The study of the dynamics of the content of nutrients in the soil when growing crops

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Introduction
In 2020-2022, the Krasnoyarsk Territory was the leader in Russia in the production of spring rapeseed [1][2][3].In 2021, the resulting crop of oilseeds amounted to 308.2 thousand tons.
In 2022, the area under crops under spring rapeseed was 204.5 thousand hectares, which is 14% more than in 2021.Spring rapeseed is a crop of versatile use, it is a reserve for increasing the production of oil and fodder protein, perfectly combining the potential productivity of seeds (up to 2.0 -4.0 t / ha) and green mass (25.0 -45.0 t / ha ).The protein content in the seeds of spring rape is from 18 to 23% with its optimal balance in terms of amino acid composition.The composition of rapeseed oil includes a large amount of unsaturated fatty acids (oleic, linolenic, linolenic), which are very necessary in human nutrition [4][5][6].Rapeseed oil with a low content of erucic acid is used for food purposes -to create oils, margarines, confectionery fats.In addition, a short growing season, significant cold resistance and the ability to tolerate short-term droughts make it possible to grow it in all soil and climatic zones of our Krasnoyarsk Territory.
The use of mineral fertilizers significantly increases the yield and increases the oil content of the seeds obtained.Fertilization is necessary only after a thorough soil diagnosis, at which the optimal dose will be calculated, allowing to increase the productivity of the crop and obtain high-quality oil seeds [7].
Rapeseed has a fairly high nitrogen requirement.The yield of seeds and the collection of fat strongly depend on the level of mineral nutrition of rapeseed.An average of 60 kg of nitrogen is spent on creating a ton of seeds and the corresponding amount of by-products.Nitrogen consumption by rapeseed depends on its varietal characteristics, the content of mineral nitrogen available to plants in the soil, the current mineralization of organic nitrogen during the growing season and doses of nitrogen fertilizers.Rapeseed is demanding on the level of nitrogen nutrition and the timing of application of nitrogen fertilizers.With their lack, plants acquire a light green and then yellow color, the leaves dry up and fall off, can turn yellow or orange-red with red veins, and the stem turns purple-red, the branches are underdeveloped.The overall need for the phases of plant growth and development is not the same.Excessive nitrogen nutrition of plants contributes to the accumulation of nitrates in products and delays the ripening of seeds [8].
Improving the phosphorus nutrition of spring rapeseed contributes to the formation of better seed formation, increased resistance to lodging and accelerated maturation.
Phosphorus has a positive effect on the ripening of spring rape seeds.It is this element that affects the number of seeds in the pods.Rape needs much more phosphorus than cereals.With a lack of this element, growth is inhibited at the beginning of the growing season, the leaves become dark green in color, later they become mauve along the edges, and with a significant deficiency of phosphorus, the entire leaf plate turns red.
Potassium is necessary for the formation of flowers and pods, as well as maintaining the water balance inside the plant.This nutrient increases the oil content of seeds, improves the resistance to lodging of crops, and increases the cold resistance of rapeseed.With the optimal content of potassium in the soil, the plants develop a powerful root system, the growth and development of the plant improves during the growing season.The lack of potassium primarily affects the development of plants -the color of the leaves becomes redbrown, the edges and tips of the leaf blades turn yellow.With a strong deficiency of this element, spring rapeseed plants may die [9].
Optimal doses of fertilizers can reduce the negative reaction of plants to the use of plant protection products and increase resistance to harmful organisms during the growing season [10].
The purpose of the research is to study the dynamics of the nutrient content in the soil when applying mineral fertilizers and plant protection products in the conditions of the Krasnoyarsk forest-steppe.

Materials and methods
On the territory of the station "Minino" the presence of the following types of soils was noted: gray forest soils, meadow -chernozem, meadow.However, the most widespread chernozems -leached and ordinary.They occupy the main area, all field experiments are laid on these soils.A characteristic feature of the soil cover of the lands of the experimental station is the widespread development of erosion processes.
The climatic conditions station Minino are characterized by a sharply continental climate.According to the Minino weather station, the average long-term air temperature is - In some years, when there is a shortage of moisture in the soil since autumn, and spring precipitation is not enough, spring-summer drought may occur.The weather conditions of the growing season of the studies were characterized by a lack of moisture.The minimum amount of precipitation fell in May and July (the amount of precipitation was below the long-term norm by 28.7 and 24.0 mm).The greatest amount of precipitation fell in August, the amount of precipitation in June was close to the average annual values.The total amount of precipitation during the growing season was 239.4 mm.
The warmest month was May -the average monthly temperature exceeded the longterm values by 3.6 o C. The average monthly temperature in June was close to the long-term values, the temperatures in July and August were less than the long-term values.
The spring rapeseed variety Nadeozhny 92 was used in the experiment.The originator variety Siberian Federal Research Center for Agrobiotechnology of the Russian Academy of Sciences.Variety type 00.The bush is semi-closed, 100.9 cm high.The pod is lemon yellow, without anthocyanin, unpeeled.The weight of 1000 seeds is 3.3 -4.1 g.The growing season before the seeds ripen is 93 -114 days.The fat content in seeds is 39.8 -47.6%, erucic acid in oil is 0.1 -1.5%.The protein content in the green mass is 10.1 -22.0%.Medium resistant to false powdery mildew, damaged by cruciferous fleas and rapeseed flower eater.
Sowing of spring rape seeds was carried out on May 20-22.Preparation of seeds for sowing provided for cleaning from weed impurities, determination of laboratory germination and pre-sowing etching according to the scheme of the experiment.Studied in the experiment: ammonium nitrate, ammophos, and azofoska were.The studied mineral fertilizers were applied with a seeder SZP-3,6.Sowing was carried out with a seeder CH-16 with a seeding rate of 3-4 million.w./ ha to a depth of 2-3 cm with rolling of crops.
The field experiment was based on leached chernozem, characterized by a low content of nitrate nitrogen (4.2 mg/100 g of soil), a mobile content of mobile phosphorus (185.0 mg/1000 g of soil) and a high content of mobile potassium (160.0 mg/1000 g of soil) -(Table 1).The selection of soil samples was carried out in phases in the phase of stalking, flowering and full ripeness.
The content of nitrate nitrogen was carried out according to GOST 26951-86, mobile compounds of phosphorus and potassium in accordance with GOST 26240-91.The scheme of the experience with the means of protection included the following options:  Control (without plant protection products);  Protection scheme I: imidocloprid-based seed treater, haloxifol-P-methyl and clopyralid herbicides, alpha-cypermethrin insecticide. Protection scheme II: seed treater based on thiamethoxam + mefenoxam + fludioxonil, herbicides based on haloxifol-R acid, clopyralide + picloram + aminopyralide, insecticide based on lambda-cyhalothrin.

Results and Discussion
During the growing season, the nitrate nitrogen content was low and did not exceed 3.3 mg/kg, the amount of nitrogen decreased by autumn.
The introduction of nitrogen mineral fertilizers allowed to significantly increase the content of nitrate nitrogen to an elevated and high level in June and July.The content of nitrate nitrogen sharply decreased in August -October due to the use of this element for crop formation (Table 1).
Рroviding of mobile phosphorus in the soil varied from medium (16.4 mg/100 g) to high (29.7 mg/100 g) availability.This is primarily due to the development of a pronounced meso-and microrelief, the shallow occurrence of soil-forming rocks, and economic activity (the development of erosion, the plowing of a low-humus soil horizon).On average, the degree of availability of mobile phosphorus can be characterized as increased according to generally accepted gradations (Table 3).When applying ammophos, there was a slight increase in the content of mobile phosphorus in the soil.Unlike nitrate nitrogen content, there was no sharp increase in the content of this element in the soil.This is primarily due to the increased phosphorus content in the soil.
The amount of mobile potassium in the studied soil varied from 10.0 to 17.5 mg/100 g of soil.The content of this element in the soil can be described as high (Table 4).The introduction of azophoska in N 80 P 80 K 80 background slightly increased the content of potassium in the soil, determined by the Chirikov method.The degree of soil availability with potassium on the N 80 P 80 K 80 background increases on average by one step of gradation in comparison with backgrounds without the use of potassium-containing fertilizer to a very high level.
The introduction of azofoski against the background of N 80 P 80 K 80 increased the amount of mobile potassium in the soil.The degree of potassium availability of the soil against the background of N 80 P 80 K 80 increases on average by one degree of gradation compared to backgrounds without the use of potassium-containing fertilizers to a very high level.

Conclusion
 The nitrate nitrogen content in the experiment variant without nitrogen fertilizers was very low (3.3 mg/kg of soil).The use of mineral fertilizers made it possible to increase the content of nitrate nitrogen to 25.2 mg / kg, which can be estimated as a very high level according to the generally accepted gradation, however, in July -August there was a decrease in the content of this element in the soil, which can be explained primarily by the costs of forming a seed crop. The content of mobile phosphorus determined by the Chirikov method varies from an average (16.4 mg/100 g) to a high (29.7 mg/100 g) degree of availability of this element.The introduction of phosphorus-containing fertilizers at a dose of P80 was characterized by a slight increase in the content of this element in the arable layer. The content of mobile potassium, determined by the Chirikov method, ranges from 10.0 to 17.5 mg / 100 g of soil.The availability of this element can be characterized as high according to the generally accepted gradation, the introduction of azofoski slightly increased the potassium content.

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011 (2023) BIO Web of Conferences CIBTA-II-2023 https://doi.org/10.1051/bioconf/2023710110707 71 C. The warmest month is July, the coldest is January.The period with an average daily air temperature above 0 o C begins in mid-April and lasts 180-190 days.The duration of the growing season is 122 days.The sum of active temperatures (+10 o C and more) is 1600-1800 o C. The average date of the first frost in autumn is September 18-20, the last spring frost is May 20-25.Krasnoyarsk forest-steppe belongs to a moderately dry zone.The annual precipitation is 370 mm, of which 60% falls during the growing season. o

Table 1 .
Gradation of soils by the content of nutrients.

Table 2 .
Nitrate nitrogen content during the growing season in spring rape sowing, N-NO 3 , mg/kg of soil.

Table 3 .
The content of mobile phosphorus during the growing season in the sowing of spring rape, P 2 O 5 , mg/100 g.

Table 4 .
The content of mobile potassium during the growing season in the sowing of spring rape, K 2 O 5 , mg/100 g.