽

Management Effects

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Effects of changing land use in the Netherlands on net carbon fixation.

Netherlands Journal of Agricultural Science ◽

10.18174/njas.v39i4.16534 ◽

1991 ◽

Vol 39 (4) ◽

pp. 237-246 ◽

Cited By ~ 3

Author(s):

J. Wolf ◽

L.H.J.M. Janssen

Keyword(s):

Land Use ◽

Organic Matter ◽

Soil Organic Matter ◽

The Netherlands ◽

Input Data ◽

Carbon Fixation ◽

Arable Land ◽

Rate Of Change ◽

Pool Size ◽

Average Amount

The changed crop rotation on arable land, the decreasing grassland area and the increase in forest area in the Netherlands resulted in a decrease in C pool size. For the calculation of this C pool a method requiring only three input data (average amount of crop or tree residue rate, soil organic matter decomposition and the humification coefficient) has been applied. However the method can only be applied to situations in equilibrium where all three input data are equal. For a changing land use a new state of equilibrium and rate of change in C pool size can be calculated. (Abstract retrieved from CAB Abstracts by CABI’s permission)

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Land use impacts on physical-based soil organic matter fractions on three hillside Ferrasols in Mexico

Chilean journal of agricultural research ◽

10.4067/s0718-58392011000200014 ◽

2011 ◽

Vol 71 (2) ◽

pp. 283-292 ◽

Cited By ~ 2

Author(s):

Francisco Matus ◽

Claudia Hidalgo ◽

Carlos Monreal ◽

Isabel Estrada ◽

Mariela Fuentes ◽

...

Keyword(s):

Land Use ◽

Organic Matter ◽

Soil Organic Matter ◽

Land Use Impacts ◽

Soil Organic Matter Fractions ◽

Organic Matter Fractions

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Land Use Changes Affecting Soil Organic Matter Accumulation in Topsoil and Subsoil in Northeast Thailand

Applied and Environmental Soil Science ◽

10.1155/2020/8241739 ◽

2020 ◽

Vol 2020 ◽

pp. 1-15

Author(s):

Benjapon Kunlanit ◽

Laksanara Khwanchum ◽

Patma Vityakon

Keyword(s):

Land Use ◽

Organic Matter ◽

Soil Organic Matter ◽

Agricultural Land ◽

Soil Depth ◽

General Pattern ◽

Clay Fraction ◽

High Rate ◽

Soil Profiles ◽

Land Uses

The objectives of this study were to investigate effects of land use on accumulation of soil organic matter (SOM) in the soil profile (0–100 cm) and to determine pattern of SOM stock distribution in soil profiles. Soil samples were collected from five soil depths at 20 cm intervals from 0 to 100 cm under four adjacent land uses including forest, cassava, sugarcane, and paddy lands located in six districts of Maha Sarakham province in the Northeast of Thailand. When considering SOM stock among different land uses in all locations, forest soils had significantly higher total SOM stocks in 0–100 cm (193 Mg·C·ha−1) than those in cassava, sugarcane, and paddy soils in all locations. Leaf litter and remaining rice stover on soil surfaces resulted in a higher amount of SOM stocks in topsoil (0–20 cm) than subsoil (20–100 cm) in some forest and paddy land uses. General pattern of SOM stock distribution in soil profiles was such that the SOM stock declined with soil depth. Although SOM stocks decreased with depth, the subsoil stock contributes to longer term storage of C than topsoils as they are more stabilized through adsorption onto clay fraction in finer textured subsoil than those of the topsoils. Agricultural practices, notably applications of organic materials, such as cattle manure, could increase subsoil SOM stock as found in some agricultural land uses (cassava and sugarcane) in some location in our study. Upland agricultural land uses, notably cassava, caused high rate of soil degradation. To restore soil fertility of these agricultural lands, appropriate agronomic practices including application of organic soil amendments, return of crop residues, and reduction of soil disturbance to increase and maintain SOM stock, should be practiced.

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