The mass fraction of ash content of peat and peat soil horizons (A), as a percentage, is calculated by the formula. The chemical composition of the ash part of peat

Determination of the ash content of peat and products of its processing is carried out according to GOST 11306-2013.

For peat and peat products for fuel purposes, the method consists in ashing weighed portions of products and calcining the ash residue in a muffle furnace in crucibles at a temperature of (800±25)°C.

For peat fertilizers, soils and other types of peat products for agricultural and environmental purposes, the ashing of product samples and the calcination of the ash residue in a muffle furnace in crucibles is carried out at a temperature of (525 ± 25) ° С.

In this case, the mass loss upon ignition is taken as the mass fraction of organic matter.

The determination of the ash content is carried out in parallel in two weighed portions of an analytical sample prepared in accordance with GOST 11303-2013. Samples weighing 2-8 g fall asleep in pre-weighed crucibles.

Determination of the ash content of peat and peat products for fuel purposes

Crucibles with weighed portions of peat are covered with lids and placed on a muffle furnace under cold or heated to a temperature of 200-250°C. After 15 minutes the door is opened, the lids are removed from the crucibles and the oven is heated to a temperature of (800±25)°C. At this temperature, calcination is continued in a closed muffle furnace until the non-volatile residue is completely ashed for 3 hours.

After calcination, the crucibles with ash are removed from the muffle furnace, cooled on an asbestos sheet for 5 minutes, and then in a desiccator until room temperature and weighed.

To control the crucibles with ash residue additionally calcined for 40 min at a temperature of (800±25)°C. After cooling and weighing, the change in mass is determined. If the change in mass in the direction of decrease or increase is less than 0.005 g, then the test is completed and the last mass is taken for calculation. When the mass decreases by 0.005 g or more, the crucibles with ash are additionally calcined (each for 40 minutes) until the difference in mass during two successive weighings is less than 0.005 g.

Determination of the ash content of peat products for agricultural and environmental purposes

Crucibles with peat weights are closed with lids and placed on a muffle furnace under a cold or heated to a temperature of 200-250 ° C (under the furnace they are filled with crucibles no more than half), close the door. After 15 minutes, open the door, remove the lids from the crucibles, and gradually heat the oven to a temperature of (525 ± 25)°C over 1 hour.

At this temperature, the calcination of the closed muffle furnace is continued until the non-volatile residue is completely ashed (until sparking stops) for 3 hours. Observation is carried out through the viewing hole.

After calcination, the crucibles with ash are removed from the muffle furnace, cooled on an asbestos sheet for 5 minutes, and then in a desiccator to room temperature and weighed. Unburned particles are additionally burned out. To do this, a few drops of hot distilled water with a temperature of more than 90 ° C or a 3% solution of H 2 O 2 are added to the crucibles and re-calcined at a temperature of (525 ± 25) ° C for 1 hour, cooled in a desiccator and weighed to within 0.001 g

The ash content of the analytical sample (A a) is calculated as a percentage according to the formula:

And a \u003d m 1? 100 / m,% (11.7)

where m 1 is the mass of the ash residue, g;

m is the weight of the sample of the tested peat, g.

The ash content of absolutely dry peat (A d) is calculated by the formula:

А d = А a ?100/(100 – W a), % (11.8)

where W a is the moisture content of the analytical sample, %.

The ash content of peat in working condition (A r) is calculated by the formula:

A r \u003d A d? (100 + Wr)/100, % (11.9)

where W r – mass fraction total moisture in working condition according to the test sample, %.

The final result of the test is taken as the average arithmetic value two parallel definitions within the allowed discrepancies.

Permissible discrepancies between the results of two parallel determinations should not exceed the values ​​indicated in Table 11.1.

Table 11.1 - Discrepancy between the results of determining the ash content of peat and products of its processing

Features of the composition and properties of marsh peat soils are determined by indicators of the composition and properties of peat horizons. The composition of gley horizons is diverse and largely depends on the granulometric, mineralogical, and chemical compositions of rocks and soils on which peat soils were formed. Their common features are unfavorable physical properties (disaggregation and density) and the presence of ferrous forms of iron.

Genetic and agronomic assessment of peat soils is carried out according to the thickness of the peat layer and the following indicators of peat: degree of decomposition, botanical composition, composition of organic matter, nitrogen content, ash content and composition of ash elements, reaction and physical properties.

organic matter

organic matter. It makes up the bulk (on average 85-95%) of peat. In upland bog soils, it is represented mainly by cellulose, hemicellulose, lignin, and wax resins. The peat of these soils is poorly humified; humic substances make up 10-15% of the total carbon; FAs predominate in their composition.

Peat of lowland bog soils is well humified, it contains up to 40-50% of humic substances, in which humic acids predominate.

Peat of bog soils is rich in nitrogen (from 0.5-2.0% in upland and up to 3-4% in low-lying soils), but it is contained in forms that are difficult to mobilize. In the peat of raised bog soils, nitrogen is present in various nitrogen-containing compounds of the initial plant residues, in the peat of lowland soils - in a significant part and nitrogen of humic substances. In terms of reserves and forms of nitrogen compounds, lowland bog soils are more valuable than upland soils as an object of development and use of peat for the preparation of fertilizers.

Soil response and cation uptake capacity

The reaction of peat in raised bog soils is acidic, while in lowland soils it varies from slightly acidic to slightly alkaline (in lowland calcareous soils). Only sulfate lowland peat soils are extremely acidic (pH KCL 1.1-3.0).

All types of peat have a high cation absorption capacity (from 80-90 to 130-200 mg * equiv), but differ in hydrolytic acidity and saturation with bases. In upland soils V = 10-30%, and in lowland soils - 70-100% .

Degree of decomposition

Degree of decomposition - an important characteristic of peat - determined by the relative content (in% ) decay products of tissues that have lost their cellular structure. It is established by special analyzes of peat, by studying the structure of plant residues under a microscope. In the field, the degree of decomposition can be determined by eye

(Table 2). The higher the degree of decomposition of peat, the more valuable are the agronomic qualities of peat soils as an object of possible agricultural development.

The peat of raised bog soils has a weak or medium degree of decomposition, while that of lowland soils is most often high.

Table 2 - Signs of different degrees of peat decomposition

Degree of decomposition	The main signs of the state of peat
	Peat type
	undecayed	The peat mass is not pressed through between the fingers. The surface of the compressed peat is rough with plant remains, which are clearly visible. Water is squeezed out by a stream, as from a sponge, transparent, light.
	Very slightly decomposed	Water is squeezed out in frequent drops, almost forming a jet, slightly yellowish.
	slightly decomposed	Water is squeezed out in large quantities, yellow in color, plant residues are less noticeable.
	medium decomposed	The mass of peat is almost not pressed through in the hand, plant residues are noticeable, water is squeezed out with frequent drops of light brown color, peat begins to slightly stain the hand.
	well decomposed	The mass of peat is pressed through weakly. Water is emitted by rare drops of brown color.
	badly decomposed	A mass of color is squeezed between the fingers, staining the hand. Only a few plant remains are visible in the peat. Water survives in small quantities, dark brown.
	Very badly decomposed	Peat is squeezed between the fingers in the form of a mud-like black mass. Water is not squeezed out. Plant remains are completely indistinguishable.

Ash content of peat

The ash content of peat is of great agronomic importance, since the ash contains ash nutrients (P, K, Ca, Mg, etc.). At the same time, the increased content of iron oxides, water-soluble salts in the composition of peat ash sharply reduces its quality. The ash content of peat in raised bog soils is the lowest (2-5%), low-lying soils range from 5-10% in depleted (transitional) to 30-50% in high-ash ones.

In upland bog soils, the composition and content of ash elements are determined by the ash content of the initial plant residues, while in lowland soils it largely depends on the hydrogenous accumulation of substances and the degree of peat silting.

The most important components of ash are phosphorus, potassium, and calcium. Phosphorus in peat is contained mainly in organic form and in small amounts (0.1-0.4%), with the exception of some grassy and alder bogs, in whose peat phosphorus can accumulate in the form of vivianite up to 2-8% per dry matter peat.

All types of peat are poor in potassium. The content of calcium in the peat of raised bogs is small, and in the peat of lowland soils - an average of 2-4% , reaching 30% and more in carbonate genera.

Peat of certain types contains a significant amount of iron (5-20% or more in terms of Fe 2 O 3); saline peat soils contain up to 2% of water-soluble salts.

Peat horizons

Peat horizons of bog soils have specific physical properties: low density, high moisture capacity, low

water permeability and thermal conductivity. Moisture capacity of lowland peat ranges from 400 to 900% , riding - from 1000 to 1200%.

The amount of ash elements in the deposits of the forest-steppe depends mainly on the location of the peat bog in the relief, which determines the type of its water supply and the possibility of bringing alluvial and deluvial products, which greatly increase the ash content of peat. It is natural, therefore, that the lowest ash content is characteristic of peat bogs of the watershed group, and the highest - of floodplain peat bogs. Peatlands of the terraced group occupy an intermediate position between watershed and floodplain peatlands.

But even within each topological group of peatlands, very significant fluctuations in ash content are often observed, depending on the influence of various factors. Thus, the deposit of hypnum and sphagnum peatlands of the watershed group in the southern steppe regions contains ash from 6 to 14%.

In the forest belt, the ash content of peat is lower, namely, for sphagnum deposits it ranges from 2 to 10%, for grass and forest deposits - from 7 to 16%.

The ash content of peat in terraced deposits is, as a rule, somewhat higher than in watershed deposits, which depends on the possibility of falling products of deluvial washout. So, in the sphagnum peat bog "Lebyazhye" the ash content ranges from 3.8 to 16.6%, in the sedge peat bog "Voznesenskoye" - from 6.6 to 26.0% and in the forest (in the 47th quarter of the Serpovsky forestry) - from 17 .6 to 25.6%.

As for the peatlands of the floodplain group, here the fluctuations in ash content reach very wide limits not only in different peatlands, but even in separate areas of the same peatland. In general, the peatlands of the floodplain group have an increased ash content, due to mechanical clogging with alluvium and deluvium during the period of peat formation. Significant fluctuations in the ash content of peat in different peat bogs depend on the amount of alluvial material that fell into the peat bog, and fluctuations in ash in the same peat bog depend on the uneven distribution of sediment over its area and the accumulation of calcareous tuff and vivianite in places as a result of the activity of soil and ground waters. In floodplains, peat with an ash content of 6-8% is relatively rare; on the contrary, ash content of 15-30% and above is a common occurrence.

There is no clearly expressed pattern in the distribution of ash content along the profile, but in most cases it increases in the near-bottom, as well as in the uppermost horizon. This phenomenon is explained by a stronger clogging of these horizons with deluvial-alluvial sediments.

Significant fluctuations in ash content for different parts of the peat bog often make it impossible to judge the fuel or agricultural value of the entire peat bog from the average ash content. This makes it necessary to divide it into sections with different ash content, allowing the possibility of using peat in one direction or another. The high ash content almost completely obscures the significance of the botanical composition in the qualitative assessment of peat, causing significant changes in the calorific value and chemical composition of peat.

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Physical and chemical characteristics

Peat - organic fertilizer, is a plant mass decomposed in conditions of excessive moisture and lack of air. The composition of peat includes non-humified plant residues, humus, and mineral compounds.

Peat classification

According to the conditions of formation, peat is divided into three types:

Agrochemical assessment of peat is carried out according to the following properties:

Botanical composition

determines acidity, ash content, degree of humification, supply of nutrients.

The degree of decomposition of peat

. There are weakly decomposed (5-25% humified substances) and moderately decomposed peat (25-40%).

Ash content of peat

can be normal (up to 12% ash by dry weight) and high (more than 12%). High-ash, as a rule, are low-lying peats with an ash content of 20-30% or more. Increased ash content due to the content of calcium in the form of lime and phosphorus (vivianite) increases the value of peat. decreases during the transition from low-lying peat to high-moor peat.

• . Most of all, peat contains this element. Its main part is in organic form and becomes available to plants only after mineralization.
• . The content in peat is low. At the same time, two-thirds of it is soluble in weak acids and available to plants.
• . The content is very low, only less than half of it is in a state available to plants.
• . Of all the trace elements, peat contains the smallest amount.

Acidity of peat (

pH) is a very important indicator. The method of using peat depends on the level of acidity. With a pH of 5.5 or less, peat (even lowland) is not allowed to be used without prior composting with lime, phosphate rock, ash, manure, etc. Taking into account hydrolytic acidity, all types of peat are capable of being composted into digestible forms for plants.

Absorption capacity, absorption capacity (CEC)

- an indicator that is significant when using peat as bedding material in animal husbandry as a material that absorbs moisture (moisture capacity) and gases, usually ammonia.

Maximum moisture capacity is a hallmark of high-moor peats. The indicator gradually decreases with the transition to lowland types, but remains quite high.

Agrochemical indicators, % on absolutely dry mass of various types of peat, according to:
Peat type	ash	pH values		organic matter
									mg eq/100g dry weight
lowland
transition
riding

Application

Agriculture

Peat is widely used in agriculture. In animal husbandry, various types of peat are used for animal bedding. In crop production, peat is used as a component of various composts, in the preparation of peat pots and cubes, as a substrate for greenhouses, as a mulching material, as an independent fertilizer.

Fertilizer brands registered and approved for use in Russia, in the production of which peat is used, are placed in the table on the right.

Application methods

Peat as a fertilizer is applied on light soils in or.

As a mulching material, surface-ventilated lowland and transitional peat mosses are used.

The drained peatlands are used for crop cultivation. For these purposes, peat extraction is suitable after removing the upper layer of the peat bog with a thickness of the remaining peat layer of at least 50 cm. In this case, liming, the use of various and.

Industry

Peat is a combustible mineral, the predecessor of a number of coals, used as a fuel. (a photo)

Deep chemical processing of peat raw materials makes it possible to obtain humic acids, bitumen, methyl and ethanol, acetic and oxalic acids, furfural, dry ice, fodder yeast, peat coke, semi-coke, etc.

Behavior in soil

The introduction of pure peat into the soil is recognized as ineffective. Raw peat contains 80-90% water, and with one ton of it only 100-200 kg of dry matter is added.

Dry peat has a high absorption capacity, and its application leads to the absorption of moisture from the soil. Peat, even at a moisture content of 35-40%, causes the soil to dry out, which, in turn, leads to a slowdown in the decomposition of peat itself, since it does not decompose well in a dry arable layer.

Application on various types of soil

To increase the availability of nitrogen and other nutrients, peat is composted with biologically active components (slurry, feces). For composting, peat is used with a degree of decomposition of more than 20%; lime and ash are added to improve the nutritional qualities of the compost. (a photo)

Peat is used for the preparation of peat-ammonia fertilizers (TMAU) and various peat substrates for greenhouse vegetable growing.

Light soils

. It is allowed to use low-lying peat rich in lime (peat tuffs) or phosphorus (vivianite peat) as a fertilizer. Peat must meet the following agrochemical characteristics: pH - more than 5.5, ash content - more than 10% (including CaO content more than 4%), degree of decomposition - more than 40-50%. The efficiency of peat application increases with the simultaneous application of small doses of other organic fertilizers (slurry, semi-liquid manure, feces, bird droppings).

Impact on crops

Peat fertilizers and composts have a positive effect on all crops, increasing the quantitative and qualitative characteristics of productivity.

Receipt

Peat from natural deposits is obtained in various ways. The most modern - milling. The peat deposit is drained using a system of diversion channels, then it is cleared of tree and shrub vegetation and leveled. All peat extraction operations are performed by one specialized combine, the design of which provides for the strengthening of the suction nozzle on the front, and steel cutters on the back.

The cutters destroy the layers of peat, through the nozzles the loosened peat is sucked into the combine and transported to the body with the air flow. Along the way, the peat crumb dries up. From the body on the belt conveyor, it is stored along the edge of the field and subsequently delivered to peat processing plants. (a photo)