Rate of decomposition of organic matter in soil as influenced by repeated air drying-rewetting and repeated additions of organic material

1974 ◽  
Vol 6 (5) ◽  
pp. 287-292 ◽  
Author(s):  
L.H. Sørensen
Keyword(s):  
Organic Matter ◽  
Organic Material ◽  
Air Drying ◽  
Decomposition Of Organic Matter

Controlling Erosion

1999 ◽  
Author(s):  
Robert F. Keefer
Keyword(s):  
Organic Matter ◽  
Organic Material ◽  
Soil Structure ◽  
Soil Microorganisms ◽  
Soil Aggregation ◽  
Water Infiltration ◽  
Root Penetration ◽  
Animal Remains ◽  
Decomposition Of Organic Matter ◽  
Structure Improvement

Erosion can be controlled by four main means, that is, improving soil structure, covering soil with plants, covering soil with mulch, and using special structures. Soil structure is related to the soil tilth, or physical condition of a soil, with respect to ease of tillage or workability as shown by the fitness of a soil as a seedbed and the ease of root penetration. Other terms relating to soil structure improvement are soil aggregation and the formation of aggregates. Aggregates form when a cementing substance is present in a soil. The most important cementing substances in soil are soil polysaccharides and soil polyuronides produced as by-products from microorganisms during decomposition of organic matter. Other less important cementing substances in soil include clays, Ca, and Fe. Formation of aggregates results in improved water infiltration with reduction in erosion. Decomposition of organic matter in soils can be shown as an equation: . . . Plant and animal remains + O2 + soil microorganisms → CO2 + H2O + elements + humus + synthates + energy . . . The decomposition process has the following features: . . . 1. Oxygen is required; thus soil aeration is important. Anytime a soil is stirred or mixed by cultivation, spading, plowing, some organic matter decomposition occurs. 2. Readily available decomposable organic material is required for the microbes to work on. Green organic material, such as grass clippings, is an excellent substrate. 3. Many different types of soil microorganisms are involved in this process. Decomposition is more rapid in soils at pH 7 (neutral). 4. A product of organic decomposition is humus. Humus has many desirable features that improve a soil for plant growth. 5. Plant or animal remains are not effective in soil aggregation until they begin to decompose. 6. The more rapid the decomposition, the greater effect of soil aggregation. . . . Microbial synthates consist of polymers called “polysaccharides” and “polyuronides.” A polymer is a long-chain compound made up of single monomer units hooked together acting as a unit. The term “poly” means “many” and “saccharide” means “sugar.”

scholarly journals The riverine bioreactor: An integrative perspective on biological decomposition of organic matter across riverine habitats

2021 ◽  
Vol 772 ◽  
pp. 145494
Author(s):  
Ignacio Peralta-Maraver ◽  
Rachel Stubbington ◽  
Shai Arnon ◽  
Pavel Kratina ◽  
Stefan Krause ◽  
...  
Keyword(s):  
Organic Matter ◽  
Decomposition Of Organic Matter ◽  
Riverine Habitats ◽  
Biological Decomposition

scholarly journals Syngenetic rapid growth of ellipsoidal silica concretions with bitumen cores

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hidekazu Yoshida ◽  
Ryusei Kuma ◽  
Hitoshi Hasegawa ◽  
Nagayoshi Katsuta ◽  
Sin-iti Sirono ◽  
...  
Keyword(s):  
Organic Matter ◽  
Early Diagenesis ◽  
Ph Change ◽  
Carbon Preference Index ◽  
Diffusion Growth ◽  
Silica Precipitation ◽  
Precipitated Silica ◽  
Preference Index ◽  
Decomposition Of Organic Matter ◽  
Growth Diagram

AbstractIsolated silica concretions in calcareous sediments have unique shapes and distinct sharp boundaries and are considered to form by diagenesis of biogenic siliceous grains. However, the details and rates of syngenetic formation of these spherical concretions are still not fully clear. Here we present a model for concretion growth by diffusion, with chemical buffering involving decomposition of organic matter leading to a pH change in the pore-water and preservation of residual bitumen cores in the concretions. The model is compatible with some pervasive silica precipitation. Based on the observed elemental distributions, C, N, S, bulk carbon isotope and carbon preference index (CPI) measurements of the silica-enriched concretions, bitumen cores and surrounding calcareous rocks, the rate of diffusive concretion growth during early diagenesis is shown using a diffusion-growth diagram. This approach reveals that ellipsoidal SiO2 concretions with a diameter of a few cm formed rapidly and the precipitated silica preserved the bitumen cores. Our work provides a generalized chemical buffering model involving organic matter that can explain the rapid syngenetic growth of other types of silica accumulation in calcareous sediments.

INFLUENCE OF SOIL ACIDITY UPON THE DECOMPOSITION OF ORGANIC MATTER IN SOILS

Soil Science ◽  
1934 ◽  
Vol 37 (1) ◽  
pp. 1-14 ◽  
Author(s):  
J. W. WHITE ◽  
F. J. HOLBEN ◽  
C. D. JEFFRIES
Keyword(s):  
Organic Matter ◽  
Soil Acidity ◽  
Decomposition Of Organic Matter

The impact of porosity on organic matter cycling in a two-dimensional porous medium 

2021 ◽  
Author(s):  
Hanbang Zou ◽  
Pelle Ohlsson ◽  
Edith Hammer
Keyword(s):  
Porous Medium ◽  
Organic Matter ◽  
Carbon Sequestration ◽  
Soil Carbon ◽  
Pore Network ◽  
Pore Scale ◽  
Decomposition Of Organic Matter ◽  
Organic Matter Cycling ◽  
The Impact

<p>Carbon sequestration has been a popular research topic in recent years as the rapid elevation of carbon emission has significantly impacted our climate. Apart from carbon capture and storage in e.g. oil reservoirs, soil carbon sequestration offers a long term and safe solution for the environment and human beings. The net soil carbon budget is determined by the balance between terrestrial ecosystem sink and sources of respiration to atmospheric carbon dioxide. Carbon can be long term stored as organic matters in the soil whereas it can be released from the decomposition of organic matter. The complex pore networks in the soil are believed to be able to "protect" microbial-derived organic matter from decomposition. Therefore, it is important to understand how soil structure impacts organic matter cycling at the pore scale. However, there are limited experimental studies on understanding the mechanism of physical stabilization of organic matter. Hence, my project plan is to create a heterogeneous microfluidic porous microenvironment to mimic the complex soil pore network which allows us to investigate the ability of organisms to access spaces starting from an initial ecophysiological precondition to changes of spatial accessibility mediated by interactions with the microbial community.</p><p>Microfluidics is a powerful tool that enables studies of fundamental physics, rapid measurements and real-time visualisation in a complex spatial microstructure that can be designed and controlled. Many complex processes can now be visualized enabled by the development of microfluidics and photolithography, such as microbial dynamics in pore-scale soil systems and pore network modification mimicking different soil environments – earlier considered impossible to achieve experimentally. The microfluidic channel used in this project contains a random distribution of cylindrical pillars of different sizes so as to mimic the variations found in real soil. The randomness in the design creates various spatial availability for microbes (preferential flow paths with dead-end or continuous flow) as an invasion of liquids proceeds into the pore with the lowest capillary entry pressure. In order to study the impact of different porosity in isolation of varying heterogeneity of the porous medium, different pore size chips that use the same randomly generated pore network is created. Those chips have the same location of the pillars, but the relative size of each pillar is scaled. The experiments will be carried out using sterile cultures of fluorescent bacteria, fungi and protists, synthetic communities of combinations of these, or a whole soil community inoculum. We will quantify the consumption of organic matter from the different areas via fluorescent substrates, and the bio-/necromass produced. We hypothesise that lower porosity will reduce the net decomposition of organic matter as the narrower pore throat limits the access, and that net decomposition rate at the main preferential path will be higher than inside branches</p>

scholarly journals EVALUATION OF THREE SURFACE FRICTION TECHNIQUES FOR THE REMOVAL OF ORGANIC MATTER

2015 ◽  
Vol 24 (4) ◽  
pp. 1061-1070 ◽  
Author(s):  
Marcelo Alessandro Rigotti ◽  
Adriano Menis Ferreira ◽  
Mara Corrêa Lelles Nogueira ◽  
Margarete Teresa Gottardo de Almeida ◽  
Odanir Garcia Guerra ◽  
...  
Keyword(s):  
Organic Matter ◽  
Adenosine Triphosphate ◽  
Organic Material ◽  
Surface Friction ◽  
Disinfection Process ◽  
Significant Difference ◽  
Before And After ◽  
Quantitative Descriptive ◽  
The One ◽  
Cleaning And Disinfection

ABSTRACT The objective of this study was to assess the effectiveness of three surface friction techniques for the removal of organic material. A quantitative, descriptive and exploratory study was developed to evaluate the presence or not of organic material before and after the cleaning and disinfection process of surfaces of bedside tables of patients hospitalized at an Intensive Care Unit. Three friction techniques were executed in the one-way, two-way and centrifugal sense, individually, three times on each table, during alternate weeks. For each patient unit and friction technique, a single table and three sides of cloth were used, moistened with 70% (w/v) alcohol. The organic matter was detected through the presence of adenosine triphosphate by bioluminescence, using 3M(tm) Clean-Trace(tm) ATP Systems. For each technique, 13 samples were collected before and 13 after the cleaning/disinfection process, totaling 78 samples of adenosine triphosphate by bioluminescence. No statistically significant difference was found among the removal techniques of organic matter. This study demonstrated that none of the three surface friction methods was better than the other to remove organic matter. Nevertheless, further research is needed in which other cleaning/disinfection indicators and surfaces are considered.

scholarly journals EXAMINING THE PROCESS OF DECOMPOSITION AND CARBON CYCLING IN 'FADAMA' COASTAL WETLANDS: A CASE STUDY OF HEAPING WETLANDS ECOSYSTEM

2020 ◽  
Vol 4 (3) ◽  
pp. 10-16
Author(s):  
George Dasat Shwamyil ◽  
G. Danjuma ◽  
E. S. Chundusu
Keyword(s):  
Organic Matter ◽  
Ecosystem Services ◽  
Carbon Cycling ◽  
Carbon Capture ◽  
Carbon Capture And Storage ◽  
Wetland Soil ◽  
Low Oxygen ◽  
Decomposition Of Organic Matter ◽  
Plateau State

Wetlands provide several ecosystem services including carbon capture and storage, water filtration, nutrient cycling, and support agriculture among others. The biogeochemical process and decomposition parameters in ‘Fadama' wetland soils comprising of Gada biyu, Pwomol and Kpang referred to as sites A, B, and C respectively all of Heipang District in Barkin Ladi, Plateau State was investigated using standard operating procedures (SOP). Results of investigations revealed that soils from Kpang had slightly higher water content (34.52%) than those from Pwomol (33.48%) and Gada biyu (32.03%). While soils from Gada biyu had the highest solid organic matter (SOM) (10.79%) followed by Pwomol (8.15%) as Kpang had the least (7.85%). Gada biyu soils had the lowest Phenol oxidases activity (1536.56 nmol dicq g-1 h-1) while those from Pwomol (5340.44 nmol dicq g-1 h-1) was highest. All sites had similar concentrations of soil phenolics (76.58 µg g-1, 79.98µg g-1, and 83.25µg g-1). The activity of hydrolyses (β-glucosidase) in Gada biyu soil (2.93 nmol g-1 min-1) was lower than those from Pwomol (6.13 nmol g-1 min-1). These parameters indicate the level of biogeochemical processes in the soil at each site. Gada biyu had the highest rate of CH4 (0.84 ug g-1h-1) flux. Decomposition of organic matter, carbon cycling and greenhouse gas storage in wetland soil, is due to the anoxic condition comprising of low oxygen availability, cool temperatures, anaerobic conditions, reduced microbial activity, and the quality of organic matter substrates in such soils.  Anthropogenic disturbances affecting wetlands must be discouraged to promote vital ecosystem services.

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