About the negative impact of mineral fertilizers. Abstract: The hidden negative effect of fertilizers The effect of nitrogen fertilizers on plants
INFLUENCE OF SOIL TREATMENT AND MINERAL FERTILIZERS ON AGROPHYSICAL PROPERTIES OF TYPICAL CHERNOZEM
G.N. Cherkasov, E.V. Dubovik, D.V. Dubovik, S.I. Kazantsev
Annotation. As a result of the research, an ambiguous effect of the method of basic tillage for winter wheat and corn and mineral fertilizers on the indicators of the agrophysical state of typical chernozem has been established. Optimal indicators of density, structural state were obtained during moldboard plowing. It was revealed that the use of mineral fertilizers worsens the structural-aggregate state, but contributes to an increase in the water resistance of soil units during moldboard plowing in relation to zero and surface tillage.
Key words: structural-aggregate state, soil density, water resistance, tillage, mineral fertilizers.
Fertile soil, along with a sufficient content of nutrients, must have favorable physical conditions for the growth and development of crops. It has been established that soil structure is the basis of favorable agrophysical properties.
Chernozem soils have a low degree of anthropogenic tolerance, which suggests a high degree of influence of anthropogenic factors, the main of which is tillage, as well as a number of other measures that are used in caring for crops and contribute to the violation of a very valuable granular structure, as a result of which it can be sprayed or, conversely, clumping, which is permissible up to certain limits in the soil.
Thus, the purpose of this work was to study the effect of tillage, mineral fertilizers and the previous crop on the agrophysical properties of typical chernozem.
The studies were carried out in 2009-2010. in AgroSil LLC (Kursk region, Sudzhansky district), on typical heavy loamy chernozem. Agrochemical characteristics of the site: pHx1- 5.3; humus content (according to Tyurin) - 4.4%; mobile phosphorus (according to Chirikov) - 10.9 mg / 100 g; exchangeable potassium (according to Chirikov) - 9.5 mg / 100 g; alkaline hydrolysable nitrogen (according to Kornfield) - 13.6 mg/100 g. Cultivated crops: winter wheat varieties "Augusta" and corn hybrid PR-2986.
In the experiment, the following methods of basic tillage were studied: 1) moldboard plowing by 20-22 cm; 2) surface treatment - 10-12 cm; 3) zero tillage - direct sowing with John Deere seeder. Mineral fertilizers: 1) without fertilizers; 2) for winter wheat N2^52^2; for corn K14eR104K104.
Sampling was carried out in the third decade of May, in a layer of 0-20 cm. The density of the soil was determined by the drilling method according to N. A. Kachinsky. To study the structural-aggregate state, undisturbed soil samples weighing more than 1 kg were selected. To isolate structural units and aggregates, the method of N. I. Savvinov was used to determine the structural-aggregate composition of the soil - dry and wet sifting.
Soil density is one of the main physical characteristics of soil. An increase in soil density leads, as a rule, to a denser packing of soil particles, which in turn leads to a change in water, air and thermal regimes, which
subsequently negatively affects the development of the root system of agricultural plants. At the same time, the requirements of different plants for soil density are not the same and depend on the type of soil, mechanical composition, and cultivated crop. So, the optimal soil density for grain crops is 1.051.30 g/cm3, for corn - 1.00-1.25 g/cm3.
The conducted studies have shown that under the influence of various soil treatments, a change in density occurs (Figure 1). Regardless of the cultivated crop, the highest soil density was in no-till variants, slightly lower in surface tillage. The optimal soil density is noted in the variants with moldboard plowing. Mineral fertilizers with all methods of basic cultivation contribute to an increase in soil density.
The obtained experimental data confirm the ambiguity of the influence of the main tillage methods on the indicators of its structural state (Table 1). So, in the options with zero tillage, the lowest content of agronomically valuable aggregates (10.0-0.25 mm) in the arable soil layer was noted in relation to surface tillage and moldboard plowing.
Moldboard Surface Cooling
processing processing
Basic tillage method
Figure 1 - Change in the density of a typical chernozem depending on the methods of processing and fertilizers under winter wheat (2009) and corn (2010)
Nevertheless, the structural coefficient characterizing the state of aggregation decreased in the series: surface tillage ^ moldboard plowing ^ zero tillage. The structural and aggregate state of chernozem is influenced not only by the method of tillage, but also by the cultivated crop. When cultivating winter wheat, the number of aggregates of the agronomically valuable range and the coefficient of structure were higher on average by 20% than in the soil under corn. This is due to the biological features of the structure of the root system of these crops.
Considering the fertilization factor, I would like to note that the use of fertilizers led to a noticeable decrease in both the agronomically valuable structure and the structural coefficient, which is quite natural, since in the first and second years after the application, there is a deterioration in the structure of aggregates and agrophysical properties of the soil - the packing density of aggregates increases , the filling of the pore space with a finely dispersed part, the porosity decreases and the granularity decreases almost twice.
Table 1 - The influence of the method of tillage 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 impact of water, since the soil must retain its unique cloddy-granular structure after heavy rainfall and subsequent drying. This quality of the structure is called water resistance or water-strength.
The content of water stable aggregates (>0.25 mm) is a criterion for assessing and predicting the stability of the addition 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-stable aggregates >0.25 mm in the topsoil of different soil types is 40-70(80)%. When studying the influence of the main tillage methods (table 2), it was found that with zero tillage the amount of water-resistant aggregates was higher than with surface tillage and moldboard plowing.
Table 2 - Change in water resistance of macro-
This is directly related to the weighted average diameter of water resistant aggregates, since no-till increases the size of soil units that are water resistant. The structural coefficient of waterproof aggregates decreases in the series: surface tillage ^ zero tillage ^ moldboard plowing. According to the estimated
On an indicative scale, the criterion of water resistance of aggregates at zero tillage is assessed as very good, and at surface tillage and moldboard plowing - as good.
Studying the influence of the cultivated crop, it was found that in the soil under corn, the weighted average diameter, the coefficient of structure, as well as the sum of water-stable aggregates were higher than under winter wheat, which is associated with the formation of a powerful root system in terms of volume and weight under grain crops, which contributed to the formation greater water resistance under corn. The water resistance criterion behaved differently and was higher in the soil under wheat than under corn.
When applying fertilizers on the variant with moldboard plowing, the structure coefficient, the weighted average diameter and the sum of water-resistant aggregates increased. Since moldboard plowing goes with the turnover of the layer and is much deeper than surface and, especially, zero tillage, then the incorporation of mineral fertilizers occurs deeper, therefore, at a depth, the humidity is higher, which contributes to a more intensive decomposition of plant residues, due to which there is an increase soil water resistance. In the variants with the use of surface and zero tillage, all studied indicators of soil water resistance decreased when mineral fertilizers were applied. The criterion of water resistance of soil aggregates in all variants of the experiment increased, which is due to the fact that this indicator is calculated based on the results of not only wet sifting, but also dry sieving.
The ambiguous influence of the studied factors on the indicators of the agrophysical state of a typical chernozem has been established. So, the most optimal indicators of density, structural state were revealed during moldboard plowing, somewhat worse during surface and zero tillage. The indicators of water resistance decreased in the series: zero tillage ^ surface tillage ^ moldboard plowing. The use of mineral fertilizers worsens the structural-aggregate state, but contributes to an increase in the water resistance of soil units during moldboard plowing in relation to zero and surface tillage. When cultivating winter wheat, indicators characterizing the structural
Preservation and reproduction of soil fertility is a task of exceptional importance. This is of particular importance in modern agricultural conditions with a shortage of fertilizers and their high cost. The use of organic and mineral fertilizers is the most significant factor contributing to the preservation and improvement of soil fertility along with the impact on the overall level of crop yields.
The most important indicator of soil fertility is the content of organic matter, or humus, in the soil.
Humus affects the thermal, water, air properties of the soil, its absorption capacity and biological activity, it largely determines the agrophysical, physicochemical, agrochemical properties of the soil, and also serves as a reserve source of nutrients for plants. The yield of agricultural crops depends on the reserves of humus in the soil.
With insufficient fertilization, the crop yield is formed mainly due to soil reserves of nutrients, primarily nitrogen, released during the mineralization of humus.
To maintain a deficit-free balance of humus, the use of manure (or other organic fertilizers in equivalent amounts, depending on the degree of humification) should be 7–15 t/ha per year.
The results of many years of research in field experiments on soddy-podzolic soils of various granulometric composition show that when growing crops without fertilization, there is a significant decrease in organic matter in soils compared to the initial level and, as a result, a significant crop shortage. The systematic use of nutrient-balanced fertilizer systems, which primarily include complex, organo-mineral systems, helps to replenish humus reserves in soils, improve their phosphate and potassium regimes, which is accompanied by an increase in the productivity of cultivated crops and crop rotations in general. Organic (biological) fertilizer systems in the conditions of the Nonchernozem zone of Russia are inferior to organo-mineral ones in terms of crop productivity and do not have significant differences in the quality of plant products.
Liming and the application of organic fertilizers limit the entry into plants and the accumulation in commercial crops of a number of heavy metals, the mobility of which decreases when soils are neutralized and due to sorption by organic matter and the formation of organometallic complexes with it.
One of the methods for increasing soil fertility is the integrated agrochemical cultivation of fields, which was introduced into agriculture in the 80s of the last century. This method provides for in the shortest possible time, through the complex application of mineral and organic fertilizers, ameliorants and plant protection products, to increase soil fertility to the optimum level and ensure the planned yield of crops in crop rotation.
The use of mineral and organic fertilizers on the soils of the CCR replenishes the reserves of available forms of nitrogen, phosphorus and potassium, and increases crop yields. This is evidenced by numerous data obtained in research institutions.
Under the conditions of the chernozem type of soil formation, phosphorus always remains the limiting element in the formation of the productivity of grain crops, and under the conditions of gray forest soils, both phosphorus and potassium are such. This means that potassium is a limiting element not only for gray forest soils, but also for soddy-podzolic soils that form under more humid conditions.
The results of soil fertility monitoring carried out by the agrochemical service show a decrease in soil organic matter and basic nutrients, which negatively affects the productivity and economic efficiency of agricultural production. Currently, 31% of arable land has high acidity, 52%? low humus content, 22%? lack of phosphorus and 9% ? lack of potassium.
If you have read the articles that I posted in previous posts, you now understand how the symbiosis of worms, plants and soil microflora works.
So, let's sum up.
Plants with their fruits and their humus (leaves, stems, roots, etc.) attract soil microflora to their roots. The plant itself cannot directly take all the necessary substances from the soil. They invite bacteria and fungi, which, with the help of their enzymes, digest all organic matter, making the so-called broth, which they "eat" themselves and which the plants "eat". Then some of the bacteria that multiply strongly in the process of feeding are eaten by earthworms. Digesting bacteria and the remains of the broth, the worms "produce" the actual humus. And humus is a repository of a whole complex of substances that make the soil fertile. Humus, as it were, accumulates these substances, preventing them from being washed out of the soil by water and other natural factors and leading to soil degradation and erosion.
Thus, it becomes clear that if you somehow influence the process of creating humus, the process of plant nutrition, this unique symbiosis of microflora, worms and plants, you can disrupt the process of humus production and the process of normal plant nutrition.
This is what modern traditional agriculture does. It introduces tons of chemicals into the earth, disrupting the harmonious balance of microflora.
It is now clear that soil fertility depends on the health of soil microflora.
But herbicides and pesticides kill this microflora. Kill completely. Proof of this, our friend the farmer - he says that where he does not put mineral fertilizers, potatoes do not grow there at all - the bushes grow up to 10 cm in height and that's it, the tubers do not want to tie at all. And he believes that there is only one way out - to put more mineral fertilizers. And every year more and more...
Plants on mineral fertilizers are drug addicts. These plants are "sitting on doping", on drugs. Everything would be fine, but only plants cannot directly digest these fertilizers, they still need microflora. But this microflora is destroyed more and more every year by chemicals and mineral fertilizers themselves. Here is a quote from a site about gardening: "
mineral fertilizers change the qualitative composition of soil microorganisms, destroy the molecules of humic acids, fertility is disturbed or disappears altogether, since the soil structure is disturbed, often, which seemed like lifeless dust, the soils are simply taken out of use "(http://www.7dach.ru/VeraTyukaeva/unikalnye-guminovye-kisloty-21195.html
)
And here is another article for you about the effect of mineral fertilizers on soil and humans: (based on materials from the site http://sadisibiri.ru/mineralnie-udobrebiya-vred-polza.html)
Mineral fertilizers: benefits and harms
Yes, the harvest from them is growing,
But nature is being destroyed.
People eat nitrates
More and more every year.
The global production of mineral fertilizers is growing rapidly. Every decade it increases by about 2 times. The yield of crops from their use, of course, is growing, but this problem has many negative aspects, and this worries a lot of people. It is not for nothing that in some Western countries the government supports vegetable growers who grow products without the use of mineral fertilizers - environmentally friendly.
MIGRATION OF NITROGEN AND PHOSPHORUS FROM SOIL
It has been proven that about 40% of the nitrogen introduced into the soil is absorbed by plants, the rest of the nitrogen is washed out of the soil by rain and volatilizes in the form of gas. To a lesser extent, but washed out of the soil and phosphorus. The accumulation of nitrogen and phosphorus in groundwater leads to pollution of water bodies, they quickly age and turn into swamps, because. the increased content of fertilizers in the water entails the rapid growth of vegetation. Dying plankton and algae settle to the bottom of water bodies, this leads to the release of methane, hydrogen sulfide and a reduction in water-soluble oxygen reserves, which causes fish to die. The species composition of valuable fish is also declining. The fish did not grow to normal sizes, it began to age earlier, to die earlier. Plankton in water bodies accumulate nitrates, fish feed on them, and eating such fish can lead to stomach diseases. And the accumulation of nitrogen in the atmosphere leads to acid rain, which acidifies the soil and water, destroys building materials, and oxidizes metals. Forests and the animals and birds living in them suffer from all this, and fish and mollusks die in reservoirs. There is a report that on some plantations where mussels are mined (these are edible mollusks, they used to be very much appreciated), they became inedible, moreover, there were cases of poisoning by them.
INFLUENCE OF MINERAL FERTILIZERS ON SOIL PROPERTIES
Observations show that the content of humus in soils is constantly decreasing. Fertile soils, chernozems at the beginning of the century contained up to 8% humus. Now there are almost no such soils left. Podzolic and soddy-podzolic soils contain 0.5-3% humus, gray forest soils - 2-6%, meadow chernozems - more than 6%. Humus serves as a repository of the main plant nutrients, it is a colloidal substance, the particles of which hold the nutrients on their surface in a form accessible to plants. Humus is formed during the decomposition of plant residues by microorganisms. Humus cannot be replaced by any mineral fertilizers, on the contrary, they lead to active mineralization of humus, the soil structure deteriorates, from colloidal lumps that retain water, air, nutrients, the soil turns into a dusty substance. From natural soil turns into artificial. Mineral fertilizers provoke leaching of calcium, magnesium, zinc, copper, manganese, etc. from the soil, this affects the processes of photosynthesis, reduces the resistance of plants to diseases. The use of mineral fertilizers leads to soil compaction, a decrease in its porosity, and a decrease in the proportion of granular aggregates. In addition, soil acidification, which inevitably occurs when mineral fertilizers are applied, requires an increasing amount of lime. In 1986, 45.5 million tons of lime were applied to the soil in our country, but this did not compensate for the loss of calcium and magnesium.
SOIL POLLUTION WITH HEAVY METALS AND TOXIC ELEMENTS
The raw materials used for the production of mineral fertilizers contain strontium, uranium, zinc, lead, cadmium, etc., which are technologically difficult to extract. As impurities, these elements are included in superphosphates, in potash fertilizers. The most dangerous heavy metals: mercury, lead, cadmium. The latter destroys erythrocytes in the blood, disrupts the functioning of the kidneys, intestines, and softens tissues. A healthy person weighing 70 kg without harm to health can receive with food per week up to 3.5 mg of lead, 0.6 mg of cadmium, 0.35 mg of mercury. However, on heavily fertilized soils, plants can accumulate high concentrations of these metals. For example, in the milk of cows there can be up to 17-30 mg of cadmium per 1 liter. The presence of uranium, radium, thorium in phosphate fertilizers increases the level of internal exposure of humans and animals when plant foods enter their bodies. The composition of superphosphate also includes fluorine in an amount of 1-5%, and its concentration can reach 77.5 mg / kg, causing various diseases.
MINERAL FERTILIZERS AND THE LIVING WORLD OF SOIL
The use of mineral fertilizers causes a change in the species composition of soil microorganisms. The number of bacteria capable of assimilating mineral forms of nitrogen greatly increases, but the number of symbiotic microfungi in the plant rhizosphere decreases (the rhizosphere is a 2–3 mm soil area adjacent to the root system). The number of nitrogen-fixing bacteria in the soil also decreases - they seem to be no longer needed. As a result, the root system of plants reduces the release of organic compounds, and their volume was about half the mass of the above-ground part, and plant photosynthesis is reduced. Toxin-forming microfungi are activated, the number of which is naturally controlled by beneficial microorganisms. The introduction of lime does not save the situation, but sometimes leads to an increase in soil contamination with root rot pathogens.
Mineral fertilizers cause severe depression of soil animals: springtails, roundworms and phytophages (they feed on plants), as well as a decrease in the enzymatic activity of the soil. And it is formed by the activity of all soil plants and living creatures of the soil, while enzymes enter the soil as a result of their release by living organisms, dying microorganisms. It has been established that the use of mineral fertilizers reduces the activity of soil enzymes by more than two times.
HUMAN HEALTH PROBLEMS
In the human body, nitrates that enter food are absorbed into the digestive tract, enter the bloodstream, and with it - into the tissues. About 65% of nitrates are converted to nitrites already in the oral cavity. Nitrites oxidize hemoglobin to metahemoglobin, which has a dark brown color; it is unable to carry oxygen. The norm of metahemoglobin in the body is 2%, and more of it causes various diseases. At 40% methaemoglobin in the blood, a person can die. In children, the enzymatic system is poorly developed, and therefore nitrates are more dangerous for them. Nitrates and nitrites in the body turn into nitroso compounds, which are carcinogens. In experiments on 22 animal species, it was proved that these nitroso compounds cause the formation of tumors on all organs except bones. Nitrosamines, having hepatotoxic properties, also cause liver disease, in particular hepatitis. Nitrites lead to chronic intoxication of the body, weaken the immune system, reduce mental and physical performance, exhibit mutagenic and embryotoxic properties.
For vegetables, limit norms for the content of nitrates in mg / kg have been established. These standards are constantly being adjusted upwards. The level of the maximum permissible concentration of nitrates, now adopted in Russia, and the optimal soil acidity for some vegetables are given in the table (see below).
The actual content of nitrates in vegetables, as a rule, exceeds the norm. The maximum daily dose of nitrates that does not adversely affect the human body - 200-220 mg per 1 kg of body weight. As a rule, 150-300 mg, and sometimes up to 500 mg per 1 kg of body weight, actually enter the body. By increasing the yield of crops, mineral fertilizers affect their quality. In plants, the content of carbohydrates decreases and the amount of crude protein increases. In potatoes, the starch content decreases, and in grain crops, the amino acid composition changes, i.e. protein nutrition is reduced.
The use of mineral fertilizers in the cultivation of crops also affects the storage of products. A decrease in sugar and dry matter in beets and other vegetables leads to a deterioration in their keeping quality during storage. In potatoes, the flesh darkens more strongly; when canning vegetables, nitrates cause corrosion of the metal of cans. It is known that nitrates are more in the veins of leaves in lettuces, spinach, up to 90% of nitrates are concentrated in the core of carrots, up to 65% in the upper part of beets, their amount increases when juice and vegetables are stored at high temperatures. It is better to harvest vegetables from the garden when they are ripe and in the afternoon - then they have less nitrates. Where do nitrates come from, and when did this problem arise? Nitrates have always been in the products, just their number has been growing recently. The plant feeds, takes nitrogen from the soil, nitrogen accumulates in the tissues of the plant, this is a normal phenomenon. Another thing is when there is an excess amount of this nitrogen in the tissues. Nitrates by themselves are not dangerous. Some of them are excreted from the body, the other part is converted into harmless and even useful compounds. And the excess part of nitrates turns into salts of nitrous acid - these are nitrites. They also deprive the red blood cells of the ability to nourish the cells of our body with oxygen. As a result, metabolism is disturbed, the central nervous system suffers, and the body's resistance to diseases decreases. Among vegetables, the champion in the accumulation of nitrates is beets. Less of them in cabbage, parsley, onions.
The use of mineral fertilizers (even in high doses) does not always lead to the predicted increase in yield.
Numerous studies indicate that the weather conditions of the growing season have such a strong influence on the development of plants that extremely unfavorable weather conditions actually neutralize the effect of increasing yields even at high doses of nutrients (Strapenyants et al., 1980; Fedoseev, 1985). The coefficients of use of nutrients from mineral fertilizers can differ sharply depending on the weather conditions of the growing season, decreasing for all crops in years with insufficient moisture (Yurkin et al., 1978; Derzhavin, 1992). In this regard, any new methods to improve the efficiency of mineral fertilizers in areas of unsustainable agriculture deserve attention.
One of the ways to increase the efficiency of the use of nutrients from fertilizers and soil, strengthen plant immunity to adverse environmental factors and improve the quality of the products obtained is the use of humic preparations in the cultivation of crops.
Over the past 20 years, interest in humic substances used in agriculture has increased significantly. The topic of humic fertilizers is not new either for researchers or for agricultural practitioners. Since the 50s of the last century, the effect of humic preparations on the growth, development, and yield of various crops has been studied. Currently, due to a sharp rise in the price of mineral fertilizers, humic substances are widely used to increase the efficiency of the use of nutrients from the soil and fertilizers, increase plant immunity to adverse environmental factors and improve the quality of the crop of the products obtained.
Diverse raw materials for the production of humic preparations. These can be brown and dark coals, peat, lake and river sapropel, vermicompost, leonardite, as well as various organic fertilizers and waste.
The main method for obtaining humates today is the technology of high-temperature alkaline hydrolysis of raw materials, which results in the release of surface-active high-molecular organic substances of various masses, characterized by a certain spatial structure and physico-chemical properties. The preparative form of humic fertilizers can be a powder, paste or liquid with different specific gravity and concentration of the active substance.
The main difference for various humic preparations is the form of the active component of humic and fulvic acids and (or) their salts - in water-soluble, digestible or indigestible forms. The higher the content of organic acids in a humic preparation, the more valuable it is both for individual use and especially for obtaining complex fertilizers with humates.
There are various ways of using humic preparations in crop production: processing of seed material, foliar top dressing, introduction of aqueous solutions into the soil.
Humates can be used both separately and in combination with plant protection products, growth regulators, macro- and microelements. The range of their use in crop production is extremely wide and includes almost all agricultural crops produced both in large agricultural enterprises and in personal subsidiary plots. Recently, their use in various ornamental crops has grown significantly.
Humic substances have a complex effect that improves the condition of the soil and the system of interaction "soil - plants":
- increase the mobility of assimilable phosphorus in soil and soil solutions, inhibit immobilization of assimilable phosphorus and retrogradation of phosphorus;
- radically improve the balance of phosphorus in soils and phosphorus nutrition of plants, which is expressed in an increase in the proportion of organophosphorus compounds responsible for the transfer and transformation of energy, the synthesis of nucleic acids;
- improve soil structure, their gas permeability, water permeability of heavy soils;
- maintain the organo-mineral balance of soils, preventing their salinization, acidification and other negative processes leading to a decrease or loss of fertility;
- shorten the vegetative period by improving protein metabolism, concentrated delivery of nutrients to the fruit parts of plants, saturating them with high-energy compounds (sugars, nucleic acids, and other organic compounds), and also suppress the accumulation of nitrates in the green part of plants;
- enhance the development of the root system of the plant due to good nutrition and accelerated cell division.
Particularly important are the beneficial properties of humic components for maintaining the organo-mineral balance of soils under intensive technologies. In the article by Paul Fixen "The concept of increasing the productivity of crops and the efficiency of using nutrients by plants" (Fixen, 2010), a link is given to a systematic analysis of methods for assessing the efficiency of using nutrients by plants. As one of the significant factors affecting the efficiency of the use of nutrients, the intensity of crop cultivation technologies and the associated changes in the structure and composition of the soil, in particular, the immobilization of nutrients and the mineralization of organic matter, are indicated. Humic components in combination with key macronutrients, primarily phosphorus, maintain soil fertility under intensive technologies.
In the work of Ivanova S.E., Loginova I.V., Tyndall T. “Phosphorus: mechanisms of losses from the soil and ways to reduce them” (Ivanova et al., 2011), the chemical fixation of phosphorus in soils is noted as one of the main factors of a low degree the use of phosphorus by plants (at the level of 5 - 25% of the amount of phosphorus introduced in the 1st year). Increasing the degree of phosphorus use by plants in the year of application has a pronounced environmental effect - reducing the ingress of phosphorus with surface and underground runoff into water bodies. The combination of the organic component in the form of humic substances with the mineral in fertilizers prevents the chemical fixation of phosphorus into poorly soluble calcium, magnesium, iron and aluminum phosphates and retains phosphorus in a form available to plants.
In our opinion, the use of humic preparations in the composition of mineral macrofertilizers is very promising.
Currently, there are several ways to introduce humates into dry mineral fertilizers:
- surface treatment of granulated industrial fertilizers, which is widely used in the preparation of mechanical fertilizer mixtures;
- mechanical introduction of humates into powder with subsequent granulation in small-scale production of mineral fertilizers.
- introduction of humates into the melt during large-scale production of mineral fertilizers (industrial production).
The use of humic preparations for the production of liquid mineral fertilizers used for foliar treatment of crops has become very widespread in Russia and abroad.
The purpose of this publication is to show the comparative effectiveness of humated and conventional granular mineral fertilizers on grain crops (winter and spring wheat, barley) and spring rapeseed in various soil and climatic zones of Russia.
Sodium humate Sakhalin was chosen as a humic preparation to obtain guaranteed high results in terms of agrochemical efficiency with the following indicators ( tab. 1).
The production of Sakhalin humate is based on the use of brown coal from the Solntsevo deposit on Sakhalin, which have a very high concentration of humic acids in digestible form (more than 80%). Alkaline extract from brown coals of this deposit is almost completely soluble in water, non-hygroscopic and non-caking powder of dark brown color. Microelements and zeolites also pass into the composition of the product, which contribute to the accumulation of nutrients and regulate the metabolic process.
In addition to the indicated indicators of Sakhalin sodium humate, an important factor in its choice as a humic additive was the production of concentrated forms of humic preparations in industrial quantities, high agrochemical indicators of individual use, the content of humic substances mainly in water-soluble form and the presence of a liquid form of humate for uniform distribution in the granule in industrial production, as well as state registration as an agrochemical.
In 2004, Ammofos JSC in Cherepovets produced an experimental batch of a new type of fertilizer - azophoska (nitroammophoska) grade 13:19:19, with the addition of Sakhalin sodium humate (alkaline extract from leonardite) into the pulp according to technology, developed at OAO NIUIF. The quality indicators of humated ammophoska 13:19:19 are given in tab. 2.
The main task during industrial testing was to substantiate the optimal method for introducing the Sakhalin humate additive while maintaining the water-soluble form of humates in the product. It is known that humic compounds in acidic environments (at pH<6) переходят в формы водорастворимых гуматов (H-гуматы) с потерей их эффективности.
The introduction of powdered humate "Sakhalinsky" into the recycle in the production of complex fertilizers ensured that the humate did not come into contact with an acidic medium in the liquid phase and its undesirable chemical transformations. This was confirmed by the subsequent analysis of finished fertilizers with humates. The introduction of humate actually at the final stage of the technological process determined the preservation of the achieved productivity of the technological system, the absence of return flows and additional emissions. There was also no deterioration in physicochemical complex fertilizers (caking, granule strength, dustiness) in the presence of a humic component. The hardware design of the humate injection unit also did not present any difficulties.
In 2004, CJSC "Set-Orel Invest" (Oryol region) conducted a production experiment with the introduction of humated ammophosphate for barley. The increase in barley yield on an area of 4532 hectares from the use of humated fertilizer compared to the standard ammophos grade 13:19:19 was 0.33 t/ha (11%), the protein content in the grain increased from 11 to 12.6% ( tab. 3), which gave the farm an additional profit of 924 rubles/ha.
In 2004, field experiments were conducted at the SFUE OPH "Orlovskoye" All-Russian Research Institute of Legumes and Cereals (Oryol Region) to study the effect of humated and conventional ammophoska (13:19:19) on the yield and quality of spring and winter wheat.
Experiment scheme:
- Control (no fertilizer)
N26 P38 K38 kg a.i./ha
N26 P38 K38 kg a.i./ha humated
N39 P57 K57 kg a.i./ha
N39 P57 K57 kg a.i./ha humated.
In the experiment with spring wheat (variety Smena), the maximum yield of 2.78 t/ha was also observed when an increased dose of humated fertilizer was applied. In the same variant, the highest content of protein and gluten in the grain was observed. As in the experiment with winter wheat, the application of humated fertilizer statistically significantly increased the yield and the content of protein and gluten in the grain compared to the application of the same dose of standard mineral fertilizer. The latter works not only as an individual component, but also improves the absorption of phosphorus and potassium by plants, reduces the loss of nitrogen in the nitrogen cycle of nutrition, and generally improves the exchange between soil, soil solutions and plants.
A significant improvement in the quality of the crop and winter and spring wheat indicates an increase in the efficiency of mineral nutrition of the production part of the plant.
According to the results of the action, the humate additive can be compared with the influence of microcomponents (boron, zinc, cobalt, copper, manganese, etc.). With a relatively small content (from tenths to 1%), humate additives and microelements provide almost the same increase in yield and quality of agricultural products. The work (Aristarkhov, 2010) studied the effect of microelements on the yield and quality of grain of cereals and legumes and showed an increase in protein and gluten on the example of winter wheat with the main application on various types of soil. The directed influence of microelements and humates on the productive part of crops is comparable in terms of the results obtained.
High agrochemical production results with minimal refinement of the instrumentation scheme for large-scale production of complex fertilizers, obtained from the use of humated ammophoska (13:19:19) with Sakhalin sodium humate, made it possible to expand the range of humated grades of complex fertilizers with the inclusion of nitrate-containing grades.
In 2010, OJSC Mineralnye Udobreniya (Rossosh, Voronezh Region) produced a batch of humated azophoska 16:16:16 (N:P 2 O 5:K 2 O) containing humate (alkaline extract from leonardite) - not less than 0.3% and moisture - not more than 0.7%.
Azofoska with humates was a light gray granular organomineral fertilizer, differing from the standard one only in the presence of humic substances in it, which gave a barely noticeable light gray tint to the new fertilizer. Azofoska with humates was recommended as an organo-mineral fertilizer for the main and “before sowing” application to the soil and for root dressings for all crops where conventional azofoska can be used.
In 2010 and 2011 On the experimental field of the State Scientific Institution Moscow Research Institute of Agriculture "Nemchinovka", studies were carried out with humated azophos produced by JSC "Mineral Fertilizers" in comparison with the standard one, as well as with potash fertilizers (potassium chloride) containing humic acids (KaliGum), in comparison with the traditional potash fertilizer KCl.
Field experiments were carried out according to the generally accepted methodology (Dospekhov, 1985) on the experimental field of the Moscow Research Institute of Agriculture "Nemchinovka".
A distinctive feature of the soils of the experimental plot is a high content of phosphorus (about 150-250 mg/kg), and an average content of potassium (80-120 mg/kg). This led to the abandonment of the main application of phosphate fertilizers. The soil is soddy-podzolic medium loamy. Agrochemical characteristics of the soil before laying the experiment: the content of organic matter - 3.7%, pHsol. -5.2, NH 4 - - traces, NO 3 - - 8 mg / kg, P 2 O 5 and K 2 O (according to Kirsanov) - 156 and 88 mg/kg, respectively, CaO - 1589 mg/kg, MgO - 474 mg/kg.
In the experiment with azofoska and rapeseed, the size of the experimental plot was 56 m 2 (14m x 4m), the repetition was four times. Pre-sowing tillage after the main fertilization - with a cultivator and immediately before sowing - with RBC (rotary harrow-cultivator). Sowing - with an Amazon seeder in optimal agrotechnical terms, seeding depth of 4-5 cm - for wheat and 1-3 cm - for rapeseed. Seeding rates: wheat - 200 kg/ha, rapeseed - 8 kg/ha.
In the experiment, spring wheat variety MIS and spring rapeseed variety Podmoskovny were used. The MIS variety is a highly productive mid-season variety that allows you to consistently obtain grain suitable for the production of pasta. The variety is resistant to lodging; much weaker than the standard is affected by brown rust, powdery mildew and hard smut.
Spring rapeseed Podmoskovny - mid-season, vegetation period 98 days. Ecologically plastic, characterized by uniform flowering and maturation, resistance to lodging 4.5-4.8 points. The low content of glucosinolates in the seeds allows the use of cake and meal in the diets of animals and poultry at higher rates.
The wheat crop was harvested in the phase of full grain ripeness. Rape was cut for green fodder in the flowering phase. Experiments for spring wheat and rapeseed were laid out according to the same scheme.
The analysis of soil and plants was carried out according to standard and generally accepted methods in agrochemistry.
Scheme of experiments with azofoska:
Background (50 kg a.i. N/ha for top dressing)
Background + azophoska main application 30 kg a.i. NPK/ha
Background + azophoska with humate main application 30 kg a.i. NPK/ha
Background + azophoska main application 60 kg a.i. NPK/ha
Background + azophoska with humate main application 60 kg a.i. NPK/ha
Background + azophoska main application 90 kg a.i. NPK/ha
Background + azophoska with humate main application 90 kg a.i. NPK/ha
During the years of research, the weather conditions differed significantly from the long-term average for the Non-Chernozem zone. In 2010, May and June were favorable for the development of agricultural crops, and generative organs were laid in plants with the prospect of a future grain yield of about 7 t/ha for spring wheat (as in 2009) and 3 t/ha for rapeseed. However, as in the entire Central region of the Russian Federation, a long drought was observed in the Moscow region from early July until the wheat harvest in early August. The average daily temperatures during this period were exceeded by 7 ° C, and daytime temperatures were above 35 ° C for a long time. Separate short-term precipitation fell in the form of heavy rains and water flowed down with surface runoff and evaporated, only partially absorbed into the soil. The saturation of the soil with moisture during short periods of rain did not exceed the penetration depth of 2-4 cm. In 2011, in the first ten days of May, after sowing and during plant germination, precipitation fell almost 4 times less (4 mm) than the weighted average long-term norm (15 mm).
The average daily air temperature during this period (13.9 o C) was significantly higher than the long-term average daily temperature (10.6 o C). The amount of precipitation and air temperature in the 2nd and 3rd decades of May did not differ significantly from the amount of average precipitation and average daily temperatures.
In June, the precipitation was much less than the average long-term norm, the air temperature exceeded the average daily by 2-4 o C.
July was hot and dry. In total, during the growing season, precipitation was 60 mm less than the norm, and the average daily air temperature was about 2 o C higher than the long-term average. Unfavorable weather conditions in 2010 and 2011 could not but affect the state of crops. The drought coincided with the grain filling phase of wheat, which ultimately led to a significant reduction in yield.
Prolonged air and soil drought in 2010 did not give the expected effect from increasing doses of azophoska. This has been shown in both wheat and rapeseed.
Moisture deficiency turned out to be the main obstacle in the implementation of the soil fertility, while the wheat yield was generally two times lower than in the similar experiment in 2009 (Garmash et al., 2011). Yield increases when applying 200, 400 and 600 kg/ha of azofoska (physical weight) were almost the same ( tab. 5).
The low yield of wheat is mainly due to the frailty of the grain. The mass of 1000 grains in all variants of the experiment was 27–28 grams. Data on the structure of the yield on the variants did not differ significantly. In the mass of the sheaf, the grain was about 30% (under normal weather conditions, this figure is up to 50%). The tillering coefficient is 1.1-1.2. The mass of grain in an ear was 0.7-0.8 grams.
At the same time, in the variants of the experiment with humated azofoska, a significant yield increase was obtained with an increase in fertilizer doses. This is due, first of all, to the better general condition of plants and the development of a more powerful root system when using humates against the background of the general stress of crops from long and prolonged drought.
A significant effect from the use of humated azofoska was manifested at the initial stage of development of rapeseed plants. After sowing rapeseed seeds, as a result of a short rainstorm followed by high air temperatures, a dense crust formed on the soil surface. Therefore, seedlings on the variants with the introduction of conventional azophoska were uneven and very sparse compared to the variants with humated azophoska, which led to significant differences in the yield of green mass ( tab. 6).
In the experiment with potash fertilizers, the area of the experimental plot was 225 m 2 (15 m x 15 m), the experiment was repeated four times, the location of the plots was randomized. The area of the experiment is 3600 m 2 . The experiment was carried out in the link of crop rotation winter cereals - spring cereals - busy fallow. The predecessor of spring wheat is winter triticale.
Fertilizers were applied manually at the rate of: nitrogen - 60, potassium - 120 kg of a.i. per ha. Ammonium nitrate was used as nitrogen fertilizers, and potassium chloride and the new KaliGum fertilizer were used as potash fertilizers. In the experiment, spring wheat variety Zlata, recommended for cultivation in the Central region, was grown. The variety is early maturing with a productivity potential of up to 6.5 t/ha. Resistant to lodging, much weaker than the standard variety is affected by leaf rust and powdery mildew, at the level of the standard variety - by septoria. Before sowing, the seeds were treated with the Vincit disinfectant in the norms recommended by the manufacturer. In the tillering phase, wheat crops were fertilized with ammonium nitrate at the rate of 30 kg of a.i. per 1 ha.
Scheme of experiments with potash fertilizers:
- Control (no fertilizer).
N60 basic + N30 top dressing
N60 basic + N30 top dressing + K 120 (KCl)
N60 basic + N30 top dressing + K 120 (KaliGum)
Thus, field experiments have reliably proven the agrochemical effectiveness of complex fertilizers with humate additives, determined by the increase in yield and protein content in grain crops. To ensure these results, it is necessary to correctly select a humic preparation with a high proportion of water-soluble humates, its form and place of introduction into the technological process at the final stages. This makes it possible to achieve a relatively low content of humates (0.2 - 0.5% wt.) in humated fertilizers and to ensure a uniform distribution of humates over the granule. At the same time, an important factor is the preservation of a high proportion of the water-soluble form of humates in humated fertilizers.
Complex fertilizers with humates increase the resistance of agricultural crops to adverse weather and climatic conditions, in particular, to drought and deterioration of soil structure. They can be recommended as effective agrochemicals in areas of risky farming, as well as when using intensive farming methods with several crops per year to maintain high soil fertility, in particular, in expanding zones with a water deficit and arid zones. The high agrochemical efficiency of the humated ammophoska (13:19:19) is determined by the complex action of the mineral and organic parts with an increase in the action of nutrients, primarily phosphorus nutrition of plants, an improvement in the metabolism between soil and plants, and an increase in plant stress resistance.
Levin Boris Vladimirovich – candidate of technical sciences, deputy general. Director, Director for Technical Policy of PhosAgro-Cherepovets JSC; e-mail:[email protected] .
Ozerov Sergey Alexandrovich - Head of Market Analysis and Sales Planning Department of PhosAgro-Cherepovets JSC; e-mail:[email protected] .
Garmash Grigory Alexandrovich - Head of the Laboratory of Analytical Research of the Federal State Budgetary Scientific Institution "Moscow Research Institute of Agriculture" Nemchinovka ", Candidate of Biological Sciences; e-mail:[email protected] .
Garmash Nina Yuryevna - Scientific Secretary of the Moscow Research Institute of Agriculture "Nemchinovka", Doctor of Biological Sciences; e-mail:[email protected] .
Latina Natalya Valerievna - General Director of Biomir 2000 LLC, Production Director of the Sakhalin Humat Group of Companies; e-mail:[email protected] .
Literature
Paul I. Fixsen The concept of increasing the productivity of agricultural crops and the efficiency of the use of nutrients by plants // Plant Nutrition: Bulletin of the International Institute of Plant Nutrition, 2010, No. 1. - With. 2-7.
Ivanova S.E., Loginova I.V., Tundell T. Phosphorus: mechanisms of losses from the soil and ways to reduce them // Plant Nutrition: Bulletin of the International Institute of Plant Nutrition, 2011, No. 2. - With. 9-12.
Aristarkhov A.N. et al. The effect of microfertilizers on productivity, protein harvest and product quality of grain and leguminous crops // Agrochemistry, 2010, No. 2. - With. 36-49.
Strapenyants R.A., Novikov A.I., Strebkov I.M., Shapiro L.Z., Kirikoy Ya.T. Modeling of the regularities of the action of mineral fertilizers on the crop. Vestnik s.-kh. Nauki, 1980, No. 12. - p. 34-43.
Fedoseev A.P. Weather and fertilizer efficiency. Leningrad: Gidrometizdat, 1985. - 144 p.
Yurkin S.N., Pimenov E.A., Makarov N.B. Influence of soil and climatic conditions and fertilizers on the consumption of the main nutrients in the wheat crop // Agrochemistry, 1978, No. 8. - P. 150-158.
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Fertilizers replenish the reserves of nutrients in the soil in an accessible form and supply them to plants. At the same time, they have a great influence on the properties of the soil and thus also affect the yield indirectly. By increasing the yield of plants and the mass of roots, fertilizers enhance the positive effect of plants on the soil, contribute to an increase in humus in it, and improve its chemical, water-air and biological properties. Organic fertilizers (manure, composts, green manure) have a great direct positive effect on all these soil properties.
Acidic mineral fertilizers, if they are systematically applied without organic fertilizers (and on acidic soils without lime), can have a negative effect on soil properties (Table 123). Long-term use of them on acidic non-lime soils leads to a decrease in soil saturation with bases, increases the content of toxic aluminum compounds and toxic microorganisms, worsens the water-physical properties of the soil, increases bulk density (density), reduces soil porosity, its aeration and water permeability. As a result of the deterioration of soil properties, the increase in yields from fertilizers is reduced, and the “hidden negative effect” of acid fertilizers on the crop is manifested.
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 effect of their bases on the absorbing complex of the soil. By displacing exchangeable hydrogen and aluminum, they convert the exchangeable acidity of the soil into active acidity and, at the same time, strongly acidify the soil solution, dispersing the colloids that hold the structure together and reducing its strength. Therefore, when applying large doses of mineral fertilizers, not only the acidity of the fertilizers themselves, but also the exchangeable acidity of the soil should be taken into account.
Lime neutralizes the acidity of the soil, 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 with bases, reduce acidity and sharply reduce the amount of toxic aluminum, which in acidic podzolic soils has an extremely strong negative effect on plant growth and yield.
In long-term experiments with the use of acidic mineral fertilizers on chernozems, a slight increase in soil acidity and a decrease in the amount of exchangeable bases are also noted (Table 124), which can be eliminated by introducing small amounts of lime.
Organic fertilizers have a great and always positive effect on all soils. Under the influence of organic fertilizers - manure, peat composts, green manure - the humus content increases, the saturation of the soil with bases, including calcium, improves the biological and physical properties of the soil (porosity, moisture capacity, water permeability), and in acidic soils, acidity, content toxic aluminum compounds and toxic microorganisms. However, a significant increase in the content of humus in the soil and an improvement in its physical properties are noted only with the systematic introduction of large doses of organic fertilizers. Their single application to acidic soils together with lime improves the qualitative group composition of humus, but does not lead to a noticeable increase in its percentage in the soil.
Similarly, peat introduced into the soil without prior composting does not have a noticeable positive effect on soil properties. Its influence on the soil increases dramatically if it is previously composted with manure, slurry, feces or mineral fertilizers, especially alkaline ones, since peat itself decomposes very slowly and in acidic soils forms many highly dispersed fulvic acids that support the acidic reaction of the environment.
The joint application of organic fertilizers with mineral fertilizers has a great positive effect on the soil. At the same time, the number and activity of nitrifying bacteria and bacteria that fix atmospheric nitrogen increase especially sharply - oligonitrophils, free-living nitrogen fixers, etc. In acidic podzolic soils, the number of microorganisms on the Aristovskaya medium decreases, which, in her opinion, produce a large amount of strong podzolizing the soil.
