scholarly journals Organic nitrogen storage in mineral soil: implications for policy and management

2015 ◽  
Vol 2 (1) ◽  
pp. 587-618 ◽  
Author(s):  
A. H. Bingham ◽  
M. F. Cotrufo
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Organic Compounds ◽  
Organic Nitrogen ◽  
Net Primary Production ◽  
Nitrogen Saturation ◽  
Mineral Soil ◽  
Chemical Complexity ◽  
Long Term Storage

Abstract. Nitrogen is one of the most important ecosystem nutrients and often its availability limits net primary production as well as stabilization of soil organic matter. The long-term storage of nitrogen-containing organic matter in soils was classically attributed to chemical complexity of plant and microbial residues that retarded microbial degradation. Recent advances have revised this framework, with the understanding that persistent soil organic matter consists largely of chemically labile, microbially processed organic compounds. Chemical bonding to minerals and physical protection in aggregates are more important to long-term (i.e., centuries to millennia) preservation of these organic compounds that contain the bulk of soil nitrogen rather than molecular complexity, with the exception of nitrogen in pyrogenic organic matter. This review examines the factors and mechanisms that influence the long-term sequestration of organic nitrogen in mineral soils. It examines the policy and management implications which stem from this newly accepted paradigm, such as critical loads considerations and nitrogen saturation and mitigation consequences. Finally, it emphasizes how essential it is for this important but underappreciated pool to be better quantified and incorporated into policy and management decisions.

Effect of temperature on soil organic matter decomposition in three forest biomes of eastern Canada

2006 ◽  
Vol 86 (Special Issue) ◽  
pp. 247-256 ◽  
Author(s):  
D. Paré ◽  
R. Boutin ◽  
G. R. Larocque ◽  
F. Raulier
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Sugar Maple ◽  
Mineral Soil ◽  
Organic Matter Decomposition ◽  
Effect Of Temperature ◽  
Organic Matter Quality ◽  
Soil Organic Matter Decomposition ◽  
Humus Layer

The sensitivity of soil organic matter decomposition to temperature change is critical tothe global carbon balance and to whether soils will respond with positive feedback to climate change. Forest cover determines litter composition, which controls to a large extent soil organic matter quality and its sensitivity to temperature. The effect of temperature on soil organic matter decomposition was studied along a latitudinal gradient encompassing sugar maple, balsam fir and black spruce forest types. Long-term laboratory soil incubations conducted at four different temperatures were used to discriminate the effect of temperature from that of organic matter quality on decomposition rates. The specific C mineralization rate of the humus layer was highest for balsam fir sites, intermediate for one sugar maple site and lowest for black spruce sites and the other sugar maple site. However, considering the total C pools of the FH layer and of the top 20 cm of mineral soil, it was estimated that coniferous sites exhibit a higher C efflux than sugar maple soils at any given temperature. Estimated C mineralization rates in the field using the temperature records for each individual site showed the same trends despite cooler temperature regimes for the coniferous sites. The Q10 respiration rates of the humus layer of all sites increased as the temperature got warmer. A significant effect of temperature on the pool size of labile C in the mineral soil was detected for some sites suggesting a potential long-term loss of C upon warming. The low estimated C evolution rates of sugar maple soils were perhaps due to the greater decomposition activity within the L layer, before the litter C enters underlying soil pools. These observations suggest that coniferous soils are not more resistant than deciduous forests to increasing their specific rates of soil heterotrophic respiration upon warming. Key words: Soil organic carbon, forest type, forest composition, warming, long-term incubation, labile carbon

scholarly journals Impacts of long-term plant residue management on soil organic matter quality, Pseudomonas community structure and disease suppressiveness

2019 ◽  
Vol 135 ◽  
pp. 396-406 ◽  
Author(s):  
Bryony E.A. Dignam ◽  
Maureen O'Callaghan ◽  
Leo M. Condron ◽  
Jos M. Raaijmakers ◽  
George A. Kowalchuk ◽  
...  
Keyword(s):  
Organic Matter ◽  
Community Structure ◽  
Soil Organic Matter ◽  
Residue Management ◽  
Plant Residue ◽  
Organic Matter Quality ◽  
Soil Organic Matter Quality

Functional soil organic matter fractions in response to long-term fertilizer management in a double-cropping paddy field of southern China

2021 ◽  
pp. 1-9
Author(s):  
Haiming Tang ◽  
Chao Li ◽  
Lihong Shi ◽  
Li Wen ◽  
Kaikai Cheng ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Paddy Field ◽  
Southern China ◽  
Rice Paddy ◽  
Chemical Fertilizer ◽  
Protection Mechanism ◽  
Rice Paddy Field ◽  
Double Cropping

Abstract Soil organic matter (SOM) and its fractions play an important role in maintaining or improving soil quality and soil fertility. Therefore, the effects of a 34-year long-term fertilizer regime on six functional SOM fractions under a double-cropping rice paddy field of southern China were studied in the current paper. The field experiment included four different fertilizer treatments: chemical fertilizer alone (MF), rice straw residue and chemical fertilizer (RF), 30% organic manure and 70% chemical fertilizer (OM) and without fertilizer input as control (CK). The results showed that coarse unprotected particulate organic matter (cPOM), biochemically, physically–biochemically and chemically protected silt-sized fractions (NH-dSilt, NH-μSilt and H-dSilt) were the main carbon (C) storage fractions under long-term fertilization conditions, accounting for 16.7–26.5, 31.1–35.6, 16.2–17.3 and 7.5–8.2% of the total soil organic carbon (SOC) content in paddy soil, respectively. Compared with control, OM treatment increased the SOC content in the cPOM, fine unprotected POM fraction, pure physically protected fraction and physico-chemically protected fractions by 58.9, 106.7, 117.6 and 28.3%, respectively. The largest proportion of SOC to total SOC in the different fractions was biochemically protected, followed by chemically and unprotected, and physically protected were the smallest. These results suggested that a physical protection mechanism plays an important role in stabilizing C of paddy soil. In summary, the results showed that higher functional SOM fractions and physical protection mechanism play an important role in SOM cycling in terms of C sequestration under the double-cropping rice paddy field.

Impact of long-term cultivation on the status of organic matter and cadmium in soil

2001 ◽  
Vol 81 (3) ◽  
pp. 349-355 ◽  
Author(s):  
D. F. E. McArthur ◽  
P M Huang ◽  
L M Kozak
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Significant Positive Correlation ◽  
Soil Organic C ◽  
Organic C ◽  
Total Soil ◽  
Total Organic C ◽  
Soil Cd ◽  
Cultivated Soils

Research has suggested a link between the bioavailability of soil Cd and total soil organic matter. However, some research suggested a negative relationship between total soil organic matter and bioavailable soil Cd while other research suggested a positive relationship. This study investigated the relationship between soil Cd and both the quantity and quality of soil organic matter as influenced by long-term cultivation. Two Orthic Chernozemic surface soil samples, one from a virgin prairie and the other from an adjacent cultivated prairie, were collected from each of 12 different sites throughout southern Saskatchewan, Canada. The samples were analyzed for total organic C, total Cd, Cd availability index (CAI), and pH. The nature of the soil organic matter was investigated with 13C Cross Polarization Magic Angle Spinning Nuclear Magnetic Resonance spectroscopy (13C CPMAS NMR). The total soil Cd, CAI, and total soil organic C of the cultivated soils were significantly lower than those of the virgin soils whereas the opposite trend was observed for the soil pH and the aromaticity of the organic C. The reduced CAI in the cultivated soils was related to the increase in both the soil pH and the aromaticity of the organic C. No relationship was found between the CAI and the soil organic C content, but a significant positive correlation was found between total organic C and total Cd in both the virgin and the cultivated soils. As well, a significant positive correlation was found between the fraction of total Cd removed from the soil after long-term cultivation and the corresponding fraction of organic C removed. Key words: Long-term cultivation, soil organic matter, 13C CPMAS NMR, cadmium

scholarly journals Priming and substrate quality interactions in soil organic matter models

2013 ◽  
Vol 10 (3) ◽  
pp. 2089-2103 ◽  
Author(s):  
T. Wutzler ◽  
M. Reichstein
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Balance Model ◽  
Levels Of Abstraction ◽  
Substrate Quality ◽  
Substrate Limitation ◽  
Energy Limitation ◽  
Bare Fallow ◽  
Different Levels

Abstract. Interactions between different qualities of soil organic matter (SOM) affecting their turnover are rarely represented in models. In this study, we propose three mathematical strategies at different levels of abstraction to represent those interactions. By implementing these strategies into the Introductory Carbon Balance Model (ICBM) and applying them to several scenarios of litter input, we show that the different levels of abstraction are applicable at different timescales. We present a simple one-parameter equation of substrate limitation that can straightforwardly be implemented into other models of SOM dynamics at decadal timescale. The study demonstrates how substrate quality interactions can explain patterns of priming effects, accelerate turnover in FACE experiments, and the slowdown of decomposition in long-term bare fallow experiments as an effect of energy limitation of microbial biomass. The mechanisms of those interactions need to be further scrutinized empirically for a more complete understanding. Overall, substrate quality interactions contribute to both understanding and quantitatively modelling SOM dynamics.

scholarly journals Effect of systematic application of mineral fertilizers and long-term aftereffect of liming on the organic matter of light-grey forest soil

2020 ◽  
Vol 21 (2) ◽  
pp. 160-168
Author(s):  
N. A. Kodochilova ◽  
T. S. Buzynina ◽  
L. D. Varlamova ◽  
E. A. Katerova
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Forest Soil ◽  
Humus Content ◽  
Total Carbon ◽  
Mineral Fertilizers ◽  
Fertilized Soil ◽  
Grey Forest Soil ◽  
Nizhny Novgorod Region

The studies on assessment of changes in the content and composition of soil organic matter under the influence of the systematic use of mineral fertilizers (NPK)1, (NPK)2, (NPK)3 against the background of the aftereffect of single liming in doses of 1.0 and 2.0 h. a. (control – variants without fertilizers and lime) were conducted in the conditions of the Nizhny Novgorod region in a long – term stationary experiment on light-grey forest soil. The research was carried out upon comple-tion of the fifth rotation of the eight-field crop rotation. The results of the study showed that for 40 years (from 1978 to 2018) the humus content in the soil (0-20 cm) decreased by 0.19-0.52 abs. % in variants as compared to the original (1.60 %); though, humus mineralization was less evident against the background of long-term use of mineral fertilizers compared to non-fertilized control. The higher humus content in the topsoil was noted in the variants with minimal (NPK)1 and increased (NPK)2 doses of fertilizer – 1.41 and 1.25 %, respectively. The humus content in non-fertilized soil and when applying high (NPK)3 doses of mineral fertilizers was almost identical – 1.08-1.09 %. The predominant group in the composition of humus were humic acids, the content of which in the experiment on average was 37.8 % of the total carbon with an evident decrease from 42.6 % in the control to 31.8% when applying increased doses of mineral fertilizers. The aftereffect of liming, carried out in 1978, was unstable and did not significantly affect the content and composition of soil organic matter.

scholarly journals Biomass of Coarse Woody Debris Following Fire and Clearcutting in Lodgepole Pine Forests

1997 ◽  
Vol 21 ◽  
pp. 33-35
Author(s):  
Dennis Knight ◽  
Daniel Tinker
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Coarse Woody Debris ◽  
Significant Contribution ◽  
Woody Debris ◽  
Mineral Soil ◽  
Primary Source ◽  
Timber Harvesting ◽  
Micro Organisms

In forest ecosystems, the decomposition of coarse woody debris, woody roots, twigs, leaves and micro-organisms is a primary source of mineral soil organic matter. Primary productivity, the accumulation of nutrients, and other important ecosystem processes are largely dependent on the mineral soil organic matter that has developed during hundreds or thousands of years. Large quantities of coarse woody debris are typically produced following natural disturbances such as fires, pest/pathogen outbreaks, and windstorms, and make a significant contribution to the formation of soil organic matter (SOM). In contrast, timber harvesting often removes much of the coarse woody debris (CWD), which could result in a decrease in the quantity and a change in the quality of mineral soil organic matter.

scholarly journals Thermal fractionation of soil organic matter produces fine-scale distributions of SOM age

2021 ◽  
Author(s):  
Shane Stoner ◽  
Carlos Sierra ◽  
Marion Schrumpf ◽  
Sebastian Dötterl ◽  
Susan Trumbore
Keyword(s):  
Thermal Stability ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Chemical Oxidation ◽  
Fine Scale ◽  
Mineral Association ◽  
Density Fractions ◽  
Chemical Complexity ◽  
Wide Range ◽  
Carbon Release

<p>Soil organic matter (SOM) is a complex collection of organic molecules of varying origin, structure, chemical activity, and mineral association. A wide array of laboratory methods exists to separate SOM based on qualitative, biological, chemical, and physical characteristics. However, all present conceptual and logistical limitations, including the requirement of a substantial amount soil material.</p><p>An newly applied alternative method of fractionation relies on a conceptual analogue between biochemical stability in soil and thermal stability, e.g. more persistent SOM will require higher temperatures (greater energy inputs) to decompose than less persistent SOM. This accounts for both chemical complexity and mineral association as main factors in determining SOM persistence.</p><p>In this method, carbon is released by heating SOM to 900°C at a constant rate. The peaks of carbon release are grouped into activation energy pools, CO<sub>2 </sub>is collected, and analyzed for <sup>13</sup>C and <sup>14</sup>C. We seek to describe in finer detail the distribution of soil radiocarbon by adding another fractionation step following a different paradigm of SOM stability, and explore mineralogical effects on SOM quality and stability using thermal analysis, radiocarbon, and gas chromatography.</p><p>Here, we analyzed bulk soil and soil fractions derived from density separation and chemical oxidation, as well as mineral horizons dominated by diverse mineralogies. Density fractions contained a wide range of radiocarbon activities and that young SOM is stabilized across multiple fractions, likely due to organomineral complexation. Initial results showed that soil minerals with limited stabilization potential released C at lower temperatures than those with diverse stabilization mechanisms. High-temperature sub-fractions contained the oldest carbon across fractions and minerals, thus supporting the assumption that thermal stability can be used as a limited analogue for stability in soil. We present a fine-scale distribution of radiocarbon in SOM and discuss the potential of this method for comparison with other fractionation techniques.</p>

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