Organic and mineral fertilizers have a huge impact on the soil. In fact, such an agrotechnical function as soil fertilization is a more intense imitation of complex natural processes occurring in an ecosystem over long periods.

Man is changing the natural principles of interaction between plants, animals and soil, adapting technologies to the most effective results when growing crops.

The effect of fertilizers on the soil can be different - both positive and negative. In order not to harm the soil, plants and beneficial microorganisms, it is necessary to comply with agrotechnical and environmental standards developed for various agricultural types of fertilizers.

The most useful for the soil are natural fertilizers. First of all, it is freshwater silt. It can be applied in its pure form or diluted with compost, or mixed with other types of fertilizers.

Acidophilic crops prefer acidic soil. How can you change the pH of the soil to the acidic side? For this purpose, such a type of natural fertilizer as needles is well suited. The introduction of needles into the ground can give a good effect for acidophilic plants, but will negatively affect other species that require a neutral or alkaline soil environment to grow.

Many fruit trees (primarily apples and pears) need iron during the ripening period. Thus, the treatment of fruit trees with iron sulphate will help to provide them with iron, which will favorably affect the yield, size and bright color of the fruit.

Nitrogen fertilizers should be applied to the soil with care. The fact is that as a result of the accumulation of nitrate salts (nitrates) in the soil, many agricultural crops accumulate nitrates in themselves and become poisonous to humans and animals. This is especially true for melon crops.

The use of iodine fertilizers for top dressing outside the root system gives a good effect on vegetable crops and fruit and berry plants (adds up to 40% yield).

Some plants prefer alkaline soil. In addition, a situation often arises when plants and soil are significantly polluted by vehicle exhausts and other industrial waste.

This leads to the accumulation of heavy metals in the soil, which, with a high degree of probability, leads to diseases in humans and animals. Lime or ash can be used to neutralize heavy metals and change the pH of the soil to alkaline. Alkali binds heavy metals, turning them into salts.

There are other types of fertilizers that allow you to change the structure, acidity, fertility, salinity and other soil indicators. The main thing is that when using fertilizers, agrotechnical and environmental standards are not violated.

Kuban State University

Department of Biology

in the discipline "Soil Ecology"

"The hidden negative effect of fertilizers".

Performed

Afanasyeva L. Yu.

5th year student

(speciality -

"Bioecology")

Checked Bukareva O.V.

Krasnodar, 2010

Introduction…………………………………………………………………………………...3

1. The effect of mineral fertilizers on soils……………………………………...4

2. The effect of mineral fertilizers on atmospheric air and water…………..5

3. The influence of mineral fertilizers on product quality and human health…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………

4. Geoecological consequences of the use of fertilizers……………………...8

5. The impact of fertilizers on the environment……………………………..10

Conclusion………………………………………………………………………………….17

List of used literature…………………………………………………...18

Introduction

Pollution of soils with foreign chemicals causes great damage to them. A significant factor in environmental pollution is the chemicalization of agriculture. Even mineral fertilizers, if used incorrectly, can cause environmental damage with a dubious economic effect.

Numerous studies of agricultural chemists have shown that different types and forms of mineral fertilizers affect soil properties in different ways. Fertilizers introduced into the soil enter into complex interactions with it. All sorts of transformations take place here, which depend on a number of factors: the properties of fertilizers and soil, weather conditions, and agricultural technology. From how the transformation of certain types of mineral fertilizers (phosphorus, potash, nitrogen) occurs, their influence on soil fertility depends.

Mineral fertilizers are an inevitable consequence of intensive farming. There are calculations that in order to achieve the desired effect from the use of mineral fertilizers, their world consumption should be about 90 kg / year per person. The total production of fertilizers in this case reaches 450-500 million tons/year, while at present their world production is 200-220 million tons/year or 35-40 kg/year per person.

The use of fertilizers can be considered as one of the manifestations of the law of increasing energy input per unit of agricultural output. This means that in order to obtain the same increase in yield, an increasing amount of mineral fertilizers is required. So, at the initial stages of fertilizer application, an increase of 1 ton of grain per 1 ha ensures the introduction of 180-200 kg of nitrogen fertilizers. The next additional ton of grain is associated with a dose of fertilizer 2-3 times greater.

Environmental consequences of the use of mineral fertilizers It is advisable to consider, at least from three points of view:

Local impact of fertilizers on ecosystems and soils to which they are applied.

Outrageous impact on other ecosystems and their links, primarily on the aquatic environment and atmosphere.

Impact on the quality of products obtained from fertilized soils and human health.

1. Effect of mineral fertilizers on soils

In the soil as a system, such changes that lead to loss of fertility:

Increases acidity;

The species composition of soil organisms is changing;

The circulation of substances is disrupted;

The structure that worsens other properties is destroyed.

There is evidence (Mineev, 1964) that an increased leaching of calcium and magnesium from them is a consequence of an increase in soil acidity with the use of fertilizers (primarily acidic nitrogen fertilizers). To neutralize this phenomenon, these elements have to be introduced into the soil.

Phosphorus fertilizers do not have such a pronounced acidifying effect as nitrogen fertilizers, but they can cause zinc starvation of plants and the accumulation of strontium in the resulting products.

Many fertilizers contain foreign impurities. In particular, their introduction can increase the radioactive background and lead to progressive accumulation of heavy metals. Basic way reduce these effects.– moderate and scientifically based use of fertilizers:

Optimal doses;

The minimum amount of harmful impurities;

Alternate with organic fertilizers.

You should also remember the expression that "mineral fertilizers are a means of masking realities." Thus, there is evidence that more minerals are removed with the products of soil erosion than they are applied with fertilizers.

2. Effect of mineral fertilizers on atmospheric air and water

The influence of mineral fertilizers on atmospheric air and water is mainly associated with their nitrogen forms. Nitrogen from mineral fertilizers enters the air either in free form (as a result of denitrification) or in the form of volatile compounds (for example, in the form of nitrous oxide N 2 O).

According to modern concepts, gaseous losses of nitrogen from nitrogen fertilizers range from 10 to 50% of its application. An effective means of reducing gaseous losses of nitrogen is their scientifically substantiated application:

Application to the root-forming zone for the fastest absorption by plants;

The use of substances-inhibitors of gaseous losses (nitropyrin).

The most tangible impact on water sources, in addition to nitrogen, is phosphorus fertilizers. Carryover of fertilizers into water sources is minimized when applied correctly. In particular, it is unacceptable to spread fertilizers on the snow cover, disperse them from aircraft near water bodies, and store them in the open.

3. Influence of mineral fertilizers on product quality and human health

Mineral fertilizers can have a negative impact both on plants and on the quality of plant products, as well as on the organisms that consume them. The main of these impacts are presented in tables 1, 2.

At high doses of nitrogen fertilizers, the risk of plant diseases increases. There is an excessive accumulation of green mass, and the probability of plant lodging increases sharply.

Many fertilizers, especially chlorine-containing ones (ammonium chloride, potassium chloride), have a negative effect on animals and humans, mainly through water, where released chlorine enters.

The negative effect of phosphate fertilizers is mainly due to the fluorine, heavy metals and radioactive elements contained in them. Fluorine at its concentration in water more than 2 mg/l can contribute to the destruction of tooth enamel.

Table 1 - The impact of mineral fertilizers on plants and the quality of plant products

Types of fertilizers	The influence of mineral fertilizers
	positive	negative
	Increase the protein content in the grain; improve the baking quality of grain.	At high doses or untimely methods of application - accumulation in the form of nitrates, violent growth to the detriment of stability, increased morbidity, especially fungal diseases. Ammonium chloride contributes to the accumulation of Cl. The main accumulators of nitrates are vegetables, corn, oats, and tobacco.
Phosphoric	Reduce the negative effects of nitrogen; improve product quality; help to increase the resistance of plants to diseases.	At high doses, toxicosis of plants is possible. They act mainly through the heavy metals contained in them (cadmium, arsenic, selenium), radioactive elements and fluorine. The main accumulators are parsley, onion, sorrel.
Potash	Similar to phosphorus.	They act mainly through the accumulation of chlorine when making potassium chloride. With an excess of potassium - toxicosis. The main accumulators of potassium are potatoes, grapes, buckwheat, greenhouse vegetables.

Table 2 - The impact of mineral fertilizers on animals and humans

Types of fertilizers	Main Impacts
Nitrogen - nitrate forms	Nitrates (maximum concentration limit for water 10 mg/l, for food - 500 mg/day per person) are reduced in the body to nitrites, which cause metabolic disorders, poisoning, deterioration of the immunological status, methemoglobinia (oxygen starvation of tissues). When interacting with amines (in the stomach), they form nitrosamines - the most dangerous carcinogens. In children, they can cause tachycardia, cyanosis, loss of eyelashes, rupture of the alveoli. In animal husbandry: beriberi, reduced productivity, accumulation of urea in milk, increased morbidity, reduced fertility.
Phosphoric - superphosphate	They act mainly through fluorine. Its excess in drinking water (more than 2 mg / l) causes damage to the enamel of teeth in humans, loss of elasticity of blood vessels. At a content of more than 8 mg / l - osteochondrosis phenomena.
Chlorine-containing fertilizers - potassium chloride - ammonium chloride	Consumption of water with a chlorine content of more than 50 mg/l causes poisoning (toxicosis) in humans and animals.

Influence of mineral fertilizers on soil microorganisms and its fertility. The introduction of fertilizers into the soil not only improves plant nutrition, but also changes the conditions for the existence of soil microorganisms, which also need mineral elements.

Under favorable climatic conditions, the number of microorganisms and their activity after the introduction of fertilizers into the soil increase significantly. The decomposition of humus intensifies, the mobilization of nitrogen, phosphorus and other elements increases.

After the application of mineral fertilizers, the activity of bacteria is activated. In the presence of mineral nitrogen, humus is more easily decomposed and used by microorganisms. The application of mineral fertilizers causes a slight decrease in the number of actinomycetes and an increase in the fungal population, which may be a consequence of a shift in the reaction of the environment to the acid side as a result of the introduction of physiologically acidic salts: actinomycetes do not tolerate acidification well, and the reproduction of many fungi accelerates in a more acidic environment.

Mineral fertilizers, although they activate the activity of microorganisms, reduce the loss of humus and stabilize the level of humus, depending on the amount of crop and root residues left.

The introduction of mineral and organic fertilizers into the soil increases the intensity of microbiological processes, resulting in a conjugated increase in the transformation of organic and mineral substances.

A characteristic indicator of the activation of microbial activity under the influence of fertilizers is the increased "respiration" of the soil, i.e., the release of CO 2 by it. This is the result of accelerated decomposition of soil organic compounds, including humus.

The introduction of phosphorus-potassium fertilizers into the soil contributes little to the use of soil nitrogen by plants, but enhances the activity of nitrogen-fixing microorganisms.

Sometimes the introduction of mineral fertilizers into the soil, especially in high doses, adversely affects its fertility. This is usually observed on low-buffer soils when using physiologically acidic fertilizers. When the soil is acidified, aluminum compounds that are toxic to soil microorganisms and plants pass into the solution.

The introduction of lime, especially together with manure, has a beneficial effect on the saprotrophic microflora. By changing the pH of the soil in a favorable direction, lime neutralizes the harmful effects of physiologically acidic mineral fertilizers.

The influence of mineral fertilizers on the yield is associated with the zonal position of soils. As already noted, in the soils of the northern zone, microbiological mobilization processes proceed slowly. Therefore, in the north, there is a stronger shortage of basic nutrients for plants, and mineral fertilizers, even in small doses, are more effective than in the southern zone. This does not contradict the well-known thesis about the best effect of mineral fertilizers against the background of high soil cultivation.

http://biofile.ru/bio/4234.html

The increase in the mobility of some microelements contained in the soil should also be attributed to the negative consequences of the use of fertilizers. They are more actively involved in geochemical migration. This leads to a deficit of B, Zn, Cu, Mn in the arable layer. The limited supply of microelements to plants adversely affects the processes of photosynthesis and the movement of assimilates, reduces their resistance to diseases, insufficient and excessive moisture, high and low temperatures. The main cause of disturbances in the metabolism of plants with a lack of trace elements is a decrease in the activity of enzyme systems.

The lack of trace elements in the soil forces the use of microfertilizers. So, in the USA, their use in the period from 1969 to 1979. increased from 34.8 to 65.4 thousand tons of active ingredient.

Due to the profound changes in the agrochemical properties of soils resulting from the use of fertilizers, it became necessary to study their effect on the physical characteristics of the arable layer. The main indicators of the physical properties of the soil are the aggregate composition and water resistance of soil particles. An analysis of the results of a limited number of studies conducted to study the effect of mineral fertilizers on the physical properties of the soil does not allow us to draw definite conclusions. In some experiments, a deterioration in physical properties was observed. When re-cultivating potatoes, the proportion of soil aggregates larger than 1 mm in the variant with the introduction of nitrogen, phosphorus and potassium, compared with the unfertilized plot, decreased from 82 to 77%. In other studies, when a complete mineral fertilizer was applied for five years, the content of agronomically valuable aggregates in the chernozem decreased from 70 to 60%, and water-stable - from 49 to 36%.

Most often, the negative effect of mineral fertilizers on the agrophysical properties of the soil is found when studying its microstructure.

Micromorphological studies have shown that even small doses of mineral fertilizers (30-45 kg/ha) have a negative effect on the soil microstructure, which persists for 1-2 years after their application. The packing density of microaggregates increases, the visible porosity decreases, and the proportion of granular aggregates decreases. Continuous application of mineral fertilizers leads to a decrease in the proportion of particles of spongy microstructure and to an increase of 11% in non-aggregated material. One of the reasons for the deterioration of the structure is the depletion of the arable layer with excrement of soil animals.

Probably, the agrochemical and agrophysical properties of soils are closely related, and therefore increasing acidity, depletion of the arable horizon in bases, a decrease in humus content, and deterioration in biological properties should naturally be accompanied by a deterioration in agrophysical properties.

In order to prevent the negative impact of mineral fertilizers on soil properties, liming should be carried out periodically. By 1966, the annual liming area in the former USSR exceeded 8 million hectares, and the volume of lime applied amounted to 45.5 million tons. However, this did not compensate for the loss of calcium and magnesium. Therefore, the proportion of lands subject to liming in a number of regions did not decrease, but even slightly increased. In order to prevent an increase in the area of ​​acidic lands, it was planned to double the supply of lime fertilizers to agriculture and bring them up to 100 million tons by 1990.

Liming, lowering the acidity of the soil, simultaneously causes an increase in gaseous losses of nitrogen. When carrying out this technique, they increase by 1.5-2 times. Such a reaction of soils to the introduction of ameliorants is the result of changes in the direction of microbiological processes, which can cause disruption of geochemical cycles. In this regard, doubts were expressed about the advisability of using liming. In addition, liming exacerbates another problem - soil pollution with toxic elements.

Mineral fertilizers are the main source of soil pollution with heavy metals (HM) and toxic elements. This is due to the content of strontium, uranium, zinc, lead, vanadium, cadmium, lanthanides and other chemical elements in the raw materials used for the production of mineral fertilizers. Their complete extraction is either not envisaged at all, or is complicated by technological factors. The possible content of accompanying elements in superphosphates and other types of mineral fertilizers widely used in modern agriculture is given in tables 1 and 2.

In large quantities, pollutant elements are found in lime. Its application in the amount of 5 t/ha can change the natural levels of cadmium in the soil by 8.9% of the total content.

Table 1. Content of impurities in superphosphates, mg/kg

When mineral fertilizers are applied at a dose of 109 kg/ha of NPK, approximately 7.87 g of copper, 10.25 g of zinc, 0.21 g of cadmium, 3.36 g of lead, 4.22 g of nickel, 4.77 g of chromium enter the soil . According to TsINAO data, for the entire period of using phosphate fertilizers, 3200 tons of cadmium, 16633 tons of lead, 553 tons of mercury were introduced into the soils of the former USSR. Most of the chemical elements that have entered the soil are in a weakly mobile state. The half-life of cadmium is 110 years, zinc - 510, copper - 1500, lead - several thousand years.

Table 2. Content of heavy metals in fertilizers and lime, mg/kg

Soil contamination with heavy and toxic metals leads to their accumulation in plants. For example, in Sweden, the concentration of cadmium in wheat has doubled over the current century. In the same place, when using superphosphate in a total dose of 1680 kg/ha, introduced in parts over 5 years, an increase in the content of cadmium in wheat grain by 3.5 times was observed. According to some authors, soil contamination with strontium resulted in a threefold increase in its content in potato tubers. Russia has not yet paid sufficient attention to the contamination of crop products with chemical elements.

The use of contaminated plants as food or feed is the cause of various diseases in humans and farm animals. The most dangerous heavy metals include mercury, lead and cadmium. The ingestion of lead into the human body leads to sleep disturbances, general weakness, mood deterioration, memory impairment and a decrease in resistance to bacterial infections. The accumulation of cadmium in food, the toxicity of which is 10 times higher than lead, causes the destruction of red blood cells, disruption of the kidneys, intestines, softening of bone tissue. Pair and triple combinations of heavy metals increase their toxic effect.

The WHO Expert Committee has developed standards for the intake of heavy metals into the human body. It is envisaged that every week a healthy person weighing 70 kg can receive with food, without harm to their health, no more than 3.5 mg of lead, 0.625 mg of cadmium and 0.35 mg of mercury.

In connection with the increase in food contamination, standards for the content of HMs and a number of chemical elements in crop products were adopted (Table 3).

Table 3. Maximum permissible concentrations of chemical elements, mg/kg of raw product

Element	Bread products and grains	Vegetables	Fruit	Milk products
Mercury	0,01	0,02	0,01	0,005
Cadmium	0,02	0,03	0,03	0,01
Lead	0,2	0,5	0,4	0,05
Arsenic	0,2	0,2	0,2	0,05
Copper				0,5
Zinc				5,0
Iron				3,0
Tin	-			100,0
Antimony	0,1	0,3	0,3	0,05
Nickel	0,5	0,5	0,5	0,1
Selenium	0,5	0,5	0,5	0,5
Chromium	0,2	0,2	0,1	0,1
Aluminum				1,0
Fluorine	2,5	2,5	2,5	2,5
Iodine				0,3

Contamination of crop products with HMs and chemical elements is dangerous for humans not only when it is used directly, but also when used for fodder purposes. For example, feeding cows plants grown on polluted soils has led to an increase in the concentration of cadmium in milk up to 17-30 mg/l, while the acceptable level is 0.01 mg/l.

To prevent the accumulation of chemical elements in milk, meat, to exclude the possibility of their negative impact on the condition of farm animals, in many countries the maximum permissible concentrations (MPC) for chemical elements contained in fodder plants are adopted. According to EEC standards, the safe lead content in forage is 10 mg/kg of dry matter. In the Netherlands, the allowable level of cadmium in green fodder is 0.1 mg/kg dry weight.

The background content of chemical elements in soils is shown in Table 4. With the accumulation of HMs in the soil and their subsequent entry into plants, they are concentrated mainly in the vegetative organs, which is explained by the protective reaction of plants. An exception is cadmium, which easily penetrates both leaves and stems and generative parts. For a correct assessment of the degree of accumulation of various elements in plants, it is necessary to know their usual content when growing crops on uncontaminated soils. Information on this issue is rather contradictory. This is due to the large differences in the chemical composition of soils. The background content of lead in soils is approximately 30, and cadmium - 0.5 mg/kg. The concentration of lead in plants grown on clean soils is 0.009-0.045, and cadmium is 0.011-0.67 mg/kg of wet matter.

Table 4. Content of some elements in arable soils, mg/kg

Element	Regular content	MPC	Element	Regular content	MPC
As	0,1-20		Ni	2-50
V	5-20		Pb	0,1-20
Be	0,1-5		Sb	0,01-0,5
Vg	1-10		Se	0,01-5
CD	0,01-1		sn	1-20
So	1-10		Tl	0,01-0,5
SG	2-50		Ti	10-5000
Cu	1-20		U	0,01-1
F	50-200		V	10-100
Ga	0,1-10		Zn	3-50
hg	0,01-1		Mo	0,2-5

The establishment of strict standards for plant contamination is explained by the fact that when they are grown on contaminated soils, the content of individual elements can increase tenfold. At the same time, some chemical elements become toxic with a three- or even two-fold increase in their concentration. For example, copper content in plants is typically about 5-10 mg/kg on a dry weight basis. At a concentration of 20 mg/kg, the plants become toxic to sheep, and at 15 mg/kg, to lambs.

Chapter 2 http://selo-delo.ru/8-zemelnie-resursi?start=16

Due to the decrease in the use of mineral fertilizers, the importance of organic fertilizers as a source of nutrients has increased. They are the most complete in terms of the content of nutrients needed by plants. 1 ton of bedding manure contains 5 kg N, 2.5 kg P 2 O 5 , 6 kg K 2 O; 3 - 5 g B, 25 g Zn; 3.9 g Cu, 0.5 Mo and 50 g Mn. It should be borne in mind that the cost of 1 kg of nutrients applied with solid manure is 24-37% lower than in an equivalent amount of mineral fertilizers. Organic fertilizers play an important role in increasing soil fertility and crop yields.

The introduction of organic fertilizers has a positive effect on the balance of humus in the soil, improves the air and water regime of the soil, and enhances the microbiological activity of the soil. From 1 ton of organic fertilizers on loamy soils, 50 kg / ha of humus is formed, on sandy soils - 40 and sandy - 35.

Currently, about 15 t/ha of organic fertilizers are applied per 1 ha of arable land in the world. Approximately 14 t/ha is used in the USA, 25 t/ha in England, and 70 t/ha in the Netherlands. In Belarus, the use of organic fertilizers in 1991 reached 83 million tons, or 14.5 tons/ha.

In recent years, in the Republic of Belarus, due to a systematic reduction in the number of livestock and a sharp reduction in the volume of peat harvesting, the use of organic fertilizers has significantly decreased, which led to a decrease in the rate of accumulation of humus, and in some areas there was a decrease in the humus content. In 1995, the use of organic fertilizers in the republic decreased to 9.5, and in 1999 to 8.2 t/ha.

One of the measures that can reduce the use of organic fertilizers is the substantiation of the optimal size of perennial grass crops and increasing their yield. At present, 3 hectares of perennial grasses fall on 1 ha of tilled crops. Even with a decrease in the use of organic fertilizers in recent years, due to an increase in the share of plant residues in the total volume of organic matter entering the soil from 46 to 55%, it was possible, in general, to maintain the achieved level of humus content in the soil on arable soils. To maintain a deficit-free balance of humus in the republic, it is necessary to ensure the use of organic fertilizers at the level of 50 million t/ha, or 9-10 t/ha. It is assumed that due to the increase in the number of livestock, the introduction of organic fertilizers may increase to 52.8 million tons. The republic's demand for peat is about 3 million tons.

With proper application, the payback of 1 ton of organic fertilizers is: for cereals - 20 kg, potatoes - 90, fodder root crops - 200, corn (green mass) - 150 kg.

The following types of organic fertilizers are used in agriculture:

1. Organic fertilizers based on animal and poultry waste:

a) bedding manure;

b) bedless manure;

c) slurry;

d) bird droppings;

2. Fertilizers from natural organic raw materials:

b) composts;

3. Green manure and use of crop by-products:

a) straw

b) green manure;

4. Organic fertilizers based on municipal and industrial waste:

a) industrial and domestic waste;

b) sewage sludge;

c) hydrolytic lignin.

bedding manure- a mixture of liquid and solid animal excrement with bedding. Liquid animal excrement refers to potassium-nitrogen fertilizer, and solid - to nitrogen-phosphorus (Table 5.1).

The quality of manure, its chemical composition depend on: 1) the type of feeding; for example, when concentrated in the diet, manure contains more nutrients than when fed with roughage; 2) animal species (Table 5.2); 3) quantity and type of litter; 4) storage method (Table 5.3; 5.4)

Various bedding materials contain the following amounts of nutrients:

With a loose or hot storage method, when the manure is not compacted, aerobic conditions are created, thermophilic bacteria develop, the temperature inside the pile reaches 50 - 60 0 C. There is a rapid decomposition of organic matter, nitrogen volatilizes in the form of NH 3 , there are losses Р 2 O 5 and K 2 A. Losses of nitrogen during loose storage - about 30%.

T a b l e 5.1. The content of dry matter, nitrogen and ash elements in animal excrement, % http://www.derev-grad.ru/himicheskaya-zaschita-rastenii/udobreniya.html

With hot-pressed, or loose-dense, storage method (Krantz method), manure of loose laying after heating to 50 - 60 0 C is compacted. First, aerobic conditions are created, then anaerobic ones. Nitrogen and organic matter losses are reduced.

There is also a cold, or dense, storage method when anaerobic conditions are created. The manure in the heaps is immediately compacted. This is the best storage method in terms of nutrient retention. In this case, a constant temperature is maintained in the piles (15 - 35 0 WITH). Nitrogen losses are small, since the manure is always in a dense and wet state. Air access to such manure is limited, and water-free pores are occupied by carbon dioxide, which slows down microbiological activity.

Depending on the degree of decomposition, manure on a straw bed is divided into fresh, semi-rotted and humus.

In fresh slightly decomposed manure, straw slightly changes color and strength. When semi-ripened, it acquires a dark brown color, becomes less durable and breaks easily. At this stage of decomposition, manure loses 10 - 30% of its original mass and the same amount of organic matter. It is unprofitable to bring manure to the stage of humus, since in this case about 35% of organic matter is lost.

Weakly decomposed manure in the first year may have a weak effect, and in the aftereffect in the second and third years there may be relatively high yield increases. If there is a different degree of manure decomposition on the farm, more decomposed manure in areas of sufficient moisture can be applied in spring for tilled crops, and less decomposed manure in the summer after harvesting annual grasses for winter crops.

T a b l e 5.2. Chemical composition of fresh manure, %

	Manure on a straw bed	Manure on peat bed
Components	cattle	horse	sheep	pork	cattle	horse
Water	77,3	71,3	64,4	72,4	77,5	67,0
Organ. substance	20,3	25,4	31,8	25,0	-	-
Nitrogen: total	0,45	0,58	0,83	0,45	0,60	0,80
ammoniacal	0,14	0,19	-	0,20	0,18	0,28
Phosphorus	0,23	0,28	0,23	0,19	0,22	0,25
Potassium	0,50	0,63	0,67	0,60	0,48	0,53

It is irrational to introduce bedding manure into the soil in a fresh form, since mobile forms of nitrogen can be mobilized by microorganisms, and plants at the beginning of the growing season will not receive it in sufficient quantities. In addition, fresh manure contains weed seeds. Therefore, matured, semi-rotted manure should be used on farms. When harvesting organic fertilizers in the winter period, it is necessary to extend the terms of their composting and storage, and the application should be made in the summer-autumn period. This will allow you to get high-quality manure, free from weeds and pathogenic microflora.

Table 5.3. Effect of bedding manure storage methods on losses of organic matter and nitrogen, %

T a b l e 5.4. The content of nutrients in manure on straw bedding depending on the degree of its decomposition, %

To obtain good quality manure, it is stored in manure stores or in field piles.

Manure storages. When laying stacks, they strive to ensure that manure of varying degrees of decomposition is not mixed, but is located in separate parts of the manure storage. Laying manure in piles 2 - 3 m wide begins along the side of the store, which is adjacent to the slurry collector. The manure is laid in small sections, compacting each meter layer of manure, and then brought to full height (1.5 - 2 m). After the first stack is completely laid, along it, as manure arrives, the second stack is laid in the same way, then the third, etc. until the manure storage is full. Stacks should be tightly adjacent to each other. With this order of laying, on one side of the manure storage there will be more decomposed manure, and on the other - less decomposed, which will allow the use of manure of the desired quality.

3) Chapter 4 Application of organo-mineral complexes to improve soil fertility

Organomineralnye fertilizers http://biohim-bel.com/organomineralnye-udobreniya

The soil cannot be permanently fertile if it is not fertilized. Various substances, usually mineral or organic, are used to improve soil properties. These species differ from each other in nutrient saturation. Each of these types has its own advantages and disadvantages. So, for example, organic fertilizers do not always contain the full range of substances necessary to ensure the most comfortable conditions for the plant. In this case, organic fertilizers are supplemented with mineral ones. An example is humus or ash, which contain very little nitrogen. To make the soil more fertile, these agents are used in combination with mineral nitrogen agents. In addition, the use of untested organic fertilizers can contribute to the infection of the plant with some kind of infection.

organic fertilizers are substances of plant and animal origin introduced into the soil in order to improve the agrochemical properties of the soil and increase productivity. Various types of manure, bird droppings, composts, green manure are used as organic fertilizers. Organic fertilizers have a versatile effect on agronomic properties:

• in their composition, all the nutrients necessary for plants enter the soil. Each ton of dry matter of cattle manure contains about 20 kg of nitrogen, 10 - phosphorus, 24 - potassium, 28 - calcium, 6 - magnesium, 4 kg of sulfur, 25 g of boron, 230 - manganese, 20 - copper, 100 - zinc, etc. d. - this fertilizer is called complete.
• unlike mineral fertilizers, organic fertilizers are less concentrated in terms of nutrient content,
• manure and other organic fertilizers serve as a source of CO2 for plants. When 30–40 tons of manure is applied to the soil per day during the period of intensive decomposition, 100–200 kg/ha of CO2 is released per day.
• organic fertilizers are an energy material and food source for soil microorganisms.
• a significant part of the nutrients in organic fertilizers become available to plants only as they are mineralized. That is, organic fertilizers have an aftereffect, since elements from them are used for 3-4 years.
• manure efficiency depends on climatic conditions and decreases from north to south and from west to east.
• the introduction of organic fertilizers is quite expensive - there are high costs for transportation, application of fuels and lubricants, depreciation and maintenance.

bedding manure- components - solid and liquid animal excrement and bedding. The chemical composition largely depends on the litter, its type and quantity, the type of animals, the feed consumed, and the method of storage. Solid and liquid excretions of animals are unequal in composition and fertilizing qualities. Almost all phosphorus gets into solid secretions, in liquid it is very small. About 1/2 - 2/3 of the nitrogen and almost all of the potassium in the feed are excreted in the urine of animals. N and P of solid secretions become available to plants only after their mineralization, while potassium is in a mobile form. All nutrients of liquid secretions are presented in easily soluble or light mineral form.

bedding- when added to manure, it increases its yield, improves its quality and reduces the loss of nitrogen and slurry in it. Straw, peat, sawdust, etc. are used as bedding. During storage in manure, with the participation of microorganisms, the processes of decomposition of solid secretions with the formation of simpler ones occur. Liquid secretions contain urea CO(NH2)2, hypuric acid C6H5CONCH2COOH and uric acid C5H4NO3, which can decompose to free NH3, two forms N-protein and ammonia - no nitrates.

According to the degree of decomposition, fresh, semi-rotted, rotted and humus are distinguished.

Humus- black homogeneous mass rich in organic matter 25% of the original.

Application conditions - manure increases the yield for several years. In arid and extremely arid zones, the aftereffect exceeds the effect. The greatest effect of manure is achieved when it is applied under autumn plowing, with immediate incorporation into the soil. The introduction of manure in winter leads to significant losses of NO3 and NH4, and its efficiency decreases by 40–60%. Fertilizer rates in the crop rotation should be set taking into account the increase or maintenance of the humus content at the initial level. To do this, on chernozem soils, the saturation of 1 hectare of crop rotation should be 5-6 tons, on chestnut soils - 3-4 tons.

The dose of manure is 10 - 20 t / ha - arid, 20 - 40 t. - in insufficient moisture supply. The most responsive industrial crops are 25-40 t/ha. under winter wheat 20 - 25 t/ha under the predecessor.

Straw is an important source of organic fertilizers. The chemical composition of straw varies widely depending on soil and weather conditions. It contains about 15% H2O and approximately 85% consists of organic matter (cellulose, pengosans, hemocellulose and hygnin), which is a carbonaceous energy material for soil microorganisms, the basis of building material for the synthesis of humus. Straw contains 1-5% protein and only 3-7% ash. The composition of straw organic matter includes all the nutrients necessary for plants, which are mineralized by soil microorganisms into easily accessible forms. 1 g of straw contains on average 4-7 N, 1-1.4 P2O5, 12-18 K2O, 2-3 kg Ca , 0.8-1.2 kg Mg, 1-1.6 kg S, 5 g boron, 3 g Cu, 30 g Mn. 40 g Zn, 0.4 Mo, etc.

When evaluating straw as an organic fertilizer, not only the presence of certain substances, but also the C:N ratio is of great importance. It has been established that for its normal decomposition, the C:N ratio should be 20-30:1.

The positive effect of straw on soil fertility and agricultural yield. cultures is possible in the presence of the necessary conditions for its decomposition. The rate of decomposition depends on: the availability of food sources for microorganisms, their abundance, species composition, soil type, its cultivation, temperature, humidity, aeration.

slurry represents mainly the fermented urine of animals for 4 months from 10 tons of bedding manure with dense storage, 170 liters are released, with loose-dense storage - 450 liters and with loose storage - 1000 liters. On average, slurry contains N - 0.25 -0.3%, P2O5 - 0.03-0.06% and potassium - 0.4-0.5% - mainly nitrogen-potassium fertilizer. All the nutrients in it are in a form readily available to plants, so it is considered fast acting fertilizer. Utilization factor 60-70% for N and K.

bird droppings is a valuable fast-acting organic, concentrated fertilizer containing all the essential nutrients needed by plants. Thus, chicken manure contains 1.6% N, 1.5 P2O5, 0.8% K2O, 2.4 CaO, 0.7 MgO, 0.4 SO2. In addition to microelements, it contains microelements, Mn, Zn, Co, Cu. The amount of nutrients in poultry manure is highly dependent on the feeding conditions of the birds and the keeping of the birds.

There are two main ways to keep poultry: floor and cell. For floor maintenance, a deep, non-replaceable litter of peat, straw, and corn stalks is quite widely used. When poultry is caged, it is diluted with water, which reduces the concentration of nutrients and significantly increases the cost of using it as a fertilizer. Raw poultry manure is characterized by unfavorable physical properties that make mechanization of use difficult. It has a number of other negative properties: it spreads an unpleasant odor over long distances, contains a huge amount of weeds, a source of environmental pollution and a breeding ground for pathogenic microflora.

Green manure- fresh plant mass plowed into the soil to enrich it with organic matter and nitrogen. Often this technique is called green manure, and plants grown for fertilizer are green manure. Leguminous plants are cultivated as green manure in the southern Russian steppe - seradella, sweet clover, mung bean, sainfoin, rank, vetch, winter and wintering peas, winter vetch, fodder peas (pelyushka), astragalus; cabbage - winter and spring rapeseed, mustard, as well as their mixtures with legumes. As the proportion of the legume component in the mixture decreases, the supply of nitrogen decreases, which is compensated by a significantly larger amount of biological mass.

Green, like any organic fertilizer, has a multifaceted positive effect on the agrochemical properties of the soil and crop yields. Depending on the cultivation conditions, on each hectare of arable land, from 25 to 50 t / ha of green manure green mass is grown and plowed. The biological mass of green fertilizers contains a significantly smaller amount of nitrogen and especially phosphorus and potassium compared to manure.