How do fertilizers affect the soil. Abstract: Hidden negative fertilizer action. The effect of nitrogen fertilizers on plants
Putting into the fertilizer soil not only improves plant nutrition, but also changes the conditions for the existence of soil microorganisms, which also need mineral elements.
With favorable climatic conditions, the number of microorganisms and their activity after the fertilizer of the soil increase significantly. The decay of humus increases, and as a result, the mobilization of nitrogen, phosphorus and other elements increases.
There was a point of view that long-term use mineral fertilizer leads to a catastrophic loss of humus and deterioration physical properties Soil. However, experimental materials were not confirmed. Thus, on the turf-podzolic soil TSHA Academician D. N. Sprinknikov was laid with experience with different system Fertilizers. On the plots where mineral fertilizers were used, 36.9 kg of nitrogen were introduced on average, 43.6 kg R205 and 50.1 kg k2 o 1 hectares. In the soil, equipped with manure, it was made annually at 15.7 t / ha. After 60 years, a microbiological analysis of experimental defenses was carried out.
Thus, for 60 years in the soil, the content of humus decreased, but in fertilized soils, its losses were less than in the disobedient. This can be explained by the fact that the introduction of mineral fertilizers contributed to the development of authotrophic microflora (mostly algae), which led to some accumulation in the polar "soil of organic substances, and, consequently, humus. Manure is a direct source of humus formation, the accumulation of which under action This organic fertilizer is quite understandable.
On melts with the same fertilizer, but occupied by agricultural crops, fertilizers were even more favorable. Fine and root remnants here have activated the activities of microorganisms and compensated for the consumption of humus. Control soil in crop rotation contained 1.38% humus, obtained by NPK-1.46, and the cooked-1.96%.
It should be noted that in fertile soils that even obtained dung, the content of fulvocoslot decreases and relatively increasing - less movable fractions.
In general, mineral fertilizers to more or lesser extent stabilize the level of humus, depending on the number of reserved and root residues. This process of stabilization is rich in humus. If the manure is brought in large quantities, the content of humus in the soil increases.
The data of the Rotamsted Experimental Station (England), where long-term studies were conducted (about 120 years) with a winter wheat monoculture. In the soil that did not receive fertilizers, the content of humus decreased slightly.
With the annual introduction of 144 kg of mineral nitrogen with other mineral substances (P 2O 5, to 2O, etc.), a very small increase in the content of humus was noted. A very significant increase in the humusity of soil took place at the annual exposure to the soil 35 tons of manure per 1 hectare (Fig. 71).
Putting into the soil of mineral and organic fertilizers enhances the intensity of microbiological processes, as a result of which the transformation of organic and mineral substances is conjugate.
Experiments conducted by F. V. Turchin showed that the introduction of nitrogen-containing mineral fertilizers (labeled 15N) increases the crop of plants not only as a result of a helpful action, but also due to the best use of nitrogen plants from the soil (Table 27). In the experiment in each vessel, which accommodate 6 kg of soil, 420 mg of nitrogen were introduced.
With increasing dose nitrogen fertilizers The share of the soil nitrogen used increases.
The characteristic indicator of the activation of microflora activities under the influence of fertilizers is the strengthening of the "respiration" of the soil, that is, the allocation of CO2 it. This is the result of the accelerated decomposition of the organic compounds of the soil (including humus).
The introduction into the soil of phosphorus-potash fertilizers contributes to the use of soil nitrogen plants, but strengthens the activities of nitrogen-fixing microorganisms.
The above information makes it possible to conclude that, in addition to direct action on plants, nitrogenous mineral fertilizers have a large indirect influence - mobilize soil nitrogen
(Obtaining "extra nitrogen"). In humus-rich soils, such an indirect effect is much larger than direct. This affects the total efficiency of mineral fertilizers. The summarization of the results of 3,500 experiments with grain crops conducted in the non-sinnamine zone of the European part of the CIS, made by A. P. Fedoseyev, showed that the same fertilizer doses (NPK 50-100 kg / ha) are given on fertile soils significantly large crop gains than on the poor Soils: 4.1, respectively; 3.7 and 1.4 c / ha on high, medium - and weakly cultural soils.
It is very important that high doses of nitrogen fertilizers (about 100 kg / ha more) are effective only on high-cultural soils. On low-grade soils, they usually act negatively (Fig. 72).
Table 28 shows the generalized data of the scholars of the GDR on the flow rate of nitrogen to produce 1 C grain on different soils. As can be seen, more efficient mineral fertilizers are used on soils containing more humus.
Thus, to obtain high yields, it is necessary not only to fertilize the soil with mineral fertilizers, but also create a sufficient stock of nutrients for plants substances in the soil itself. This contributes to the grounding of organic fertilizers.
Sometimes making mineral fertilizers in the soil, especially in high doses, extremely adversely affects its fertility. This is usually observed on low-profile soils when using physiologically acidic fertilizers. When acidifying the soil into the solution, aluminum compounds are transferred to toxic effect on soil microorganisms and plants.
The adverse effect of mineral fertilizers was noted on the lungs of low-chicken sandy and sampling podzolic soils of the Solikamsky agricultural experimental station. One of the analyzes of a differently feudal soil of this station is given in Table 29.
In this experiment, N90, P90, K120, dung - 2 times in three years (25 t / ha) were introduced into the soil annually. At the rate of complete hydrolytic acidity was given to lime (4.8 t / ha).
Application for a number of years NPK significantly reduced the number of microorganisms in the soil. Only microscopic mushrooms were injured. Making lime, and especially lime with manure, has had a very beneficial effect on saprophistic microflora. By changing the reaction of the soil in a favorable side, the lime neutralized the harmful effects of physiologically acidic mineral fertilizers.
After 14 years of yields, when making mineral fertilizers, they actually decreased to zero as a result of strong soil acidification. The use of lime and manure contributed to the normalization of the pH of the soil and obtaining sufficiently high for the specified crop conditions. In general, the microflora of the soil and plants reacted to the change in the soil background approximately equally.
Generalization of a large material on the use of mineral fertilizers in the CIS (I. V. Tyurin, A. V. Sokolov et al.) Allows you to conclude that their influence on the crop is associated with the zonal position of soil. As noted, in the soils of the northern zone, microbiological mobilization processes flow slowly. Therefore, the deficiency for plants of the main batteries is stronger here, and mineral fertilizers act more efficiently than in the southern zone. This, however, does not contradict the above position on the best action of mineral fertilizers on high-cultural backgrounds in separate soil - climatic zones.
Briefly focus on the use of microferters. Some of them, for example, molybdenum, are included in the enzyme system of nitrogen-fixing microorganisms. For symbiotic azotfixation
a boron is also needed, which ensures the formation of a normal vascular system in plants, and therefore, the successful course of the nitrogenation process. Most other trace elements (Cu, Mn, Zn, etc.) in small doses enhances the intensity of microbiological processes in the soil.
As shown, organic fertilizers and especially manure have a very beneficial effect on the microflora of the soil. The mineralization rate of manure in the soil is determined by a number of factors, but at other favorable conditions It depends mainly on the relationship in the dung carbon to nitrogen (C: N). Usually, the manure causes an increase in harvest for 2-3 years in contrast to. Nitrogen fertilizers who do not have amersion. Semi-proverse manure with a narrower ratio of C: n shows a helpful effect since its insertion, since it does not have a carbon material that causes an energetic absorption of nitrogen by microorganisms. In the overwear, a significant part of nitrogen is translated into a migration form, which is weakly mineralized. Therefore, dung - a rash as nitrogen fertilizer has a smaller, but long-term action.
These features relate to both composts and other organic fertilizers. Taking into account, they can create organic fertilizers acting in certain phases of plant development.
Green fertilizers or sites are also widely used. These are organic fertilizers smelled into the soil, they are more or less mineralized depending on the soil - climatic conditions.
Recently great importance Pay on the use of straw as organic fertilizer. The depositing of straw could enrich the soil by Gumus. In addition, straw contains about 0.5% nitrogen and other elements necessary plants. With the decomposition of the straw, many carbon dioxide stands out, which is also beneficial on crops. Also in early XIX. in. English Chemist J. Devi pointed out the possibility of using straw as an organic fertilizer.
However, until recently, the straw is not recommended. This was justified by the fact that the straw has a wide relationship C: n (about 80: 1) and its sealing in the soil causes biological fixing of mineral nitrogen. Vegetable materials with a narrower ratio of C: n of such a phenomenon are not caused (Fig. 73).
Plants sowned after stabs are lacking nitrogen. The exception is only legumes, which provide themselves with nitrogen with the help of nitrogen bacteria that fix the molecular nitrogen of the culture, which provide themselves with nitrogen with the help of nodule bacteria fixing molecular nitrogen.
The lack of nitrogen after the sealing of the straw can be compensated for by the introduction of nitrogen fertilizers at the rate of 6-7 kg of nitrogen per 1t of smelled straw. In this case, the position is not fully corrected, since the straw contains some substances toxic to plants. A certain period of time is required for their detoxification, which is carried out by microorganisms that decompose these compounds.
Performed by last years Experimental work allows recommendations to eliminate the adverse effects of straw on agricultural crops.
Under the conditions of the northern zone, the straw in the form of cutting is advisable to steal into the upper layer of the soil. Here in aerobic conditions, all the toxic substances for plants are quite quickly decomposed. With a small pan, after 1-1.5 months, the destruction of harmful connections occurs and biologically fixed nitrogen begins to be released. In the south, especially in subtropical and tropical zones, the time break between the grinding of straw and sowing may be the most minimal even with its deep spare. Here all adverse moments disappear very quickly.
Subject to these recommendations, the soil is not only enriched with organic matter, but it is also activated by mobilization processes, including the activities of nitrogen-fixing microorganisms. Depending on a number of conditions, the introduction of 1 tons of straw leads to a fixation of 5-12 kg of molecular nitrogen.
Now, on the basis of numerous field experiments conducted in our country, it was quite confirmed by the expediency of using excess straw as an organic fertilizer.
The effect of soil processing and mineral fertilizer on the agrophysical properties of a typical black soil
G.N. Cherkasov, E.V. Dubovik, D.V. Dubovik, S.I. Kazantsev
Annotation. As a result of the research, the ambiguous effect of the method of main soil processing under winter wheat and corn and mineral fertilizers on the indicators of the agrophysical state of the chernozem is typical. The optimal density indicators, the structural state are obtained during a dummy plowing. It was revealed that the use of mineral fertilizers worsens the structural-aggregate state, but helps to increase the waterproofability of the soil separates with a dummy plowing relative to zero and surface treatment.
Keywords: structural and aggregate state, soil density, waterproofability, soil processing, mineral fertilizers.
Fertile soil along with sufficient nutrient content should have favorable physical conditions for the growth and development of crops. It has been established that the structure of the soil is the basis of favorable agrophysical properties.
Chernoined soils have a low degree of anthropotolation, which makes it possible to talk about the high degree of influence of anthropogenic factors, the main of which is the processing of the soil, as well as a number of other events that are used in cropping and contribute to the violation of a very valuable grainy structure, as a result of which it can spray Or, on the contrary, chuck out, which is permissible to certain limits in the soil.
Thus, the purpose of this work was to study the influence of the processing of soil, mineral fertilizers and the previous culture on the agricultural properties of the chernozem typical.
Studies were held in 2009-2010. Agrosil LLC (Kursk Region, Sudzhansky District), in the black soot of a typical heavy-chimney. Agrochemical characteristics of the site: RNC1- 5.3; The content of humus (in Tyurin) is 4.4%; Movable phosphorus (for chirik) - 10.9 mg / 100 g; exchange potassium (Chi-Rikov) - 9.5 mg / 100 g; Nitrogen alkali-hydrolyzed (by Cornefield) - 13.6 mg / 100. The cultivated cultures: the winter wheat of the Variety "August" and corn hybrid PR-2986.
The following methods of the main processing of the soil were studied in the experiment: 1) dummy plowing by 20-22 cm; 2) Surface treatment - 10-12 cm; 3) Zero treatment - direct sowing by the seedling John Dir. Mineral fertilizers: 1) without fertilizers; 2) under the winter wheat N2 ^ 52 ^ 2; Under the corn K14IER104K104.
The sampling was taken in the third decade of May, in a layer of 0-20 cm. The soil density was determined by the drilling method on N. A. Kacinsky. To study the structural-aggregate state, undisturbed soil samples weighing more than 1 kg were selected. For the allocation of structural individuals and aggregates, N. I. Savvinova was used to determine the structural-aggregate composition of the soil - dry and wet sifting.
Soil density is one of the main physical characteristics Soil. An increase in the density of the soil leads, as a rule, to a more dense packaging of soil particles, which in turn leads to a change in water, air and thermal regimes, what
subsequently, negatively affects the development of the root system of agricultural plants. At the same time, the requirements different plants To the density of the soil of unequal and depend on the type of soil, mechanical composition, cultivated culture. Thus, the optimal density of the soil for grain crops is 1.051.30 g / cm3, for corn - 1.00-1.25 g / cm3.
Studies have shown that under the influence of various soil treatments, a density change occurs (Figure 1). Regardless of the cultural culture, the highest density of the soil was on variants with zero treatment, slightly lower during surface treatment. The optimal density of the soil is noted on options with a dummy plowing. Mineral fertilizers with all methods of main processing contribute to the increase in soil density.
The experimental data obtained confirms the ambiguity of the effect of the methods of main soil processing on the indicators of its structural state (Table 1). Thus, on variants with zero treatment, the lowest content of agronomically valuable aggregates (10.0-0.25 mm) was noted in arable layer of the soil, with respect to surface treatment and dummy plowing.
Dumping surface mooler
processing treatment
Method of main soil processing
Figure 1 - Change in the density of the chernozem typical depending on the processing and fertilizer methods under winter wheat (2009) and corn (2010)
Nevertheless, the coefficient of structural characterizing the aggregate state decreased in a row: surface treatment ^ Dumping plow ^ Zero treatment. The structural and aggregate state of the chernozem affects not only the method of processing the soil, but also cultivated culture. When cultivating winter wheat, the number of agronomically valuable range aggregates and the structure coefficient were higher by an average of 20% than in the soil under corn. This is due to the biological peculiarities of the structure of the root system of these crops.
Considering the fertilizer factor, I would like to note that the use of fertilizers led to a noticeable decrease in both agronomically valuable structure and the structural coefficient, which is quite natural, since the first and second year after the introduction there is a deterioration in the structure of the aggregates and the agricultural properties of the soil - the density of the installation of aggregates is increasing , the fullness of the pore space is a finely dispersed part, the porosity decreases and the graininess is almost twice.
Table 1 - the effect of the method of processing soil and mineral fertilizers on the indicators of structural
Another indicator of the structure is its resistance to external influences, among which the most significant is the effect of water, since the soil must maintain its unique lump-grain structure after heavy precipitation and subsequent drying. This quality structure is called waterproofing or water-strength.
The content of water supply units (\u003e 0.25 mm) is a criterion for assessing and predicting the stability of the arable layer in time, its resistance to the degradation of physical properties under the influence of natural and anthropogenic factors. The optimal content of water supply units\u003e 0.25 mm in arable layer different types Soil is 40-70 (80)%. When studying the effects of the methods of main processing (Table 2), it was found that with zero treatment, the sum of waterproof units was higher than when surface treatment and a dummy plowing.
Table 2 - Waterproof Change Macro
This is directly related to the weighted average diameter of waterproof units, since zero treatment contributes to an increase in the size of the soil separates with waterproofing. The coefficient of the structure of waterproof units decreases in a row: surface treatment ^ Zero treatment ^ Unscake plowing. According to the estimated
the estimated scale of the criterion of water-strength of the aggregates at zero treatment is estimated as very good, and with superficial processing and dumped plowing - as good.
Studying the effect of the cultivated culture, it was found that in the soil under the corn, the weighted average diameter, the structure coefficient, and the amount of waterproof units were higher than under winter wheat, which is associated with the formation of the root system powerful in grain crops, which contributed to the formation greater waterproof under the corn. The water supply criterion behaved otherwise and was higher in the soil under wheat than under the corn.
When applying fertilizers in an embodiment with a dummy plowing, the structural coefficient, the weighted average diameter and the sum of waterproof aggregates increased. Since the dumping plowing comes with a turnover of the reservoir and significantly deeper than the surface and the greater the zero treatment, the sealing of mineral fertilizers is deeper, therefore, on the deep-binary humidity above, which contributes to a more intensive decomposition of plant residues, due to which the increase occurs waterproofing soil. At the embodiments using surface and zero treatments, all studied waterproofing indicators of the soil during the use of mineral fertilizers decreased. The criterion of water supply of soil units in all versions of experience increased, which is due to the fact that this indicator is calculated from the results of not only wet sifting, but also dry sifting.
The ambiguous effect of the studied factors on the indicators of the agrophysical state of the chernozem is typical. Thus, the most optimal density indicators, the structural state were revealed during a dumped plowing, somewhat worse with surface and zero treatments. Waterproofing indicators decreased in a row: zero treatment ^ Surface treatment ^ Dumping plowing. The use of mineral fertilizers impairs the structural-aggregate state, but helps to increase the waterproofability of the soil separates with a dummy plowing relative to zero and surface treatment. When cultivating winter wheat, indicators characterizing structural
Organic fertilizers There are substances of plant-animal origin, which are introduced into the soil in order to improve the agrochemical properties of the soil and increase the yield. As organic fertilizers apply different kinds manure, bird litter, compost, green fertilizer. Organic fertilizers have a versatile effect on agronomic properties:
- in their composition, all the necessary plants come to the soil nutrients. Each ton of dry substance of the CRP 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. - Such fertilizer is called full.
- in contrast to mineral fertilizers, organic fertilizers for the supply of nutrients are less concentrated,
- manure and other organic fertilizers serve for plants with source CO2. When in the soil 30 - 40 tons of manure, during the day in the period of intensive decomposition, it is allocated for the day 100 - 200 kg / ha CO2.
- organic fertilizers - energy material and food source for soil microorganisms.
- a significant portion of nutrients in organic fertilizers become available plants only as they are mineralized. That is, organic fertilizers have aifference, since the elements of them are used for 3-4 years.
- the efficiency of manure depends on climatic conditions and decreases from north to south and from west to east.
- the introduction of organic fertilizers is a fairly expensive event - there are high costs for transportation, the introduction of fuel, depreciation and technical care.
Ledicultural manure - Composite parts are solid and liquid excrement of animals and a litter. Chemical composition largely depends on the litter, its type and quantity, the type of animals, consumed feed, the storage method. Solid and liquid extraction of animals are unequal in composition and helpful qualities. Almost all phosphorus enters solid discharge, it is very small in liquid. About 1/2 - 2/3 of nitrogen and almost all potassium in the feed are distinguished with urine animals. N and R solid discharge become available plants only after their mineralization, while potassium is in mobile form. All nutrients of liquid selection are presented in easily soluble or lung.
Litter- when adding to manure increases its output, improves its quality and reduces the loss of nitrogen and alive in it. As a litter, they use: straw, peat, sawdust, etc. during storage in manure occurs with the participation of microorganisms, the process of decaying solid discharges with the formation of simpler. In liquid discharges, the urea is contained (NN2) 2, Hypuric acid C6H5COnNP2Cone and urinary acid C5H4No3 which can be detected to free NN3 two forms N-protein and ammonia-entraths.
According to the degree of decomposition, the fresh, semi-proverse, overwhelming and humus is distinguished.
Humus - rich in organic substance black homogeneous weight of 25% of the initial.
Terms of application - manure increases the harvest for several years. In the arid and extremely arid zone, the follow-up exceeds the action. The greatest effect of manure is achieved when it is applied to the chilly plowing, with immediate sealing into the soil. Making manure B. winter time It leads to significant losses NO3 and NN4 and 40-60% reduces its effectiveness. The norms of fertilizer in crop rotation should be established, taking into account the increase or conservation of the content of humus at the initial level. To do this, on black-earth soils, saturation of 1 hectares of crop rotation should be 5 - 6 tons, on brown - 3 - 4 tons.
Dose of manure 10 - 20 t / ha - arid, 20 - 40 tons - in insufficient provision of moisture. The most responsive technical crops are 25 - 40 t / ha. Under winter wheat 20 - 25 t / ha under the predecessor.
Straw- An important source of organic fertilizers. The chemical composition of the straw varies quite widely depending on the soil and weather conditions. It contains about 15% H2O and approximately 85% consists of organic matter (cellulism, penetration, hemocyllyloose and hygnin), which is a carbonic energy material for soil microorganisms, the basis building material For humus synthesis. The straw has 1-5% protein and only 3-7% ash. The composition of organic substances of the straw includes all the nutrients needed by plants, which are mineralized in easily accessible forms in 1 g. The straw is on average, 4-7 n, 1-1,4 Р2O5, 12-18 K2O, 2-3 kg , 0.8-1.2 kg of mg, 1-1.6 kg s, 5 g of boron, 3 g Cu, 30 g Mn. 40 g Zn, 0.4 MO, etc.
When assessing straw as organic fertilizer, not only the presence of certain substances, but also the ratio of C: n is of great importance. It has been established that for its normal decomposition, the ratio C: n should be 20-30: 1.
The positive effect of straw on the fertility of the soil and the harvest of S.-H. cultures are possible if required conditions For its decomposition. The rate of decomposition depends: on the presence of power sources for microorganisms, their number, species composition, such as soil, its obuity, temperature, humidity, aeration.
Dung Zhig. It is mainly a 1,000-l, 170 liters are distinguished by the urine of animals in 4 months from 10 tons, with dense storage, with a loose-denomated 450 l and with a loose-1000 l. On average, the dung is contained N-0.25 -0.3%, P2O5-0.03-0.06% and potassium - 0.4-0.5% - mostly nitrogen-potassium fertilizer. All nutrients in it are in easily accessible for plants form, so it is considered high-speed fertilizer. Coefficient of use 60-70% for N and K.
Bird litter - This is a valuable high-speed organic, concentrated fertilizer containing all the basic nutrients required by plants. So in chicken bird, there is 1.6% N, 1.5 P2O5, 0.8% K2O, 2.4 CAO, 0.7 MGO, 0.4 SO2. In addition to trace elements, its composition includes trace elements, MN, Zn, CO, CU. The amount of nutrients in the bird temperature largely depends on the feeding conditions of the bird and the poultry content.
The main way of keeping the bird two: outdoor and cellular. With outdoor content, a deep outstanding berophes, straw, corn rods is quite widely used. In cellular content of the bird, it is diluted with water than the concentration of nutrients decreases and significantly increases the costs of use as fertilizer. Raw bird liter is characterized by adverse physical properties that impede use mechanization. It has a number of other negative properties: extends to long distances an unpleasant smell, contains a huge number of weeds, a source of pollution ambient and a natural pathogenic microflora.
Green manure - Fresh vegetable mass, smelted into the soil to enrich it with organic matter and nitrogen. Often, this technique is called the Sideration, and the plants grown on fertilizer, Siderats. The legume plants are cultivated in the South-Russian steppe as the Siderates - Seretell, the Donnik, Masha, Esparcet, China, Vika, Peas Sowing Winter and Winter, Vika Ozimaya, Peas of Ferry (Pelyushka), Astragal; Cabbage - winter and spring rapes and spring, mustard, as well as their mixtures with bean crops. As the proportion of the legume component decreases in the mixture, the admission of nitrogen is reduced, which is compensated by a much more biological mass.
Green, like any organic fertilizer, has a multilateral positive effect on agrochemical properties Soil and yield of crops. Depending on the cultivation conditions on each hectare of pashnya, it increases and places from 25 to 50 t / ha green mass of the Siderators. In the biological mass of green fertilizers, there is a noticeable amount of nitrogen and especially phosphorus and potassium compared to the manure.
Fertilizers replenish the reserves of batteries in the soil in an affordable form and supply plants. At the same time, they have a great influence on the properties of the soil and thereby affect the harvest also indirectly. Raising plant yields and roots mass, fertilizers enhance the positive effect of plants on the soil, contribute to the increase in humus in it, improving its chemical, water and biological properties. A large direct positive effect on all these properties of the soil are organic fertilizers (manure, composts, green fertilizer).
Sour mineral fertilizers, if they are systematically used without organic fertilizers (and on acidic soils without lime), can have a negative effect on the soil properties (Table 123). The long-term use of them on acidic unknown soils leads to a decrease in soil saturation with bases, increases the content of toxic compounds of aluminum and toxic microorganisms, worsens the water-physical properties of the soil, increases volume weight (density), reduces the patriness of the soil, its aeration and water permeability. As a result of the deterioration of the properties of the soil, the increases of crops from fertilizers are reduced, the negative effects of acidic fertilizers on the harvest are shifted.
The negative effect of acidic mineral fertilizers on the properties of acidic soils is associated not only with the free acidity of fertilizers, but also with the action of their bases to the absorbing complex of the soil. Out of exchange hydrogen and aluminum, they convert the soil exchange acidity into active and at the same time the soil solution is strongly acidified, dispersing the bonding colloid structure and reducing its strength. Therefore, when making large doses of mineral fertilizers, not only the acidity of the fertilizer themselves should be taken into account, but also the value of the soil metabolism.
Lime neutralizes soil acidity, improves its agrochemical properties and eliminates the negative effect of acidic mineral fertilizers. Even small doses of lime (from 0.5 to 2 t / ha) increase the saturation of the soil bases, lower the acidity and sharply reduce the amount of toxic aluminum, which in acidic podzolic soils has an exceptionally severe negative effect on the growth and crop of plants.
In long-term experiments using acidic mineral fertilizers on chernozem, there is also a slight increase in soil acidity and a decrease in the amount of metabolic reasons (Table 124), which can be eliminated by entering small quantities Lime.
A large and always positive effect on all soils are organic fertilizers. Under the influence of organic fertilizers - manure, peat composts, siturates - the content of humus increases, increases the saturation of the soil by the bases, including calcium, the biological and physical properties of the soil (treatment, moisture intensity, water permeability) are improved, and acidity, maintenance decreases in soils with an acidic reaction Toxic compounds of aluminum and toxic microorganisms. However, a significant increase in the content of humus in the soil and the improvement of physical properties is noted only with the systematic making of large doses of organic fertilizers. Single introduction to acidic soils together with lime improves the high-quality group composition of humus, but does not lead to a noticeable increase in its percentage content in the soil.
In the same way, the peat introduced into the soil without prior composting does not have a noticeable positive effect on the properties of the soil. Its effect on the soil increases sharply, if it is pre-composed with manure, dung alkaline, feces or mineral fertilizers, especially alkaline, since the peat itself decomposes very slowly and in acidic soils forms many highly dispersed fulvocoslotes that support the acidic reaction of the medium.
A large positive effect on the soil has a joint introduction of organic fertilizers with minerals. At the same time, the number and activity of nitrifying bacteria and bacteria, fixing the atmospheric nitrogen, oligonythilic, free-lived nitrogen, and others increase in acidic podzolic soils, and others. In acidic podzolic soils, the number of microorganisms on the Aristovsky environment, which, in its opinion, produce a large number of Strong acids, appeolating the soil.
Currently, fertilizers are treated as an integral part of the agriculture system, as one of the main means, stabilizing the yield in drought conditions. The volume of applying fertilizers grow continuously and it is very important to apply them effectively and rationally.
Organic fertilizers contain nutrients, mainly as part of organic compounds, and are usually products of natural origin (manure, peat, straw, feces, etc.). In a separate group, bacterial fertilizers are isolated, which contain cultures of microorganisms that contribute to the accumulation of the forms of nutrient elements in the soil. (Yagodin B. A., Agrochemistry, 2002)
Organic fertilizers, especially manure, have a good and sustainable effect on all soils, especially at the brainstant and salthold soils. With systematic application of manure, soil fertility increases; In addition, heavy clay soils become loose and water permeable, and light (sandy) are more connected, moisturizers. Big effect gives a combination of mineral fertilizers with organic.
Mineral fertilizers are industrial or fossil products containing the elements necessary to supply plants and increase soil fertility. They are obtained from minerals by chemical or mechanical processing. This is mainly mineral salts, but they include some organic substances, such as urea. (Yagodin B. A., Agrochemistry, 2002)
The basis for the effectiveness of mineral fertilizers is differentiated taking into account soil-climatic and other factors and calculated depending on them doses for their introduction.
Nitrogen fertilizers increase the growth and development of plants. When this fertilizer is made on the meadows, the leaves and stalks of plants are developing stronger, becoming more powerful due to which the harvest is significantly increased. This is especially true for cereal plants.
Phosphoric fertilizers reduce the growing period of the vegetation of herbs, contribute to the rapid development of the root system and the deeper penetration into the soil, make plants more drought-resistant, which is especially valuable for lifric meadows.
With an increase in fertility fertilizer fertility decrease, which allows you to switch to the system of fertilizers in the links of crop rotations with a wide use of row phosphoric fertilizer.
Potassium fertilizers are stronger action on low-voltage and sudidal meadows with temporarily excessive moisture. Contribute to the accumulation of carbohydrates, and, consequently, the increase in the winter resistance of perennial forage herbs. Contribute potash fertilizers In the spring or after Zhosa, as well as in the fall.
Microfertilizers should be applied differentiated taking into account soil conditions and biological characteristics of plants.
When making microfertilizers to the soil, pays great attention to ensuring that they wash out as little as possible and for a longer time remained in the formations available for plants. Thus, the use of complex granular fertilizers reduces contact with the soil of microelements included in the granules. With this method of making trace elements, they are less transmitted to untapped forms.
With a qualified application of fertilizers, soil fertility, agriculture, fixed assets and foundations, labor productivity and its payment, net income and profitability of production are increasing.
Currently, an environmental crisis is observed. This is a really existing process caused by anthropogenic activities. Many local problems appear; Regional problems turn into global. Continuing air, water, lands, food products is constantly enhanced.
As a result anthropogenic exposureThe accumulation of heavy metals occurs in the soil, which negatively affects crops, its composition, concentration, reaction, and bufferiness of the soil solution are changed.
