Soil Organic Matter

1999 ◽  
Author(s):  
Robert F. Keefer
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Higher Plants ◽  
Krebs Cycle ◽  
Dry Weight ◽  
Animal Remains ◽  
Adsorption Of Water ◽  
Phenolic Substances ◽  
Plant Polymer ◽  
Almost All

Soil organic matter (SOM) is probably the most important constituent of soils. The effect of SOM on soil properties far exceeds the relative percentage of this material in soils. The small amount of organic matter in soils, usually from 1 to 5%, is very important in providing a reserve food source for microorganisms and higher plants. Almost all properties of SOM are beneficial for plant growth. Soil organic matter can be defined as a complex, heterogeneous mixture of plant and animal remains in various stages of decay, microbial cells—both living and dead—microbially synthesized compounds, and derivatives of all of the above through microbial activity. Soil organic matter is probably the most complex of all naturally occurring substances. Some compounds in SOM are distinctive to soil and are not present in plants or animals. By examining the composition of SOM, one can see why it is such a complex material. The following compounds have been isolated from chemical SOM extracts: . . . 1. Carbohydrates (sugars, polysaccharides)—about 75% of dry weight 2. Lignin (a plant polymer of phenyl propane units) 3. Proteins (combinations of amino acids) 4. Hydrocarbons—fats, waxes, resins, and oils 5. Tannins (phenolic substances) 6. Pigments (chlorophyll) 7. Organic acids (many in the biochemical Krebs cycle) 8. Miscellaneous compounds—includes organic P, organic S, polynuclear hydrocarbons, nucleic acid derivatives, alcohols, aldehydes, esters, etc. . . . Whenever organic materials are added to a soil the physical properties of soil structure, water-holding capacity, and soil color are changed. The extent of change in these properties depends on the amount and type of organic material added, the soil microorganisms present in the soil, and the speed at which decomposition occurs. Aggregation and granulation (crumb formation) is increased by polysaccharides produced by microorganisms during decomposition. This improves soil tilth (ability to work the soil) and helps stabilize the soil crumbs. The ability of a soil to hold water is greatly increased by addition of SOM. This results in greater infiltration (water moving into the soil) and adsorption of water by the SOM, with consequently less erosion and loss of soil particles and fertility.

scholarly journals Growth and Yield of Chili Pepper under Different Time Application of Wedelia (Wedelia trilobata) and Siam Weed (Chromolaena odorata) Organic Fertilizers

2017 ◽  
Author(s):  
Nanik Setyowati ◽  
Zainal Muktamar ◽  
Silma Oktiasa ◽  
Dwi W. Ganefianti
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Plant Height ◽  
Organic Fertilizer ◽  
Dry Weight ◽  
Chili Pepper ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Chromolaena Odorata ◽  
Wedelia Trilobata

Low content of soil organic matter and low availability of nutrients in Ultisol are major constraints of this soil to support growth and development of chili pepper. Application of organic fertilizer is required to increase content of soil organic matter as well as to improve other chemical, biological, physical properties of this soil. Wedelia (Wedelia trilobata) and Siam Weed (Chromolaena odorata) are potential sources of organic fertilizer. The aim of this study was to compare growth and yield of chili pepper under different time application of Wedelia and Siam Weed based organic fertilizers. Greenhouse house experiment was conducted employing Completely Randomized Design with 2 factors namely Wedelia and Siam Weed composts as first factor and 5 (five) different time of application as second factor. Each treatment was replicated 5 times. The study showed that most variables observed in this experiment were not affected by types of compost. Only were plant height, canopy width and dry weight of biomass significant difference between the two composts. Siam weed compost applied two weeks before planting resulted in plant canopy wider than Wedelia compost. However, Wedelia compost applied at planting resulted in longer chili pepper as compared to Siam weed compost. The experiment also revealed that Wedelia compost produced higher plant height and root dry weight as compared to Siam weed compost.

scholarly journals Lability classification of soil organic matter in the northern permafrost region

2020 ◽  
Vol 17 (2) ◽  
pp. 361-379 ◽  
Author(s):  
Peter Kuhry ◽  
Jiří Bárta ◽  
Daan Blok ◽  
Bo Elberling ◽  
Samuel Faucherre ◽  
...  
Keyword(s):  
Organic Matter ◽  
Global Warming ◽  
Soil Organic Matter ◽  
Dry Weight ◽  
Soil Samples ◽  
Co2 Production ◽  
Permafrost Region ◽  
Production Rates ◽  
Incubation Experiments ◽  
The Relationship

Abstract. The large stocks of soil organic carbon (SOC) in soils and deposits of the northern permafrost region are sensitive to global warming and permafrost thawing. The potential release of this carbon (C) as greenhouse gases to the atmosphere does not only depend on the total quantity of soil organic matter (SOM) affected by warming and thawing, but it also depends on its lability (i.e., the rate at which it will decay). In this study we develop a simple and robust classification scheme of SOM lability for the main types of soils and deposits in the northern permafrost region. The classification is based on widely available soil geochemical parameters and landscape unit classes, which makes it useful for upscaling to the entire northern permafrost region. We have analyzed the relationship between C content and C-CO2 production rates of soil samples in two different types of laboratory incubation experiments. In one experiment, ca. 240 soil samples from four study areas were incubated using the same protocol (at 5 ∘C, aerobically) over a period of 1 year. Here we present C release rates measured on day 343 of incubation. These long-term results are compared to those obtained from short-term incubations of ca. 1000 samples (at 12 ∘C, aerobically) from an additional three study areas. In these experiments, C-CO2 production rates were measured over the first 4 d of incubation. We have focused our analyses on the relationship between C-CO2 production per gram dry weight per day (µgC-CO2 gdw−1 d−1) and C content (%C of dry weight) in the samples, but we show that relationships are consistent when using C ∕ N ratios or different production units such as µgC per gram soil C per day (µgC-CO2 gC−1 d−1) or per cm3 of soil per day (µgC-CO2 cm−3 d−1). C content of the samples is positively correlated to C-CO2 production rates but explains less than 50 % of the observed variability when the full datasets are considered. A partitioning of the data into landscape units greatly reduces variance and provides consistent results between incubation experiments. These results indicate that relative SOM lability decreases in the order of Late Holocene eolian deposits to alluvial deposits and mineral soils (including peaty wetlands) to Pleistocene yedoma deposits to C-enriched pockets in cryoturbated soils to peat deposits. Thus, three of the most important SOC storage classes in the northern permafrost region (yedoma, cryoturbated soils and peatlands) show low relative SOM lability. Previous research has suggested that SOM in these pools is relatively undecomposed, and the reasons for the observed low rates of decomposition in our experiments need urgent attention if we want to better constrain the magnitude of the thawing permafrost carbon feedback on global warming.

Does biochar contribute to soil organic matter accumulation? – A tropical perspective

2021 ◽  
Author(s):  
Laura Sophie Schnee ◽  
Albert Ngakou ◽  
Juliane Filser
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Meta Analysis ◽  
Soil Nutrient ◽  
Nutrient Retention ◽  
Dry Weight ◽  
Nutrient Status ◽  
Tropical Soils ◽  
Added Value ◽  
Soil Conditions

<p>Tropical soils are often deeply weathered and vulnerable to degradation. Biochar appears a promising means to improve soil quality while sequestering carbon into the soil. Yet, sustainable soil amelioration depends on stable soil organic matter (SOM) stocks for nutrient retention, water uptake and as habitat for soil life. In a literature meta-analysis, we investigated, if biochar amendment to tropical soils led to SOM increases additional to biochar C. We found a mean additional C accumulation (MAC) of 0.29% soil dry weight (% dw). MAC was independent of study duration, climate, and biochar addition rate, but strongly linked to soil type and nutrient status prior to the experiment: In Nitisols, MAC was highest (0.99% dw) and initial C and N contents were higher in these soils. MAC was slightly negative in Ferralsols and Oxisols (– 0.01% dw and –0.2% dw respectively). MAC as a percentage of initial C content was < 50% for most soil types, but –50% in Ferralsols, Oxisols and Ultisols. Changes to soil microbiomes were more conclusive and included elevated enzyme activities and shifts from bacterial to fungi dominated microbiomes. We conclude that soil nutrient status prior to amendment, which is often linked to microbial activity, determines if the alteration of soil conditions caused by the biochar can be buffered ecologically, so that fresh organic residues are transformed into SOM. Additionally, we remarked that research on biochar – SOM interactions in tropical soils largely depends on cooperations with institutions from North America and Europe for funding and analytical infrastructure. Researchers, institutions, and funding bodies need to be creative and cautious to realise equitable participation of all partners in international research projects designed to render added value for societies around the world.</p>

scholarly journals Soil Organic Matter Content Effects on Apple Root Dynamics

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 842D-842
Author(s):  
Dario Stefanelli* ◽  
Giovambattista Sorrenti ◽  
Ronald L. Perry
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Root Length ◽  
Organic Matter Content ◽  
Mineral Fertilizer ◽  
Dry Weight ◽  
Matter Content ◽  
Root Dynamics ◽  
Shoot Ratio ◽  
Root Shoot Ratio

Soil organic matter is a critical component which is fundamental in plant growth. Several soil factors are influenced by organic matter such as slow release of nutrients, increased water holding capacity, improved soil physical characteristics and improved environment for soil microorganisms. The aim of this work is to investigate the physical effect of organic matter content in the soil on apple root growth and development. Twenty five two-year old apple trees (Malus domestica, Borkh) cv. `Buckeye Gala' on M.9 NAKB 337 rootstock were planted in completely transparent acrylic boxes. Plants have been grown in a green house to avoid external rain in a complete randomized design. Trees were planted in a sandy-mix soil amended with soil high in organic matter, “muck”, at four incremental levels. Treatments compared were a control (sandy soil with 0% organic matter) and 1%, 2%, 4% and 8% soil organic matter. The amount of water applied by automatic drip irrigation was comparable for all the treatments to avoid high fluctuation of soil moisture on root dynamics. All treatments have been fertilized with the same amount of mineral fertilizer to avoid the nutrition effect on root dynamics. Digital photos of roots were taken to study their dynamics every one to two weeks during a period of five months. Roots have been highlighted with Photoshop and then analyzed with WinRhizo to measure root length, area, lifespan and dynamics. At the end of the growing period plants have been harvested and fresh and dry weight was evaluated to asses the root/shoot ratio. The effects of the treatments on root length, area, lifespan and dynamics, and root/shoot ratio will be discussed.

scholarly journals Ecological Value Of Soil Organic Matter (SOM) at Tropical Evergreen Aglaia-Streblus Forest of Meru Betiri National Park, East Java, Indonesia

2017 ◽  
Vol 21 (3) ◽  
pp. 129-140
Author(s):  
Hari Sulistiyowati ◽  
Sugeng Winarso ◽  
Damasa Macandog ◽  
Rachel Sotto ◽  
Nestor Baguinon ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Tropical Forest ◽  
Forest Soil ◽  
National Park ◽  
Dry Weight ◽  
Biogeochemical Cycles ◽  
Element Content ◽  
Ecological Value ◽  
Organic C

As part of carbon pools, forest soil stores soil organic matter (SOM) that contains many elements including organic C, N, P, and K. These elements contribute nutrients for biogeochemical cycles within the ecosystem. This study was done to determine the ecological value of forest soil organic matter at tropical evergreen Aglaia-Streblus forest of Meru Betiri National Park (MBNP), East Java, Indonesia. The data were sampled along gradient topography in Pringtali tropical forest of TMBNP. Direct measurements of soil moisture, temperature, and pH were taken in the field. The soil samples were extracted from 6 points of soil solum using soil auger, and then oven-dried to get value of dry-weight. The elements content of organic C, N, P, and K were analyzed and estimated at the laboratory. The ecoval of SOM was appraised using developed ecological valuation tool. The result showed that SOM contributed higher ecoval of organic C (66.03 Mg ha-1) than other elements. Compared to P and K elements, N had the highest stock of element content. However, comparing to other two tropical forest ecosystems of Asia the ecoval of SOM elements in TMBNP was relatively low because of its natural geomorphological features.The ecoval of SOM elements in TMBNP was relatively low because of its natural geomorphological features. The ecovals contributed about 2.440,64 - 6.955,50 USD or  31.271.923,73 - 89.120.837,23  IDR per hectare of ecological value (d) to the ecosystem. This value was mainly contributed by organic C stock in the TMBNP forest SOM. It means the forest SOM had higher element content of organic C than N, P, and K elements. This d value is an indicator for TMBNP to protect the SOM elements meaning protecting their resources to sustain the biogeochemical cycles in the forest ecosystem. All the management and policy correlated to this protected area should consider this valuable information for their plan and actions.

scholarly journals Potential methane production and oxidation along the soil chronosequence of the Rotmoos glacier forefield

2019 ◽  
Vol 70 (1) ◽  
pp. 19-31
Author(s):  
Eva Maria Prem ◽  
Nadine Praeg ◽  
Katrin Hofmann ◽  
Andreas Otto Wagner ◽  
Paul Illmer
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Methane Oxidation ◽  
Methane Production ◽  
Dry Weight ◽  
Enzymatic Properties ◽  
Nitrate Content ◽  
Climate Conditions ◽  
Glacier Forefield ◽  
Soil Age

SummaryFive differently developed soils aged 6, 35, 80, 150, and >5000 years with the same bedrock and the same (current) climate conditions were chosen to assess abiotic and enzymatic properties as well as methanogenic and methanotrophic activities. Most abiotic properties (dry weight, pH, soil organic matter, and ammonium content), enzyme activities (dehydrogenase [DH] activity, ammonification [AM] rate, dimethylsulfoxide reduction), and potential methane oxidation (PoMO) per gram of dry weight (DW) increased with soil age. In contrast, potential methane production (PoMP) as well as the nitrate content per gram of DW and most enzymatic properties per gram of soil organic matter (SOM) did not increase with soil age but reached its maximum in the middle-aged soils (80–150 years). Our results show that (i) microbial activity does not consequently increase with SOM content/soil age; (ii) methane production can be measured in undeveloped soils, whereas methane oxidation is more restricted to fully developed soils; and (iii) certain soil modifications (change in water content, ammonium addition) could influence potential methane production/oxidation. When considering the concurrent release of raw soil because of the melting of perpetual ice, these data could help to better understand and assess the consequences of global change.

scholarly journals Lability classification of soil organic matter in the northern permafrost region

2019 ◽  
Author(s):  
Peter Kuhry ◽  
Jiři Bárta ◽  
Daan Blok ◽  
Bo Elberling ◽  
Samuel Faucherre ◽  
...  
Keyword(s):  
Organic Matter ◽  
Global Warming ◽  
Soil Organic Matter ◽  
Dry Weight ◽  
Soil Samples ◽  
Long Term Results ◽  
Co2 Production ◽  
Permafrost Region ◽  
Production Rates ◽  
The Relationship

Abstract. The large stocks of soil organic carbon (SOC) in soils and deposits of the northern permafrost region are sensitive to global warming and permafrost thawing. The potential release of this carbon (C) as greenhouse gases to the atmosphere does not only depend on the total quantity of soil organic matter (SOM) affected by warming and thawing, but also on its lability (i.e. the rate at which it will decay). In this study we develop a simple and robust classification scheme of SOM lability for the main types of soils and deposits of the northern permafrost region. The classification is based on widely available soil geochemical parameters and landscape unit classes, which makes it useful for upscaling to the entire northern permafrost region. We have analyzed the relationship between C content and C-CO2 production rates of soil samples in two different types of laboratory incubation experiment. In one experiment, c. 240 soil samples from four study areas were incubated using the same protocol (at 5 °C, aerobically) over a period of one year. Here we present C release rates measured on day 343 of incubation. These long-term results are compared to those obtained from short-term incubations of c. 1000 samples (at 12 °C, aerobically) from an additional three study areas. In these experiments, C-CO2 production rates were measured over the first four days of incubation. We have focused our analyses on the relationship between C-CO2 production per gram dry weight per day (µgC-CO2 gdw−1 d−1) and C content (%C of dry weight) in the samples, but show that relationships are consistent when using C / N ratios or different production units such as µgC per gram soil C per day (µgC-CO2 gC−1 d−1) or per cm alluvial deposits and mineral upland soils (including peaty wetlands) > Pleistocene Yedoma deposits > C-enriched pockets in cryoturbated soils > peat deposits. Thus, three of the most important SOC storage classes in the northern permafrost region (Yedoma, cryoturbated soils and peatlands) show low relative SOM lability. Previous research has suggested that SOM in these pools is relatively undecomposed and the reasons for the observed resistance to decomposition in our experiments needs urgent attention if we want to better constrain the magnitude of the thawing permafrost carbon feedback on global warming.

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