
	Where results make sense

Topic: Soil organic matter

	Albrecht: Loss of Soil Organic Matter and Its Restoration
		As a consequence of this loss in organic matter, the soil structure was modified to an extent that might be represented by reducing the number of granules that were the size of particles of sand by 11 percent and increasing the number that were the size of clay particles by 5.5 percent.
		Organic matter itself is predominantly of a colloidal form resembling that of clay, which is the main chemically active fraction of the soil.
		If the soils that have lost their organic matter are to be restored, the loss of minerals, which has probably been fully as great, must be taken into account, and provision must be made to restore these mineral deficiencies before attempting to grow crops for the sake of adding organic matter.
	www.soilandhealth.org /01aglibrary/010120albrecht.usdayrbk/lsom.html (5998 words)

	GRDC - Research Summaries - Functions of soil organic matter and the effect on soil properties - Introduction
		For soils with 4% clay, the lower and upper limit was proposed to be at 1% and 1.5% and for soils with 38% the respective limits were 3.5 and 4.4%.
		Organic Matter, Active Fraction: The highly dynamic or labile portion of soil organic matter that is readily available to soil organisms.
		Organic Matter, Stabilized Organic Matter: The pool of soil organic matter that is resistant to biological degradation because it is either physically or chemically inaccessible to microbial activity.
	www.serve.com /treepower/soils/organicmatter.html (2640 words)

	organic
		Organic matter in soils is represented by plant debris or litter in various stages of decomposition through to humus and includes the living organisms in the soil.
		Soil organic matter represents a major pool of carbon within the biosphere, estimated at about 1400 x 1015 g globally, roughly twice that in atmospheric CO SOM may act as both a source and sink of carbon during global environmental change.
		The finer textured soils typically show a larger initial flush of microbial activity that is followed by greater incorporation and stabilization of organic matter in the soil than found in coarser textured soils.
	www.soils.wisc.edu /courses/SS325/organic.htm (4985 words)

	FS-783 - Soil Organic Matter (Site not responding. Last check: 2007-10-29)
		Soil organic matter is the part of the soil that consists of plant and animal residues in various stages of decay.
		Organic matter, which helps to maintain or improve the physical condition of the soil, increases the soil's capacity for water infiltration and water holding.
		Organic matter, an essential component of a healthy soil, is in a constant state of transition, continually breaking down and releasing finer, more-decomposed particles.
	www.agnr.umd.edu /MCE/Publications/Publication.cfm?ID=493 (1601 words)

	Soil Organic Matter
		Organic matter helps the soil hold water and supplies nutrients, which are crucial for crop production; it also protects against erosion and helps support a healthy and diverse set of microscopic plants and animals.
		Organic matter content, erosion, soil salinity, and soil biological condition are key indicators of soil quality, reflecting the effect of agriculture on soils and the influence of changing crop and soil management practices.
		Soil organic matter is usually measured as the percentage of organic matter (by dry weight) in the top 4–6 inches of the soil, where human activities have most influence on soil condition.
	www.heinzctr.org /ecosystems/farm/soil_orgnc.shtml (286 words)

	Soil Organic Matter
		Organic matter is important in the soil to improve soil structure, nutrient holding capacity, water holding capacity, and infiltration.
		The texture of the soil (sandy, clay, etc) may affect the results of this test also, and lead to either an under- or overestimation of organic matter content.
		Also, we have found that at the upper end of the organic matter scale, this test does not distinguish between soil that is 3% organic matter, and compost amended samples that are 5%, 10%, or even higher.
	www.oznet.ksu.edu /kswater/images/soil_organic_matter.htm (870 words)

	Lab10chap1
		Soil health or quality is the soil's fitness to support crop growth without resulting in soil degradation or otherwise harming the environment.
		Organic matter is added to the soil as well as the potential for nutrients such as nitrogen.
		If organic material is added to soil that has a wide carbon to nitrogen ratio, the nitrogen in the soil will be used by the organisms to decompose the organic matter.
	www.soils.umn.edu /academics/classes/soil2125/doc/s10chap1.htm (1617 words)

	DPIW - Soil Organic Matter
		Organic matter is widely regarded as a vital component of a healthy soil.
		The amount of carbon (the measure of organic matter) in a soil depends on a range of factors, and reflects the balance between accumulation and breakdown.
		The ratio of carbon:nitrogen:sulphur:phosphorus in organic matter is roughly 100:10:1.5:1.5.
	www.dpiw.tas.gov.au /inter.nsf/WebPages/TPRY-5YW6YZ?open (1229 words)

	What Does Organic Matter Do In Soil?
		Organic matter serves as a reservoir of nutrients and water in the soil, aids in reducing compaction and surface crusting, and increases water infiltration into the soil.
		An acre of soil measured to a depth of 6 inches weighs approximately 2,000,000 pounds, which means that 1 percent organic matter in the soil would weigh about 20,000 pounds per acre.
		Soils that formed under prairie vegetation usually have native organic matter levels at least twice as high as those formed under forest vegetation.
	www.noble.org /Ag/Soils/OrganicMatter/Index.htm (962 words)

	Soil organic matter (Site not responding. Last check: 2007-10-29)
		Soil organic matter (OM) is made up of the decaying remains of plants and animals.
		Organic matter is composed of carbon compounds which when heated to high temperatures are converted to CO and water.
		The organic matter in the soil and some volatile, non-organic chemicals from the sample are given off as gases.
	www.geog.plym.ac.uk /labskills/ompg.htm (223 words)

	Organic Matter Management - Soil Scientist
		Organic matter is the vast array of carbon compounds in soil.
		Organic matter also affects nutrient cycles by chelating (chemically holding on to) nutrients, and preventing them from becoming insoluble and therefore unavailable to plants.
		The amount of organic matter in soil is the result of two processes: the addition of organic matter (roots, surface residue, manure, etc.), and the loss of organic matter through decomposition.
	www.extension.umn.edu /distribution/cropsystems/components/7402_02.html (2137 words)

	Soil Organic Matter (SOM) and Organic Carbon (SOC) in Phosphate Mining Reclamation.
		Soil Organic Matter: For the purposes of this discussion, Soil Organic Matter (SOM) is defined as all organic materials found in soils irrespective of origin or state of decomposition.
		Humus (stabilized organic matter): This pool of SOM is resistant to biological degradation because it is either physically (e.g., lignins contained in woody biomass) or chemically (e.g., humic acids) less accessible to microbial activity.
		For soils with 4% clay, the lower and upper limit was proposed to be at 1% and 1.5% and for soils with 38% clays (still significantly below that of clay settling areas) the respective limits were 3.5% and 4.4%.
	www.treepower.org /soils/soilorganicmatter.html (2681 words)

	Organic Matter Explained
		The population of organisms that is supported by soil organic matter is of immeasurable benefit to plants.
		Organic matter is so important because it increases the life span of any given soil by inhibiting weathering forces such as wind and water from destroying it beyond its most productive stage.
		Composted manures are an excellent amendment to soils because of the high percentage of organic matter they contain, but they must be used in larger quantities because of their relatively low nitrogen content.
	www.microsoil.com /OrganicMatter.htm (940 words)

	CASFS - Building Fertile Soil (Site not responding. Last check: 2007-10-29)
		Organic soil amendments such as compost, manure, cover crops, and fertilizers derived from non-synthetic sources can improve soil quality while providing a source of nutrients that lasts through the growing season.
		Organic matter, made up of decomposed plant and animal material, can help replenish nutrients and at the same time improve soil structure, making it easier to work and a more hospitable place for plants to thrive.
		Fertilizers from organic sources may be especially important for soil low in organic matter, or during the first seasons that you reduce or eliminate the use of synthetic chemical fertilizers.
	zzyx.ucsc.edu /casfs/gardenideas/soilfert.html (2997 words)

	DPIWE - Soil Organic Matter (Site not responding. Last check: 2007-10-29)
		The amount of carbon (the measure of organic matter) in a soil depends on a range of factors, and reflects the balance between accumulation and breakdown.
		Organic matter can be considered a pivotal component of the soil because of its role in physical, chemical and biological processes (Table 2).
		The ratio of carbon:nitrogen:sulphur:phosphorus in organic matter is roughly 100:10:1.5:1.5.
	www.dpiwe.tas.gov.au /inter.nsf/WebPages/TPRY-5YW6YZ?open (1227 words)

	Soilhealth.com - Soil Organic Matter (Site not responding. Last check: 2007-10-29)
		Organic matter is anything that contains carbon compounds that were formed by living organisms.
		As these compounds are decomposed, the organic matter in soil is transformed and gradually changes so that eventually it is no longer recognizable as part of the original plant.
		All of these changes are related to the way organic matter is decomposed when it is incorporated into soil and to the particular type of organic matter used.
	www.agric.uwa.edu.au /soils/soilhealth/organic (1043 words)

	AGVISE Laboratories -- Soil Organic Matter
		Due to the importance of organic matter in the soil, the number of requests from GLP customers to test the organic matter level has increased markedly in the past 5 years.
		Soils with a high clay content generally have a higher organic matter content, due to slower decomposition of organic matter.
		Soils with a high bulk density are likely to have low organic matter levels and are more prone to nutrient leaching.
	www.agviselabs.com /tech_art/om.php (571 words)

	Organic Matter
		For simplicity, organic matter can be divided into two major categories: stabilized organic matter which is highly decomposed and stable, and the active fraction which is being actively used and transformed by living plants, animals, and microbes.
		The active organic matter, and the microbes that feed on it, are central to nutrient cycles.
		One quarter of the organic matter produced by corn or soybeans is produces by the roots.
	soils.umn.edu /academics/classes/soil5611/content/OrganicMatter (2496 words)

	Soil organic matter
		The amount of soil organic matter in a particular location is primarily due to natural factors like temperature (cool locations accumulate more organic matter), soil texture (clayey and silty soils tend to have more organic matter than sandy soils), and the drainage (poor drainage promotes soil organic matter build up).
		Soil organic matter is made up of plant and animal residues in different stages of decomposition, cells of soil microorganisms, and substances that are so well-decomposed it’s impossible to tell what they were to begin with.
		Soil must also be managed to minimize the loss of organic matter through oxidation (from aggressive tillage) and erosion (from ground left bare).
	www.uvm.edu /~pass/grubinger/factsheets/soilorganicmatter.html (884 words)

	Soil Organic Matter Content & Nitrogen Levels
		Soil nutrient analysis by way of ion specific electrodes is somewhat problematic due to the large number of variables associated with soils (i.e., texture, moisture, nutrient levels, organic matter).
		After the soils were selected the organic matter content of the soils were determined using a previously developed reflectance-bases organic matter sensor (Shonk 1990).
		However, because of the large variation in stabilization times from one trial to the next it is difficult to state with a large amount of certainty that the different organic matter levels of the soils are the cause of the variation in the time required for the readings to stabilize.
	www.agriculture.purdue.edu /ssmc/Frames/nitrate.html (2488 words)

	Soil Organic Matter, Green Manures and Cover Crops For Nematode Management (Site not responding. Last check: 2007-10-29)
		Vegetables, flowers and landscape plants grown in soil that is high in organic matter often are damaged less by nematodes than are plants in soil of low organic matter content.
		Soil organic matter is any material in the soil that was originally produced by living organisms.
		Humus and partly decomposed soil organic matter can greatly increase the water- and nutrient-holding capacities of sandy soils, reducing some of the major stresses which magnify the effects of nematode damage to roots.
	edis.ifas.ufl.edu /VH037 (1809 words)

	Soilhealth.com - Soil Organic Matter
		Organic matter is anything that contains carbon compounds that were formed by living organisms.
		As these compounds are decomposed, the organic matter in soil is transformed and gradually changes so that eventually it is no longer recognizable as part of the original plant.
		All of these changes are related to the way organic matter is decomposed when it is incorporated into soil and to the particular type of organic matter used.
	www.soilhealth.com /organic (1054 words)

	University of Adelaide, Organic Matter
		The retention of carbon in soils is important for the global cycling of carbon and for sustained fertility and stability of soils.
		Organic materials in soils have been characterised by a range of spectroscopic and wet chemical procedures with emphasis on solid state 13C CP MAS NMR.
		The influence of sodicity and salinity on the decomposition of organic matter was examined by incubation in soils with different levels of sodicity and salinity.
	www.waite.adelaide.edu.au /Soil_Water/organic.html (1106 words)

	DPIW - Organic Matter
		The problem with farming is that more organic matter is removed from the system, in the form of fresh produce, than is returned to the system, in the form of plant residues, compost or manures.
		Grass covers are effective because they stop the loss of organic matter by controlling topsoil erosion and their large root mass serves as a readily available input of organic matter.
		The use of off-farm sources of organic matter will help to build or maintain organic matter in depleted soils where it is difficult to make progress merely by retaining crop residues.
	www.dpiw.tas.gov.au /inter.nsf/WebPages/TTAR-5DT32C?open (528 words)

	Soil Organic Matter, Know Your Soil, Bulletin #2288
		Organic matter affects both chemical and physical properties of the soil.
		Practices That Reduce Organic Matter: Tillage is one practice that reduces the organic matter in the soil.
		Conservation practices that protect the soil from erosion are important to keep organic matter in place, although they will not add much organic matter to the soil.
	www.umext.maine.edu /onlinepubs/htmpubs/2288.htm (826 words)

	Soil Organic Matter \| NRCS SQ
		Managing soil organic matter is the key to air and water quality (Figure 1).
		Soil conservation policy in the United States stems from the devastating erosion events of the 1920s and ’30s.
		Because organic matter enhances water and nutrient holding capacity and improves soil structure, managing for soil carbon can enhance productivity and environmental quality, and can reduce the severity and costs of natural phenomena, such as drought, flood, and disease.
	www.soils.usda.gov /sqi/concepts/soil_organic_matter/som.html (312 words)

	Soil Organic Matter
		Soil samples from three sites contrasting in vegetation were analysed for microbial biomass-C and N, soil nutrient concentrations (C, N and P), as well as other key soil physical and chemical properties.
		The Tara Hills soil organic C and N, and microbial biomass C and N data indicates that the tall tussock association, which occupies a higher colder part of the environment, naturally supports SOM of lesser quality than the short tussock associations.
		But there were differences between soil depths in the amount of CO respired per g soil C. It appears that the greater labile organic matter inputs into surface soils resulted in greater availability of metabolically accessible compounds compared to the soils at 5-10 and 10-20 cm depths.
	www.tussocks.net.nz /pastoral/soiorgmat_sum.html (930 words)

	Understanding the Soil
		Soil moves continually in a natural cycle aided by oxygen, water, minerals and decomposing animal and plant matter.
		Soil plasma is the liquid portion of the soil.
		Soil plasma is that substance in the soil that can spin catabolized remnants of former life into vital threads that are woven together into the fabric of new life through the processes of anabolism.
	www.rain.org /~sals/Petrik.html (2804 words)

Try your search on: Qwika (all wikis)