Question

when we burn soil why it's colour change into red / orange??​

Answer 1

Answer:-

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As a soil have very high nutrients content in it that is the reason when it react with fire it becomes red/orange.

Reaseon:-

The soil macronutrients are the elements considered essential for plant growth and nutrition needed in relatively large quantities. They are most likely to impact site productivity and vegetation dynamics.

• Some nutrient dynamics are more sensitive to fires than others. The concentration of potassium, calcium, and magnesium ions in the soil can increase or be unaffected by fires whereas nitrogen and sulphur often decrease

Soil Microbes and Fire

• The effects of fire on soil microbes is dependent to a large extent upon fire intensity. The responses of soil microbes to fires range from no detectable effect in low intensity fires to total sterilization of the surface layers of soil in very hot wildfires (see Joergensen and Hodges 1970; and Renbuss et al. 1973). This early work focused primarily on the abundance of microorganisms and not their activity levels. This is interesting because workers have observed that although there is a decrease in abundance of microbes following fire, the remaining microbes can have levels of activity that are greater than that of the microbial community prior to the fire (Poth et al. 1995). These authors found that the increased rates of microbial processes, such as denitrification and production of methane and carbon dioxide, persisted for one year following fire.

Macroinvertebrates and Fire

• The general pattern of macroinvertebrate responses to fire is often driven by changes in habitat structure, or by changes in the amount or the quality of food resources. Whenever fire affects vegetation, temperature or moisture, or the nutrient status of a soil, there is potential for impact on the soil invertebrate community. Some arthropod groups increased in abundance but most decreased soon after fire.

• Soil%20insectsA study of litter dwelling and soil dwelling macroinvertebrates showed that the density of macroinvertebrates was significantly reduced one year after a prescribed fire (Kalisz and Powell 2000). Reduction in the number of beetle larvae accounted for a large proportion of the difference following fire, and the authors proposed that repeated fire in a single location could potentially have long-term negative effects on beetle populations and on the functions these beetles perform within the system.

Fire Effects on Soil Organic Matter

• Soil organic matter (SOM), or humus, contains significant supplies of nitrogen (N), phosphorus, and sulfur and thus is an important storehouse of plant nutrients. SOM is approximately 50% carbon (C) by mass. SOM also increases soil water-holding capacity, stabilizes soil aggregates, and decreases the toxicity of aluminum to plants (Stevenson 1994).

Biodegradation of Organic Forms of Carbon and Nitrogen as Affected by Fire

• Fire appears to increase the amount and biodegradation rate of readily decomposable soil organic matter while simultaneously increasing the resistance of the stable portion of soil organic matter. The increased decomposition activity that immediately follows fire is likely a result of increased levels of readily decomposable C as well as increased pH, the conversion of nutrients to soluble forms, increased soil temperature, and increased water availability to microbes due to lessened plant water demands. ”

Charcoal (“Black Carbon”) and Its Effect on Soil Properties

• Charcoal, when applied to soil in amounts expected after wildfire, enhanced plant nitrogen uptake, altered the competitive balance between plant species (including ericaceous species), and stimulated moss and fern production in a Swedish boreal forest ecosystem. These effects were attributed to charcoal’s ability to bind and deactivate phenolic compounds in the soil (Wardle et al. 1998).

Fire Effects on the Chemical Properties of Soil Organic Matter

• Heating soil organic matter in the laboratory produces rapid losses of carbohydrates and proteins and eventually produces residues rich in aromatic compounds. The aromatic compounds formed include aromatic forms of nitrogen, which may be responsible for the reduced N availability observed in some burned areas. N is the major limiting nutrient in most forests. Hydrophobic polymers are also formed upon heating, and these are probably responsible for the soil hydrophobicity that is observed after fire.

Effects of Fire on Soil Physical Properties

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• Fire may alter several physical soil properties, such as soil structure, texture, porosity, wetability, infiltration rates, and water holding capacity. The extent of fire effects on these soil physical properties depends on fire intensity, fire severity, and fire frequency. Low intensity fires do not cause enough soil heating to produce significant changes to soil physical properties.

Hope it help you out ✌ ☺....

Answer 2

Hello!

I don't think it's true for every soil

You may be asking for pure clay from which brick is formed

Actually it contains silica

Silica I guess you may be knowing

When you heat silica then being a molecule have electrons which excite to hi