Balance of nutrients in the soil

The balance of nutrients is a mathematical expression of the cycle of nutrients in agriculture. Determining the balance of nutrients is the scientific basis for planning and forecasting the use of mineral fertilizers, their distribution between regions and farms, allows you to purposefully regulate fertility, protect environment from contamination with fertilizers. The balance of basic nutrients reflects the degree of intensification of agricultural production.

The balance of nutrients in the “fertilizer-soil-plant” system is assessed by the difference between their total amount supplied to the soil and removed from it. Thus, the balance of nutrients in the soil consists of incoming and outgoing parts. IN credit side of the balance sheet admission included nutrients into the soilwith fertilizers, seeds, from atmosphere, including nitrogen, produced nodule bacteria legumes (symbiotic) and free-living bacteria - nitrogen fixers (non-symbiotic nitrogen). Expense part of the balance includes household takeout nutrients(with part of the harvest alienated from the field), loss of batteries from soil and fertilizers with surface water from leaching, erosion, evaporation and gaseous losses (nitrogen).

As a result of agricultural use, soils undergo significant changes, and the intensity of the processes of transformation and migration of nutrients, consumption and removal by plants changes. The amount of consumption and loss of nutrients depends on the granulometric composition and degree of cultivation of the soil, the nature of its agricultural use, the type, doses and timing of use of fertilizers, agricultural practices and other conditions. This makes it necessary to periodically clarify the incoming and outgoing items of the balance of batteries. To objectively characterize the degree of provision of planned crops with nutrients, it is advisable to have balance calculations for at least 5 years.

There are several types of nutrient balance: full(either biological or environmental), foreign economic, economic And effective.

Full balance gives a complete picture of the cycle of elements, since it takes into account all sources of nutrients entering the soil (with fertilizers, seeds, from the atmosphere, biological nitrogen) and all items of consumption of nutrients (removal with the main and by-products alienated from the field, content in root and post-harvest residues, surface runoff, leaching and gaseous losses).

At foreign economic balance the amount of nutrients alienated from the farm territory is compared with commercial products crop production and livestock farming, and their supply with mineral fertilizers, mixed feed, organic fertilizers purchased by the farm (peat, sapropels, lignin, peat-manure composts, etc.). The foreign economic balance is influenced by the specialization of the economy. Thus, in farms specializing in the production of livestock products and using their own feed, 80–90% of potassium, 60–70% of phosphorus and 40–50% of nitrogen carried out with feed are returned to the soil with organic fertilizers. In grain farms, 60–80% of nitrogen, 70–85% of phosphorus and 15–35% of potassium removed by the harvest are removed from the farm territory.

To characterize the balance, the indicator is used intensity balance–the ratio of the supply of batteries to their consumption. The intensity of the balance is expressed as a percentage or coefficients. A balance intensity value of less than 100% characterizes a deficit balance, 100% characterizes a deficit-free balance, and more than 100% characterizes a positive balance. Intensity of the balance of nitrogen, phosphorus and potassium on arable land in Belarus for 2001–2005. was for nitrogen - 116, phosphorus - 123, potassium - 127%.

A deficient balance of nutrients (excess of consumption over supply) warns that soil depletion and a decrease in their fertility are occurring.

The alienation of nitrogen, phosphorus and potassium from agricultural production with commercial crop and livestock products must be fully compensated by the application of mineral fertilizers.

Economic balance nutrients is compiled to evaluate the fertilizer application system. Let's give methodology its calculation, developed by the Institute of Soil Science and Agrochemistry. Incoming balance sheet items: supply of nutrients with mineral fertilizers; with organic fertilizers; symbiotic nitrogen; with seeds; with precipitation; non-symbiotic nitrogen. Balance sheet expense items nutrients: removal by planned harvests; losses from leaching (leaching); losses from soil erosion; gaseous nitrogen losses.

Quantity nutrients supplied With mineral fertilizers, determined by doses for crops and found average value per 1 hectare of crop rotation area. Arrival from organic fertilizers are found according to saturation of crop rotation with organic fertilizers.

Example. The saturation of organic fertilizers in crop rotation is 12 t/ha. From 1 ton of cattle manure on a straw bedding, 5.0 kg of nitrogen enters the soil (Table 14.11), and from 12 tons - 60.0 kg, phosphorus - 30.0 kg (2.5 ∙ 12), potassium - 72.0 kg (6.0 ∙ 12).

To determine the quantity biological nitrogen use data on the amounts of nitrogen fixed from the atmosphere remaining in the soil after legumes. Thus, per 1 centner of green mass, symbiotic nitrogen remains in the soil in excess of that absorbed by plants: after perennial leguminous grasses (except alfalfa) - 0.35 kg, alfalfa - 0.40, after perennial legume-cereal mixtures - 0.20 kg , after annual legume grasses - 0.25 kg, annual legume-cereal grass mixtures - 0.20 kg. Legume-cereal grasses of hayfields and pastures leave 0.15 kg of nitrogen in the soil per 1 centner of green mass. For 1 centner of grain, lupine in its pure form records 5.0 kg, broad beans - 3.0, peas, pellet, vetch, soybean in its pure form - 2.5, lupine mixed with grain crops - 4.5, peas, pellet and vetch mixed with grain crops - 2.0 kg of nitrogen.

14.11. Supply of nutrients with organic fertilizers, kg/t

View organic fertilizers	N	R 2 O 5	K 2 O	Sao	MgO	SO 4 *
Cattle manure on straw bedding	5,0	2,5	6,0	4,0	1,1	0,2
Cattle manure on peat bedding	6,0	2,0	5,0	4,5	1,0	0,5
Peat manure compost:
1:1	5,0	1,6	4,0	3,5	0,6	0,3
1:2	5,5	1,8	4,5	4,0	0,8	0,4
Straw (cereals)	4,0	1,5	10,0	2,0	1,0	1,5
Liquid cattle manure	2,0	1,0	2,5	0,5	0,4	0,1
Liquid pig manure	2,5	0,9	1,8	0,6	0,2	0,1
Semi-liquid cattle manure	3,5	1,5	4,0	1,3	0,9	0,3
Bird droppings (litter)	20,0	16,5	8,5	18,0	6,0	3,5
Peat manure compost:
1:1	10,0	8,0	3,0	9,0	3,0	1,5
1:2	12,5	10,0	4,0	10,0	4,0	2,0

*Values ​​are determined by calculation.

Example. In a crop rotation of 900 hectares, lupine occupies 100 hectares, clover - 100 hectares. The yield of green mass of lupine is 200 c/ha, clover (green mass) is 200 c/ha. After lupine, 50 kg of nitrogen (200∙0.25) remains in the soil per 1 ha, and 5000 kg per 100 ha. After clover, 70 kg of nitrogen remains per 1 hectare, and 7000 kg per 100 kg. The amount of nitrogen remaining after lupine and clover is divided by the area of ​​arable land in crop rotation and the average amount of symbiotic nitrogen per 1 ha is found: (5000 kg + 7000 kg): 900 = 13.3 kg.

WITH seeds, according to the Institute of Soil Science and Agrochemistry, on average 3 kg/ha of N, 1.3 – P 2 O 5, 1.5 – K 2 O, 0.3 – CaO, 0.1 – MgO, 0.2 kg/ ha S. C precipitation 9.4 kg/ha of N, 0.5 of P2O5, 10.3 of K2O, 25.3 of CaO, 5.0 of MgO and 36 kg/ha of S (SO4) are supplied. Admission nitrogen fixed by free-living bacteria when calculating the balance on arable and grassland lands, it is taken at the level of 15 kg/ha per year.

At calculation of expense items balance is first determined removal of nutrients by planned crops, using the data from table. 2.5, then the values ​​of the removal of basic nutrients on average per 1 hectare of crop rotation area are determined. Losses of nutrients from leaching (leaching) and soil erosion are given in Table. 14.12.

Gaseous nitrogen losses on arable and grassland ranges from 10 to 50% of that applied with fertilizers. Molecular nitrogen, nitrous oxide, nitrogen oxide and dioxide, and ammonia are released into the atmosphere. According to the Institute of Soil Science and Agrochemistry, in Belarus, on average, 25% of the nitrogen introduced with mineral and organic fertilizers evaporates. For each element, a weighted average loss rate is calculated taking into account the amount of eroded soil on the farm.

Example. Of the 2850 hectares of arable land on the farm, 201 hectares are slightly eroded soils, 105 hectares are moderately eroded and 98 hectares are highly eroded soils. The weighted average of nitrogen losses from erosion per 1 hectare of arable land will be equal to (5∙201+ +10∙105 + 15∙98) : 2850 = 1.2 (kg/ha). In hayfields and pastures, the loss of nutrients from leaching and erosion is not taken into account. The sum by expense items shows the consumption of nutrients on average per 1 hectare of crop rotation area.

14.12. Losses of nutrients from leaching and erosion on arable soils, kg/ha

Soils	N	R 2 O 5	K 2 O	Sao	MgO	SO 4
Washing losses
Sod-podzolic:
loamy		0,2
sandy loam on moraine		0,1
sandy loam on sand		0,1
sandy		0,1
Peat		0,1
Losses from erosion
Degree of soil erosion:
weak						0,05
average						0,10
strong						0,15
very strong						0,20

By comparing income with expenses, they find total balance and him intensity. For example, the nitrogen income per 1 ha is 115 kg, and the consumption is 90 kg, i.e. the total balance will be + 25 kg/ha (115–90), and the intensity of the balance will be 127% [(115:90) ∙ 100].

The overall balance of the main nutrients (nitrogen, phosphorus, potassium) is considered to be satisfactory when its intensity is approximately equal: for nitrogen - 110-120%, for phosphorus - 130-150, for potassium - 120-150%. According to the Institute of Soil Science and Agrochemistry, such values ​​of the balance intensity in production conditions ensure the productivity of arable land at the level of 50–60 c/ha.

The optimal values ​​of nitrogen balance intensity depending on the productivity of arable land are given in Table. 14.13.

14.13.Optimal intensity of nitrogen balance depending on productivity

Based on the results of long-term stationary field experiments, the Institute of Agrochemistry and Soil Science recommends optimal parameters for the intensity of the balance of phosphorus and potassium depending on their content in soils (Table 14.14). According to the Institute of Soil Science and Agrochemistry and other scientific institutions, phosphorus is practically not washed out from the soil and does not pollute groundwater. Therefore, when calculating the balance, phosphate losses are not taken into account.

14.14. Optimal balance intensity depending on soil availability

phosphorus and potassium

Along with the total, it is also calculated effective balance, which characterizes the relationship between the removal of nutrients by plants and their possible assimilation from those entering the soil. By applying the coefficients of use of nutrients from fertilizers, the values ​​of their possible absorption are found. By comparing the values ​​of the possible absorption of nutrients with the removal of crops, we obtain a characteristic of the effective balance.

Example. For 1 hectare of crop rotation area, 56 kg of nitrogen with mineral fertilizers was applied, 9 kg were added with precipitation, a total of 65 kg, of which 60% will be absorbed, i.e. 39 kg. Organic fertilizers will supply 70 kg of nitrogen and another 20 kg of biological (5 kg of symbiotic and 15 kg of non-symbiotic), a total of 90 kg/ha of nitrogen. In the first year, 25% of organic and biological nitrogen will be absorbed, or 22.5 kg (90 ∙ 0.25), together with mineral forms - 61.5 kg (39 + 22.5). Plants use 101 kg of nitrogen to create a crop. The effective balance is characterized by a minus value: 61.5–101.0 = –39.5 (kg/ha). The intensity of the effective nitrogen balance will be equal to 60% (61.5:101 ∙ 100).

Effective balances for phosphorus and potassium are calculated similarly.

To evaluate the fertilizer application system based on its effective balance, the possible absorption of nitrogen, phosphorus and potassium from soil reserves is calculated. The fertilizer application system can be considered correctly developed if the deficiency of nutrients in an effective balance is compensated for by possible absorption from the soil.

Example. To determine the possible absorption of nutrients from soil reserves, the weighted average values ​​of the content of humus, phosphorus and potassium in the soil according to crop rotation are preliminarily calculated. Let the soil contain 2% humus and 100 mg/kg of soil phosphorus and potassium. According to the Institute of Soil Science and Agrochemistry, plants can absorb 20–25 kg of nitrogen from soil reserves for each percentage of humus in the soil. In our example, this will be 40–50 kg/ha of nitrogen. Plants absorb phosphorus at a level of 6–8% of the reserves of mobile forms in the soil, potassium – 10–15%. Their reserves in the soil are determined by multiplying the weighted average values ​​of their content by a factor of 3. In our example, the reserves of phosphorus and potassium will be equal to 300 kg/ha (100 ∙ 3) of each element. Thus, 18–24 kg/ha of phosphorus (300 ∙ 0.06...0.08) and 30–45 kg/ha of potassium (300 ∙ 0.1...0.15) will be absorbed. If we accept the effective balance of the previous example as 39.5 kg of nitrogen, that is, 40–50 kg of nitrogen can be absorbed from the soil, then the planned yields will be provided with nutrients and the fertilizer system can be considered correctly developed.

When assessing the fertilizer application system based on the balance of nutrients, a change in the content of mobile forms of phosphorus and exchangeable potassium in the soil during crop rotation is predicted. The intake of phosphorus and potassium during crop rotation in excess of consumption is divided by the standard (Tables 14.15, 14.16) and the increase in their content in the soil is determined. The result is summed up with the original content and a forecast is obtained.

14.15. Cost standards for phosphorus fertilizers in excess of removal from the harvest to increase

Grading	pH KCl
Less than 60	61–100	101–150	151–250
Loamy	4,5–5,0
5,1–5,5
5,6–6,0
Sandy loam	4,5–5,0
5,1–5,5
5,6–6,0
Sandy	4,5–5,0
5,1–5,5
Peat	Average

14.16. Cost standards potash fertilizers beyond the yield with the harvest to increase

Grading	Balance intensity, %	Initial content of P 2 O 5, mg/kg of soil
Less than 80	81–140	141–200
Loamy
Sandy loam
Sandy
Peat		Average

Example. Let us assume that annually 65 kg/ha of P 2 O 5 remains in the soil in excess of what is removed by the crop, i.e. for nine-field crop rotation, 585 kg/ha of P 2 O 5 will be received. In the first 4 years, the content of P 2 O 5 in the soil increases to 147 mg/kg with an initial content on loamy soil of 100 mg/kg and a replacement standard of 51 kg/ha per 10 mg/kg of soil (Table 14.16). In the next 5 years, the compensation standard increases to 65 kg/ha and the content of P 2 O 5 in the soil increases by another 50 mg/kg, reaching 200 mg/kg of soil by the end of the crop rotation. Thus, after nine years the content of P 2 O 5 in the soil should be 197 mg/kg. The K2O content is predicted similarly.

Calculation of calcium, magnesium and sulfur balance. IN credit side of the balance sheet the supply of these elements from lime, organic And mineral fertilizers, and also with precipitation And seeds, consumables– removal by harvest And losses from filtration and erosion. The intake of calcium and magnesium with lime fertilizers is calculated by the amount of lime fertilizers per 1 ha. For example, on average, 1.1 tons of dolomite flour, or 0.935 tons of CaCO 3 (CaCO 3 content - 85%) will be applied annually per 1 hectare of crop rotation area. From the table 14.17 we find the amount of CaO and MgO per 1 ha, applied with lime fertilizers. With 935 kg of CaCO 3 comes 280.5 kg of CaO (30 ∙ 9.35) and 187 kg of MgO (20 ∙ 9.35).

per 100 kg a.i. (N, P 2 O 5, K 2 O, CaCO 3), kg

Fertilizers	Sao	MgO	S, %
Simple superphosphate		–
Double superphosphate		–	–
Ammonium sulfate	–	–	24,2
Potassium sulfate	–	–
Ground limestone		–	–
Ground dolomite			–
Ground dolomitized limestone		5,0	–
Chalk		–	–
Slaked lime		–	–
Dolomite flour			–
defect		–	–
Cement dust		1,0	1,0
Oil shale ash			–
Phosphogypsum (40% humidity, per 100 kg of physical mass)		–	17,7–20,6
Potassium sulfate			18,0
Magnesium sulfate			18,6
Sodium sulfate			22,6

According to the amount of mineral fertilizers per 1 hectare in d.v. determine the intake of CaO, MgO and S into the soil. For example, it is planned to apply 65 kg of P 2 O 5 in the form of double superphosphate per 1 hectare. With this amount of P 2 O 5 comes 20 kg of CaO (65 × 31/100). In the case of using ammonium sulfate and potassium sulfate, determine the amount of active substance supplied with these types of fertilizers per 1 ha, and calculate the sulfur intake using the data in table. 14.11.

Intake of calcium, magnesium and sulfur with organic fertilizers is calculated taking into account the saturation of the soil with the latter and the supply of these elements with fertilizers (see Table 14.11). For example, with a saturation of organic fertilizers in a crop rotation of 12 t/ha, the soil will receive 48 kg/ha CaO (4 × 12), 13.2 kg/ha MgO (1.1 × 12) and about 2.4 kg/ha SO 4 (0.2×12). With precipitation, 25.3 kg/ha of CaO, 3.6 of MgO, and 3.6 kg/ha of S enter the soil; with seeds, 0.3, respectively; 0.1 and 0.2 kg/ha. Summing up the results for the items of the income part of the balance, we obtain the supply of calcium, magnesium and sulfur per 1 hectare of crop rotation area.

Removal of calcium, magnesium and sulfur by the harvest are calculated in the same way as is done for nitrogen, phosphorus and calcium. Using the data given in table. 2.5, calculate the removal rates for each crop and calculate the average values ​​per 1 ha. Losses from leaching and erosion are found from table. 14.12.

When liming, calcium loss due to leaching increases, especially on light soils. According to the Institute of Soil Science and Agrochemistry, on soils with a pH (KC1) of more than 6, calcium loss increases by an average of 40% compared to the average data on soils without liming. On acidic soils(pH less than 5) calcium leaching is approximately 20% lower. Therefore, when calculating the calcium balance, the average standard loss indicator (Table 14.12) on soils with a pH of more than 6 should be multiplied by 1.4, and on soils with a pH of less than 5 by 0.8.

The effect of liming on the leaching of magnesium is ambiguous, since in some cases calcium cations accelerate its leaching from the soil, which is due to the displacement of magnesium from the absorbing complex, and in others they can reduce the leaching of magnesium by neutralizing the acidity of the soil, which contributes to the loss of magnesium due to leaching. In this regard, when calculating the magnesium balance, the standards for losses from leaching given in table are used. 14.12. Determine the consumption per 1 ha.

By comparing the income and expense indicators, the balance values ​​and its intensity are found.

QUESTIONS FOR SELF-CONTROL

1. What is meant by the balance of nutrients in the soil?

2. What is the importance of the balance of nutrients in the soil for regulating soil fertility and crop yields?

3. How to evaluate the system of using fertilizers in crop rotation based on the balance of nutrients?

4. What are the different types of battery balance?

5. How can we predict changes in soil fertility based on the balance of nutrients in it?

INTRODUCTION

Expanded reproduction of potential and effective soil fertility is the initial condition for ensuring continuous growth in crop yields, which is possible with a positive balance of nutrients and organic matter soils in reclamation agriculture. In natural biocenoses a closed cycle of nutrients is achieved, and in artificial agrocenoses this cycle is broken due to alienation for harvesting and significant losses of nutrients due to erosion, infiltration and volatilization. Creation necessary conditions for rational circulation nutrients- the most important task of irrigated agriculture. It is possible to positively influence effective soil fertility, which is understood as the provision of soil with available nitrogen and phosphorus, as well as exchangeable potassium, and obtain planned yields of irrigated crops by carrying out balance calculations, while creating, by applying calculated doses of fertilizers, the optimal level of humus content and mobile forms of nutrients elements in the soil.

CALCULATION OF NUTRIENT BALANCE

Nutrient balance- this is a quantitative expression of the content of nutrients in the soil in a specific area, taking into account all items of their input (fertilizer application, natural sources, nitrogen fixation, etc.) and consumption (removal with the harvest, natural losses due to leaching, flushing, volatilization, etc.) during a certain period of time. Imbalance of nutrients in agriculture can worsen chemical composition soil, natural waters, and, consequently, plants. This in turn can change the quality and nutritional value of agricultural products and animal feed and lead to functional diseases humans and animals.

Therefore, it is important to properly manage the cycle of nutrients in agriculture, create their active balance by using organic and mineral fertilizers, and prevent their loss into the environment. This is one of the most important tasks in the creation and application of landscape-adaptive systems of reclamation agriculture.

Nitrogen balance

Of particular interest is the balance of nitrogen - the main carrier of life, an element that determines the quantity and quality of the crop. The problem of nitrogen in agriculture is very relevant. This is explained by the fact that nitrogen is a very mobile element and does not accumulate in the soil. Therefore, with an increase in the content of other nutrients, soil fertility and its cultivation in general, nitrogen will determine the size and quality of the crop. When calculating the nitrogen balance, only the main income and expense items are taken into account, including the supply of nitrogen with mineral, organic fertilizers and biological fixation by nodule bacteria, and the removal of nitrogen with the harvest of the main and by-products. Nitrogen balance equation:

Where B a– balance of available nitrogen, kg/ha; U D min– doses of mineral nitrogen-containing fertilizers in fertilizers, kg/ha; Dorg CA min– nitrogen content in mineral fertilizer (Appendix 4),%; CA org– nitrogen content in organic fertilizer (Appendix 5),%; In a– nitrogen removal from the harvest of main and by-products (Appendix 1), kg/t; AF– biological fixation of nitrogen by nodule bacteria of legumes, kg/t (assumed to be equal to 10 kg/t of legume grass hay, 0.5 kg/t of green fodder of cereal legume grass mixtures, 26 kg/t of soybean grain).

Example of nitrogen balance calculation.

Solution: The nitrogen content in manure is 0.45%, sulfoammophos 12%; removal with a yield of 3.5 kg/t. There is no nitrogen fixation in corn ( AF =0).

Kg/ha. The balance is in deficit.

Phosphorus balance

Although living organisms require approximately 10 times less phosphorus than nitrogen, it is nevertheless the most important biogenic element. Phosphorus is not only a source of nutrition for plants, but also an energy carrier, which is part of various nucleic acids. Phosphorus deficiency sharply reduces plant productivity. Phosphorus has no natural sources of replenishment in the soil. It is possible to replenish its consumption to create crops only by applying phosphorus and organic fertilizers. In the future, the problem of phosphorus as a biogenic element in agriculture arises first. Phosphorus is found in the atmosphere mainly in the form of dust in small quantities. Its cycle is simpler than the nitrogen cycle. In ecosystems, only soil, water and plants are involved. The availability of this element to plants is influenced by many environmental factors, so the problem of phosphorus as a biogenic element in agriculture arises first. The phosphorus balance is calculated using the formula:

Where B f– balance of available phosphorus, kg/ha; U– productivity of the cultivated crop, t/ha; D min– doses of mineral phosphorus-containing fertilizers in fertilizers, kg/ha; Dorg– doses of organic fertilizers, t/ha; SF min– phosphorus content in mineral fertilizer (Appendix 4),%; SF org– phosphorus content in organic fertilizer (Appendix 5),%; V f

An example of calculating the phosphorus balance. When cultivating silage corn, 30 tons of cattle manure on straw bedding and 150 kilograms of sulfoammophos per hectare were applied. As a result, 60 t/ha of silage was obtained.

Solution: The phosphorus content in manure is 0.23%, sulfoammophos is 39%; removal with a yield of 1.4 kg/t. kg/ha. The balance is positive.

Potassium balance

Potassium is found mainly in the fine mineral part of the soil. Its deficiency in the soil sharply inhibits the growth and development of plants. Being in them in the form of the K + cation, it regulates important physiological processes, ensuring moisture exchange in plant cells and maintaining high cytoplasmic activity. The potassium balance equation is:

Where B to– balance of available potassium, kg/ha; U– productivity of the cultivated crop, t/ha; D min– doses of mineral potassium-containing fertilizers in fertilizers, kg/ha; Dorg– doses of organic fertilizers, t/ha; CK min– potassium content in mineral fertilizer (Appendix 4),%; SK org– potassium content in organic fertilizer (Appendix 5),%; VC– removal of phosphorus with the harvest of main and by-products (Appendix 1), kg/t.

An example of calculating potassium balance. When cultivating winter wheat, 20 tons of cattle manure on straw bedding, 60 kilograms of potassium chloride and 120 kilograms of carboammophoska per hectare were applied. As a result, 4.0 t/ha of grain was obtained.

Solution: The potassium content in manure is 0.5%, potassium chloride 53%, karboammofoska 17%; removal with a yield of 36 kg/t.

Kg/ha. The balance is deficit-free.

CALCULATION OF HUMUS BALANCE

Several multidirectional processes associated with decomposition (mineralization) and formation (humification) of humus occur simultaneously in the soil. For the targeted regulation of humus reserves in the studied soils, the humus balance is calculated based on the information obtained about its content and reserves in the soils of the studied area and data on productivity. The humus balance equation has the form:

Where B g – humus balance, t/ha; Y – yield, t/ha; In a– nitrogen removal per 1 ton of crop, kg/t (Appendix 1); P P And P K– supply of crop and root residues, respectively, t/ha; K GR and K GU – humification coefficients of plant residues and organic fertilizers, respectively (Appendix 3); Dorg– dose of organic fertilizer, t/ha; %VL– moisture content of organic fertilizer, % (Appendix 5).

The supply of crop and root residues is determined using their regression dependencies on the crop yield (Appendix 2).

An example of calculating humus balance. When cultivating potatoes, 150 tons of cattle slurry were applied per hectare. As a result, 24 t/ha of potato tubers were obtained.

Solution: Receipt of crop residues: P P = 0,04∙24+0,1=1,06 t/ha. Intake of root residues: P to = 0,08∙24+0,8 = 1,536 t/ha. The humification coefficient of residues is 0.35, cattle manure is 0.35.

t/ha. Balance is scarce.

Change in humus content

The calculation of the initial reserves of humus in the upper 30-centimeter layer is carried out taking into account the density of the soil according to the formula:

, (5)

Where ZG 0– initial reserves of humus in the upper 30 cm layer, t/ha; ρ sl– soil density (Appendix 6), g/cm 3 ; SG 0– initial humus content (Appendix 6), %.

The predicted humus content (%) is determined by the formula:

, (6)

The obtained value is compared with the range of background humus content (Appendix 7). In addition, the absolute and relative change in humus content is determined:

, (7)

, (8)

As a result, a conclusion is drawn about the significance of the changes.

An example of assessing changes in humus content. As a result of calculating the humus balance, it was determined that reserves would decrease by 36 t/ha. The soil of the irrigated area is chestnut medium loamy with an initial humus content of 2.2%. Determine the content change and its significance.

The density of the top layer of soil is 1.22 g/cm 3 . t/ha. %.

This value is outside the fluctuation range of 1.8-3.0 (Appendix 8). The absolute and relative changes in content are also very high: ; , which indicates an unacceptably deficient balance of soil organic matter.

Description of execution.

1. Launch Microsoft Excel .

A" And " INA"2-3 times.

3. In cell " A2» enter the word “Culture”, and in the cells “ A3»- « A12» names of crop rotation crops from your option.

4. In cell " AT 2"enter the word "Yield", and in the cells " AT 3»- « AT 12» crop rotation yields from your option.

5. In cell " D1"enter the word "Takeaway" in the cells " C2" - "nitrogen"; " D2" - "phosphorus"; " E2" - "potassium".

6. In cell " F1"enter the word "Losses" in the cell " F2- “humus”.

7. In cells " C3»–« C12» enter formulas to calculate nitrogen removal. To do this, point the cursor at the cell “ C3"enter in the formula bar "=B3*(xx-yy)", where xx is the value of nitrogen removal for a given crop (Appendix 1); yy is the biological fixation of nitrogen by nodule bacteria of legumes, kg/t (taken equal to 10 kg/t of legume grass hay, 0.5 kg/t of green fodder of cereal legume grass mixtures, 26 kg/t of soybean grain). Repeat the operations for the cells " C4»–« C12».

8. Enter in the cells " D3»–« D12"formulas for calculating phosphorus removal "=B3*xx", where xx is the value of phosphorus removal for a given crop (Appendix 1), and in cells " E3»–« E12» similar formulas for calculating potassium removal.

9. In cells " F3»–« F12» calculate the loss of humus. To do this, according to the formula given earlier, divide the removal of nitrogen without taking into account the biological fixation of nitrogen by nodule bacteria by 50. The formula in the cell “ F3" will have the form: "=B3*xx/50", where xx is the value of nitrogen removal for a given crop (Appendix 1).

10. In cell " H1"enter the word "Remainings" in the cells " G2» – “stubble”; " H2» – “root”; " I2" - "sum".

11. In cells " G3»–« G12» calculate the supply of crop residues. To do this, enter in them the formulas for regression dependences of the mass of crop residues on crop yields (Appendix 2), replacing “x” with a link to the corresponding cell from the yield column (cells “ B3»–« B12»).

12. Similarly, calculate in cells “ H3»–« H12» supply of root residues.

13. Sum in cells " I3"–"I12» crop and root residues ( =G3+H3).

14. In cell " J2" enter "Kg" and cells " J3"–"J12» values ​​of humification coefficients of plant residues from Appendix 3.

15. In cell " K1"Enter the word "Receipt" in the cell " K2- “humus”.

16. In cells " K3»–« K12» calculate the humus intake by multiplying the humification coefficient by the sum of plant residues (columns G And TO).

17. In cell " L2"enter "Bg", and in the cells " L3"–"L12» humus balances ( =K3-F3).

18. In cell " C13» calculate the total nitrogen removal for the entire rotation. To do this, point the cursor at this cell, click the “Insert Function” button (), and select “SUM” from the list of functions. In the "Function Arguments" window that opens, specify the icon for entering the range of cells to sum () and circle the cells with the cursor " C3»–« C12" Press Enter to confirm and then OK.

19. Extending the resulting formula to the cells “ D13" And " E13» You will receive the total removal of phosphorus and potassium.

20. To calculate the humus balance without the participation of fertilizers, repeat the operations from point 18 for cell “ L13" and range " L2-L12».

21. Enter in the cell " A16"Fertilizer", in cell " B16"Dose", in cell " D15" "Content"; into cells " C16», « D16», « E16», « F16" - "Nitrogen", "Phosphorus", "Potassium", "water".

22. In cells " A17-A22» enter the names of the applied fertilizers (first organic, then mineral).

23. In cells " B17-B22» enter the doses of fertilizers applied, for organic fertilizers in tons per hectare, for mineral fertilizers - kilograms per hectare.

24. In cells " S17-S22» enter the nitrogen content of fertilizers, « D17-D22" - phosphorus, " E17-E22" - potassium, " F17-F22» - water (Appendices 4, 5).

25. Enter in the cell " H15""Receipt", and in the cells " G16», « H16», « I16» copy the contents of the cells « C16», « D16», « E16».

26. Calculate the supply of nutrients from organic fertilizers. To do this, in the cell " G17"enter the formula "=$B17*C17*10". The “$” sign means that when the formula is extended, column “B” in it will not change, and the coefficient 10 is obtained by dividing 1000 (kilograms per ton) by 100 (percent).

27. Extend the formula to the organic fertilizer rows and the “ D" And " E».

28. Calculate the supply of nutrients with mineral fertilizers. To do this, enter the formula “=$B19*C19/100” in the cell at the intersection of the first row with mineral fertilizers and column “G”.

29. Extend the formula to rows with mineral fertilizers and columns “ D" And " E».

30. Sum up the intake of nitrogen, phosphorus and potassium in the cells " G23», « H23», « I23"(similar to paragraph 18).

31. Enter in the cell " J16"organics", into cell " K16"humus."

32. Enter in the cell " J17"Formula for calculating the supply of fresh organic matter to the soil: "=B17*(1-F17/100)". Apply it to all rows with organic fertilizers.

33. Enter in the cell " K17"Formula for calculating the entry of humus into the soil: "=J17*0.35" (0.35 is the humification coefficient of plant residues from Appendix 3). Apply the formula to all rows with organic fertilizers.

34. Sum in cell " K23» the entry of humus into the soil is similar to points 18 and 30.

35. Enter in the cells " A24-A28» the words “Balance”, “humus”, “nitrogen”, “phosphorus”, “potassium”.

36. In cell " A25» calculate the humus balance (“=L13+K23”); in cells " A26-A28» balances of nitrogen, phosphorus and potassium using the formulas “=G23-C13”, “=H23-D13” and “=I23-E13” respectively.

37. Save the Microsoft Excel workbook (file) with the name your teacher gives you. Turn off Microsoft Excel.

Description of execution.

1. Launch Microsoft Excel.

2. Open a file (book Microsoft Excel) created during Exercise 1.

3. Copy the results of the balance calculation to another sheet of the book.

4. To do this, circle the cells “ A24-B28"; copy their contents to the clipboard (for example, by clicking " Ctrl+C"); go to the desired sheet (list of sheets at the bottom of the table); select from the main menu " Edit» – « Special insert", and in the Paste Special window that opens, mark the value indicator.

5. Enter in the cell " C1» “Initial inventories”, in cell “ D1» “Ending inventory.”

6. Enter in the cell " C2» formula for calculating the initial reserves of humus “=30*хх*yy”, where хх is the soil density (Appendix 6), g/cm 3 ; yy – initial humus content (Appendix 6),%.

7. In cell " D2"enter the formula for calculating the final (predicted) humus reserves "=B2+C2".

8. Enter in the cell " E1"Content forecast", and in cell " E2"formula for calculating the humus content in%: "=D2/30/xx", where xx is the soil density (Appendix 6), g/cm3.

9. Enter in the cells " F1" And " G1» “Absolute change” and “Relative change”

10. In cell " F2"enter the formula for calculating the absolute change in humus content "=C2-D2".

11. In cell " G2"enter the formula for calculating the relative change in humus content "=F2/C2*100".

12. Enter in the cells " C4" And " C5» formulas for calculating the initial reserves of available phosphorus and exchangeable potassium in the upper 30-centimeter layer “30*хх*yy1” and “30*хх*yy2”, where хх is the soil density (Appendix 6), g/cm 3 ; yy1 and yy2 – initial content of available phosphorus and exchangeable potassium, mg per 100 g of soil (Appendix 6).

13. Enter in the cells " D4" And " D5"formulas for calculating the predicted reserves of available phosphorus and exchangeable potassium "=C4+B4" and "=C5+B5".

14. In cells " E4" And " E5"enter formulas for calculating the predicted content of phosphorus and potassium "=D4/30/xx" and "=D5/30/xx", where xx is the soil density (Appendix 6), g/cm3.

15. In cells " G4" And " G5"calculate the relative change in the content of available phosphorus and potassium (formulas "(yy1-E4)/yy1*100" and "(yy2-E5)/yy2*100", where the initial content of available phosphorus and exchangeable potassium, mg per 100 g of soil) .

Description of execution.

1. Launch Microsoft Excel.

2. Pointing the mouse cursor at the border between the columns " A" And " IN" in the line with the column names, click the left mouse button and expand the column " A"2 times. Repeat the operation for the column " IN».

3. In cell " AT 2» enter the word “Content”, and in the cells « A3», « A5», « A6», « A7- “humus”, “nitrogen”, “phosphorus” and “potassium”.

4. In cell " AT 3"enter the humus content in the cell " AT 6"phosphorus, and into the cell " AT 7» potassium from your option.

5. In cell " C3» enter “Coverage share =”, and in the cell “ D3» the value of the share of covering the need for nitrogen with organic fertilizers from Appendix 11.

6. In cell " C4"enter "Xmin" in the cell " D4" - "Xmax", in cell " E4" - "Kmin", in cell " F4" - "Kmax", in cell " G4" - "K".

7. Enter in the cells " C6" And " C7» lower limits of the intervals in which the values ​​of phosphorus and potassium content fall (Appendix 8).

8. Enter in the cells " D6" And " D7» upper limits of the intervals in which the values ​​of phosphorus and potassium content fall (Appendix 8).

9. Enter in the cells " E6" And " E7» the lowest values ​​of rotational balance coefficients for the intervals in which the phosphorus and potassium content values ​​fall (Appendix 9).

10. Enter in the cells " F6" And " F7» highest values rotational balance coefficients for the intervals in which the phosphorus and potassium content values ​​fall (Appendix 9).

11. Enter in the cell " G5» value of the rotational balance coefficient for nitrogen (1).

12. In cells " G6" And " G7» enter formulas for calculating the rotational balance coefficients for phosphorus and potassium (formula 18).

13. In cell " G5» enter the rotational balance coefficient for nitrogen – 1.

14. In cells " A9" And " AT 9» enter the words “Culture” and “Yield”.

15. In cells " A10» – « A13» enter the names of the crops from your version of the task; into cells " AT 10» – « B13- their productivity.

16. Enter in the cells " C9», « D9», « E9" And " F9» designations “AF”, “VA”, “VF” and “VK” (nitrogen fixation, nitrogen removal, phosphorus removal, potassium removal).

17. In cells " C10» – « F13» enter the values ​​of nitrogen fixation (note to formula 1) and removal of nutrients for all crops (Appendix 1).

18. Enter in the cell " A15"the word "Fertilizer", and in the cells " B15», « C15" And " D15» designations “Ca”, “Sph” and “Sk” (content of nitrogen, phosphorus, potassium).

19. In cells " A16» – « A19» enter the names of fertilizers from your task option; into cells " B16» – « D19» – content of batteries in them (Appendices 4 and 5).

20. Copy " D9», « E9" And " F9» into cells « G9», « H9», « I9».

21. In cells " G10» – « G13» calculate the removal of nitrogen from the crop yield (formula for line 10: “=B10*(D10-C10)”).

22. In cells " H10» – « H13" And " I10» – « I13» calculate the removal of phosphorus and potassium with the crop (formula for phosphorus and line 10: “=B10*E10”; potassium and line 10: “=B10*F10”).

23. Enter in the cells " J9», « K9», « L9» designations “Doa”, “Dof” and “Dok” (total doses of fertilizers for each main nutrient in kilograms of active substance).

24. In cells " J10» – « L13» calculate the total doses of fertilizers for each main nutrient (for example, for « J10" – "=G10*$G$5").

25. In cell " M9" enter the designation "Dorga" (dose of organic nitrogen), and in the cells " M10» – « M13"Calculate this dose using formula 19.

26. In cell " N9"enter the designation "Dorg" (dose of organic fertilizer), and in the cells " N10» – « N13"Calculate this dose using formula 20.

27. In cell " O9"enter the designation "Dorgo" (rounded dose of organic fertilizer), and in the cells " O10» – « O13» – doses of organic matter for each crop, rounded to 5 t/ha.

28. Enter in the cells " P9», « Q9», « R9» designations “Dorga”, “Dorgf” and “Dorgk” (kilograms of active substance for each main nutrient contained in organic fertilizer).

29. Calculate the doses of nutrients in organic fertilizer. To do this, enter in the cell " P10" formula "=10*$O10*B$16" and then extend it to the cells " P10» – « R13».

30. Enter in the cells " S9», « T9», « U9» designations “Dma”, “Dmf” and “Dmk” (kilograms of active substance for each main nutrient that must be added with mineral fertilizer).

31. In cells " S10» – « U13"Define these doses as the difference between the total need for the nutrient and its content in the organic fertilizer. To do this, enter in the cell " S10"formula =J10-P10" and then extend it to the cells " S10» – « U13».

32. Enter in the cells " V9», « W9», « X9» designations “MA”, “MF” and “MK” (doses of nitrogen, phosphorus and potassium mineral fertilizers in natural fertilizers, kg).

33. In cells " V10» – « X13“Determine these doses using formulas: for nitrogen fertilizer – “=S10*100/B$17”; phosphorus – “=T10*100/C$18”; potassium – “=U10*100/D$19”.

34. Label cells " V10» – « X14" and round them to whole numbers (menu items "Format" - "Cells" - "Number"). In the window that opens, select the “Numeric” format and specify the number of decimal places – 0.

35. In cells " O14», « V14», « W14», « X14"Using the "SUM" function, calculate the total doses of fertilizers.

LITERATURE

1. Kravchuk A.V., Muravlev A.P., Prokopets R.V., Donguzov G.S. Fundamentals of rational environmental management: guidelines and materials for laboratory and practical classes. – Saratov: Saratov State Agrarian University named after N.I. Vavilova, 2004. – 47 p.

2. Kravchuk A.V., Shavrin D.I., Prokopets R.V. Guidelines on implementation course work in the discipline "Environmental Management" - Saratov: Federal State Educational Institution of Higher Professional Education "Saratov State Agrarian University named after N.I. Vavilova”, 2013. – 20 p.

3. Leontyev S.A., Chumakova L.N., Prokopets R.V., Arzhanukhina E.V., Nikishanov A.N. Natural-technogenic complexes of environmental management: guidelines for the implementation of the course project - Saratov: Federal State Educational Institution of Higher Professional Education "Saratov State Agrarian University named after N.I. Vavilova”, 2012. – 40 p.

4. Prokopets R.V. The influence of irrigation erosion on the loss of nutrients in the soil // Problems of scientific support of agricultural production and education: collection of articles. scientific works - under the general editorship of A.V. Kravchuk. – Saratov, 2008. – P. 183-188.

5. Prokopets R.V. Removal of nutrients with surface runoff on dark chestnut soils during irrigation of eastern goat's rue // Vavilov Readings 2006: Proceedings of the conference dedicated to the 119th anniversary of the birth of Academician N.I. Vavilova. – Saratov: Federal State Educational Institution of Higher Professional Education “Saratov State Agrarian University named after. N.I. Vavilova”, 2006. – pp. 72-73.

6. Prokopets R.V. Removal of nutrients from solid waste on dark chestnut soils with irrigation of eastern goat's rue // Systematic studies of natural-technogenic complexes Lower Volga region: Sat. scientific works – Saratov, 2007. – pp. 124-127.

7. Prokopets R.V., Arzhanukhina E.V., Shavrin D.I., Zavadsky I.S. Planning of environmental measures: guidelines for the implementation of calculation and graphic work - Saratov: Federal State Educational Institution of Higher Professional Education "Saratov State Agrarian University named after N.I. Vavilova”, 2012. – 29 p.

8. Prokopets R.V., Chumakova L.N., Arzhanukhina E.V., Shavrin D.I., Zavadsky I.S. Management of reclamation water systems using computer technologies: guidelines for implementation laboratory work. – Saratov: Federal State Educational Institution of Higher Professional Education “Saratov State Agrarian University named after N.I. Vavilova”, 2012. – 26 p.

9. Pronko V.V., Korsak V.V., Druzhkin A.F. The influence of weather conditions and agrotechnical practices on the efficiency of fertilizers in the steppe Volga region // Agrochemistry, 2004, No. 8, pp. 20-26.

10. Pronko N.A., Korsak V.V. Method for calculating doses of organic and mineral fertilizers for crops in irrigated crop rotations based on the forecast rotational balance of nutrients // Agrochemistry, 2001, No. 7, pp. 66-71.

11. Pronko N.A., Korsak V.V., Korneva T.V. Features of dehumification of irrigated dark chestnut soils of the Saratov Trans-Volga region // Bulletin of the Saratov State Agrarian University named after. N.I. Vavilova. – 2009. – No. 10. – P. 42-46.

12. Pronko N.A., Korsak V.V., Prokopets R.V., Korneva T.V., Romanova L.G. Calculation of balances of humus and plant nutrients in reclamation agriculture using information technologies/ Guidelines for completing coursework and laboratory practical work. – Saratov, Federal State Educational Institution of Higher Professional Education “Saratov State Agrarian University”, 2010, 39 p.

13. Pronko N.A., Korsak V.V., Falkovich A.S. Irrigation in the Volga region: do not repeat mistakes. – Melioration and water management, 2014, No. 4, pp. 16-19.

14. Pronko N.A., Falkovich A.S., Romanova L.G. Changes in the fertility of irrigated chestnut soils in the Volga region during long-term use and the scientific basis for its regulation. – Saratov: SSAU, 2005, 220 p.

APPLICATIONS

№	Name	Element content, %
nitrogen	phosphorus	potassium
	Sodium nitrate	16,3	0,0	0,0
	Ammonia liquid	82,0	0,0	0,0
	Ammonia water	16,0	0,0	0,0
	Ammonium sulfate	20,8	0,0	0,0
	Ammonium nitrate	34,0	0,0	0,0
	Urea (carbamide)	46,0	0,0	0,0
	Granulated superphosphate	0,0	20,5	0,0
	Double granulated superphosphate	0,0	49,0	0,0
	Potassium chloride	0,0	0,0	53,0
	Mixed potassium salt	0,0	0,0	40,0
	Potassium magnesium sulfate (potassium magnesium)	0,0	0,0	28,0
	Ammophos, grade A, premium	12,0	52,0	0,0
	Ammophos, grade A, first grade	12,0	50,0	0,0
	Ammophos, grade B, premium	11,0	44,0	0,0
	Ammophos, brand B, first grade	10,0	42,0	0,0
	Sulfoammophos	12,0	39,0	0,0
	Nitrofoska, grade A	16,0	16,0	16,0
	Nitrofoska, grade B	12,5	8,0	12,5
	Nitrofoska, grade B	11,0	10,0	11,0
	Nitrophos, grade A	23,0	17,0	0,0
	Nitrofos, grade B	24,0	14,0	0,0
	Nitroammophos, grade A	23,0	23,0	0,0
	Nitroammophos, grade B	16,0	24,0	0,0
	Nitroammophos, grade B	25,0	20,0	0,0
	Nitroammophoska	13,0	19,0	19,0
	Karboammofoska	17,0	17,0	17,0
	Liquid complex fertilizers	10,0	34,0	0,0

№	Name	Content, %
nitrogen	phosphorus	potassium	water
	Cattle manure on straw bedding	0,45	0,23	0,50	77,30
	Pig manure on a straw bed	0,45	0,19	0,60	72,40
	Horse manure on straw bedding	0,58	0,28	0,63	64,60
	Manure mixed on straw bedding	0,50	0,25	0,60	71,30
	Slurry (cattle)	0,26	0,12	0,38	98,80
	Slurry (pork)	0,31	0,06	0,36	98,80
	Slurry (horse)	0,39	0,08	0,58	98,80
	Bird droppings	0,90	1,70	0,90	56,00

6. Soil density, humus content and available nutrients in the upper 30 cm layer

№	Soil type	Density, t/m 3	Humus content, %	Content, mg/100 g soil
phosphorus	potassium
	Southern low-humus chernozem	1,15	3,6	5,1
		1,20	5,4	9,2
	Southern medium loamy chernozem	1,22	4,7	5,5
	Dark-	1,14	2,8	4,2
	Dark chestnut heavy loamy	1,28	3,6	7,0
	Chestnut medium loamy	1,22	2,9	4,8
	Light chestnut heavy loamy	1,30	2,4	3,8
	Light chestnut light loamy	1,35	1,8	4,1

Options for initial data for calculating the balance and changes in the content of humus and nutrients

	Cultures	Productivity, t/ha	Fertilizer application
Organic, t/ha	Mineral, kg/ha
IN 1	Spring wheat	2,0		Nitrofos, grade A, 120
Chestnut medium loamy	Alfalfa for hay
Alfalfa for hay			Potassium chloride, 260
Corn for silage		Cattle manure, 100
Soybeans	1,9
Potato
Winter wheat	3,8
Corn for silage			Liquid ammonia, 200
Sorghum silage		Cattle manure, 120
Spring wheat	2,2
AT 2	Spring wheat	2,5
Southern low-humus chernozem	Sugar beet		Cattle slurry, 180
Pea-oat grass mixture			Ammophos, grade A, premium grade, 150
Sunflower	0,7		Double superphosphate, 90
Millet	1,5	Bird droppings, 25
Corn for grain			Ammonium nitrate, 200
Spring barley	1,9
Soybeans	2,1
Pea-oat grass mixture			Karboammofoska, 85
Sudan grass for silage			Potassium chloride, 265
AT 3	Oats	2,2
Southern heavy loamy chernozem	Alfalfa for hay
Alfalfa for hay
Potato		Bird droppings, 45
Corn for silage			Ammonium sulfate, 135
Winter wheat	4,5
Millet	2,0		Urea (urea), 65
Sugar beet		Pork manure, 175
Spring vetch for green fodder			Potassium magnesium sulfate, 275
Sorghum-sudan hybrid			Sulfoammofos, 80

In the soil

After determining the doses of fertilizers, the balance of nutrients and humus in the soil is calculated, which makes it possible to evaluate the developed fertilizer system and, if necessary, make adjustments to it. It is the scientific basis for planning the use of fertilizers and allows for targeted regulation of soil fertility, protection of it and the environment from pollution by agrochemicals. Assessing the state of the balance of nutrients in the soil – plant – fertilizer system is an important characteristic of the effectiveness of the use of fertilizers in agricultural production.

The balance of basic nutrients in the fertilizer-soil-plant system is a mathematical expression of the cycle of nutrients in agriculture and is assessed by the difference between their input and expenditure.

Are used different kinds balance of nutrients in agriculture: biological, economic, differentiated and effective.

Biological balance provides the most complete picture of nutrient cycling. Incoming items of the biological balance include the supply of nutrients with organic and mineral fertilizers, sediments, seeds, symbiotic and non-symbiotic nitrogen fixation, while expenditure items include the content of nutrients in the main and by-products alienated from the field, as well as in root and post-harvest residues.

Economic balance determined by the gross receipt and alienation of batteries. When calculating the economic balance, all income and expense items are taken into account, including unproductive expenses.

The economic balance characterizes not only the share of fertilizers in small biological cycle, the provision of crops with nutrients, but also the nature of their changes in the soil. It allows quantitative prediction of trends in soil fertility. At the same time, the economic balance does not provide a complete picture of the nutritional conditions of individual crops or crop rotation as a whole, since plants use only part of the nutrients from the applied fertilizers.

Differentiated balance. When calculating this type of balance, the amount of mineral fertilizers does not apply to the entire land area, but only to the area of ​​primary use, i.e. on soils insufficiently supplied with nutrients.

Effective balance is determined taking into account the possible coefficients of use of nutrients from fertilizers in the year of their application or during crop rotation. The balance of nutrients is assessed by indicators of deficiency or excess, intensity, structure.

Deficiency or excess of nutrients represents the difference between all sources of their income and consumption and is expressed in absolute (kg, tons) or relative (%) values ​​for the entire area or unit of area.

Balance Intensity– the ratio of the intake of nutrients to their removal by the crop. Expressed as percentages or ratios. A balance intensity value of less than 100% characterizes a deficit balance, and more than 100% characterizes a positive balance.

Balance capacity– the amount of removal from the soil and all items of replacement of nutrients. It characterizes the power of the circulation of substances. The greater the balance capacity, the more intensive the farming in the region, region, or farm under study.

Balance sheet structure – characterizes the share participation of individual items of income and consumption of batteries. Analysis of the balance sheet structure allows you to evaluate the sources of income and the costs of producing a unit of product.

For the developed fertilizer system in crop rotation, an economic and effective balance of nutrients is most often used. Below we present the methodology for their calculation.

The procedure for calculating the economic (general) balance of fixed assets

Nutrient elements in crop rotation

The economic balance of nutrients is defined as the difference between the amounts of income and expenditure items and is expressed in kg/ha.

The methodology for calculating the economic balance of nutrients in agriculture of the Republic of Belarus was developed at the Research Institute of Soil Science and Agrochemistry of the National Academy of Sciences of Belarus (V.V. Lapa, I.M. Bogdevich, N.N. Ivakhnenko and others. Minsk 2001).

Incoming items

Items of supply of nutrients involved in the calculation of the economic balance are represented by the following components:

P N, P 2 O 5, K 2 O, CaO, MgO, S = P mu + P ou + P o + P s + P b + P n,

where P NPK is the supply of nutrients, kg/ha (arable land, agricultural land or hayfields and pastures);

P mu – receipt of mineral fertilizers, kg/ha;

P ou – income with organic fertilizers, kg/ha (P ou = DS), where

D – dose of organic fertilizers, t/ha;

P o – arrival with precipitation, kg/ha;

P s – arrival with seeds, kg/ha;

P b – biological nitrogen, fixed legumes, kg/ha;

P n – non-symbiotically fixed nitrogen, kg/ha;

P b and P n are taken into account only when calculating the nitrogen balance,

The main source of nutrients is organic and mineral fertilizers, data on the use of which is established in accordance with farm reports (form 9bsh of the State Statistics Committee). Nutrient content (N, P, K, CaO, MgO) in different types organic fertilizers are presented in Appendix 45.

Sulfur in organic fertilizers is tightly bound to carbon and nitrogen and its annual mineralization does not exceed 2%, in manure it contains 0.02–0.06% and in peat – 0.1–0.3% (S).

The supply of nitrogen with precipitation (Po), according to long-term data from the Belhydrometcenter of the Republic of Belarus, is 9.4 kg/ha, P 2 O 5 - 0.5, K 2 O - 10.3, CaO - 25.3, MgO - 5 .0, sulfur (SO 4) – 36.0 kg/ha.

Every year, 3 kg of nitrogen, 1.3 kg of phosphorus, 1.5 kg of potassium are supplied to 1 hectare of arable land with seeds (ps); the arrival of calcium, magnesium and sulfur is represented by insignificant values ​​(0.1–0.3 kg/ha), which are not taken into account when calculating the balance.

Providing plants with nitrogen also comes through the introduction of legumes into the crop rotation, which, thanks to symbiotic nitrogen fixation, provide nitrogen to both themselves and subsequent crops.

According to the generalization of field experiments, the indicators of symbiotic nitrogen fixation for calculating the economic balance are:

– per 1 kg of grain kg of nitrogen: lupine in its pure form – 5.0; broad beans in their pure form – 3.0; peas, pelyushka, vetch, soybeans in their pure form – 2.5; lupine mixed with grain crops – 4.5; peas, pelyushka and vetch mixed with grain crops – 2.0;

– per 1 kg of green mass kg of nitrogen: annual legumes – 0.25; annual legume-cereal grass mixtures – 0.20; alfalfa – 0.40; clover and other perennial grasses (except alfalfa) – 0.35; perennial leguminous and cereal grasses – 0.20; meadow lands with legume-cereal grass stand – 0.15.

For soddy-podzolic soils of the republic, characterized by a relatively low humus content, when calculating the nitrogen balance on arable land, it is recommended to take an average standard of non-symbiotic nitrogen fixation of 15 kg/ha per year.

Expense items

The amount of nutrients consumed by plants to create the biological mass of the crop (grain, straw, stubble and root residues, as well as nutrients partially transferred from the roots to the soil) is called the biological removal of nutrients from the crop. It is divided into household take-out and residual. Economic removal is that part of the biological removal of nutrients that is taken away from the field with products (grain and straw, root crops and tops). If straw or tops are left in the field, then the nutritional elements contained in them are not taken into account in the farm takeaway. The residual part of the carryover is the nutrients remaining on the field with stubble and root residues, fallen leaves, spilled grain and chaff, and also transferred from the roots to the soil.

General item of battery consumption (P) in the calculation

The economic balance is determined by the formula:

R = Rvyn. + Rvysch. + Rer. + Rg.,

where is Rvyn? – removal of nutrients by agricultural crops, kg/ha;

Rvysch. – losses from leaching, kg/ha;

Rer. – losses from soil erosion, kg/ha;

Rg. – gaseous nitrogen losses, kg/ha.

The main source of consumption of nutrients is their disposal with the crop harvest (Rvyn). As a result of generalization of data from field experiments with fertilizers (about 1300 experiments) conducted by the Research Institute of Soil Science and Agrochemistry, regional design and survey stations for chemicalization Agriculture, regional agricultural experimental stations and other scientific institutions of the republic have determined the average values ​​of removal of nitrogen, phosphorus, potassium (with 1 ton of main and corresponding amounts of by-products), which are used in calculating the balance for farms or administrative regions (Appendix 6). When calculating the balance of nutrients, the most labor-intensive task is to determine the removal of nutrients from the crop harvest. These calculations are reduced if we use the removal rates per feed unit of crop production.

The average removal of nutrients (N, P 2 O 5 , K 2 O) per 1 c. unit is quite stable over the years and amounts to 2.1 kg of nitrogen, 0.8 kg of phosphorus, 2.2 kg of potassium.

With this method of calculating the balance, the weighted average yield of crop production per 1 ha in feed units is determined, which is multiplied by the average removal of nutrients from 1 quintal unit.

To develop standards for the removal of calcium, magnesium and sulfur, 184 experiments were used, carried out by different institutions of the republic.

When determining the balance of nutrients, losses of nutrients with infiltration water (Rvysh.) are also taken into account, the value of which depends on the doses of mineral fertilizers, the type and granulometric composition of soils, and meteorological conditions (amount of precipitation). The lighter the soil texture and the more abundant the precipitation, the higher the loss of nutrients.

According to lysimetric studies, depending on the granulometric composition of soils, on average, 16–39 kg of nitrogen, 10–33 kg of K2O, 64–122 kg of CaO, 13–25 kg of MgO, 24–37 are lost from 1 hectare of arable soil per year. kg SO 4 (Appendix 46).

According to available scientific data, phosphorus is practically not washed out of the soil and does not pollute groundwater, therefore, in balance calculations, phosphate losses under this item are not taken into account.

It is known that during liming, calcium loss due to leaching increases, especially on soils with light granulometric composition. The results of research by the Institute of Soil Science and Agrochemistry showed that on soils with a pH KCI of more than 6.0, calcium loss increases by an average of 40% compared to the average data of lysimetric experiments on soils without liming.

At the same time, on acidic soils with a pH KCI less than 5.0, calcium leaching is approximately 20% lower. In this regard, to calculate the calcium balance, the average standard loss of this element on soils with a pH KCI greater than 6.0 must be multiplied by 1.4, and on soils with a pH KCI less than 5.0, multiplied by 0.8.

The effect of liming on the leaching of magnesium is ambiguous, since in some cases calcium cations accelerate its leaching from the soil, which is caused by the displacement of magnesium from the absorbing complex, and in others they can reduce its leaching, while neutralizing the acidity of the soil, which usually contributes to the loss of magnesium. In soil and climatic conditions Central Europe losses of magnesium from leaching range from 15 to 50 kg/ha annually (Baiuer, Baiuerova, 1985, Damaska, 1985); magnesium is lost in approximately the same quantities in the soils of Belarus.

According to the second round of soil surveys, the republic has 425 thousand hectares of arable soils subject to water erosion, of which 295.9 thousand hectares are slightly eroded, 107.9 thousand hectares are moderately eroded, and 21.2 thousand hectares are highly eroded.

Losses of nutrients due to erosion (Rer) vary widely and depend on the intensity of erosion processes and the use of slope lands (Appendix 47).

The highest loss of nutrients is observed on highly eroded soils: nitrogen - 20 kg/ha, phosphorus - 10, potassium - 15, CaO - 25, MgO - 12, SO 4 - 0.20 kg/ha per year, as well as on plowed land and under row crops. When cultivating winter grain crops on eroded soils, the loss of nutrients is insignificant, and under perennial grasses it is practically absent.

Appendix 47 provides standards for the loss of macroelements on arable soils depending on the degree of their erosion, which are recommended to be used when calculating the balance of nutrients in individual farms or areas with a high proportion (more than 30%) of eroded soils. When calculating the balance for regions and for the republic as a whole, they can be ignored.

The amount of loss of nutrients due to erosion in hayfields and pastures is very small, so they can be neglected.

One of the items of nutrient consumption in arable and grassland areas is gaseous losses of nitrogen (Ng), which in field conditions can range from 10 to 50% of that applied with fertilizers. These losses are mainly associated with the processes of denitrification, ammonification and nitrification.

Nitrous oxide, oxide, nitrogen dioxide, ammonia and molecular nitrogen can be released from the soil into the atmosphere. The amount of gaseous nitrogen losses on average amounts to 25% of the total amount applied with mineral and organic fertilizers.

The economic balance of nutrients is defined as the difference between the amounts of income and expenditure items and is expressed in kg/ha and calculated by the formula:

B N, P 2 O 5, K 2 O, CaO, MgO, S = (Pmu+Pou+Po+Ps + Pb+Pn) – (Rvyn + Rvyshch + Rer + Rg)

Based on calculations of the balance of nutrients carried out in long-term stationary field experiments under different soil conditions and levels of fertilizer application (N 45–180, P 20–130, K 60–220), the Institute of Soil Science and Agrochemistry proposed optimal parameters for the intensity of the balance of phosphorus and potassium depending on their content in soils (Appendix 48).

The receipt of batteries is determined according to the incoming items of the balance sheet and recorded in the corresponding rows of the workbook table. The amount of nutrients supplied with mineral fertilizers is found in the corresponding table in the course project workbook. Their intake with organic fertilizers is calculated as follows. In the course project workbook, the saturation of organic fertilizers per 1 hectare of crop rotation area of ​​the corresponding crop rotation is found. Taking into account the supply of nitrogen, phosphorus and potassium with organic fertilizers (Appendix 45), their supply per 1 ha is calculated.

Example 1. The saturation of organic fertilizers in crop rotation is 12 t/ha. Determine the supply of nitrogen, phosphorus and potassium with them.

Solution. With a ton of cattle manure on straw bedding, 5.2 kg of nitrogen enters the soil, and with 12 tons - 62.4 kg, phosphorus - 2.6 12 = 31.2, potassium - 6.2 12 = 74.4 kg.

To determine the amount of symbiotic nitrogen, data on the values ​​of symbiotic nitrogen fixed from the atmosphere remaining in the soil after legume plants are used.

Example 2. In a crop rotation on an area of ​​1000 hectares, lupine occupies 100 hectares, clover - 200 hectares. The yield of lupine (green mass) is 200 c/ha, clover (hay) – 250 c/ha. Determine the supply of symbiotic nitrogen.

Solution. As noted above, lupine fixes 50 kg/ha of nitrogen in symbiosis with nodule bacteria, and 5000 kg per 100 ha. Due to nodule bacteria in meadow clover, the average size of nitrogen fixation is 88 kg/ha, and for 200 ha it is 17,600 kg.

The amount of nitrogen that is fixed in symbiosis with nodule bacteria lupine and clover is divided by the area of ​​arable land in crop rotation and the average amount of symbiotic nitrogen per 1 ha is found:

Then the amount of nutrients supplied to 1 hectare of arable land by crop rotation with mineral and organic fertilizers, nitrogen accumulated by legumes, and non-symbiotic nitrogen, with seeds and precipitation, is summed up and a balance sheet income item is obtained.

It not only has a great influence on increasing crop yields, but also helps to increase the potential fertility of the soil. The nature of these changes is closely dependent on the emerging balance of basic nutrients in agriculture: phosphorus, nitrogen and potassium compounds. With a positive balance, i.e. when the supply of nutrients to the soil exceeds their removal with the harvest, there is an increase in soil fertility; when it is negative, there is a decrease.

During the period of intensive agriculture, the balance of nitrogen, phosphorus and potassium in Russia as a whole was positive, and a gradual accumulation of nutrients in arable soils was observed almost everywhere. The rate of this accumulation varied markedly among the zones of the country and was highest in the Non-Chernozem Zone.

In the zone of distribution of soddy-podzolic soils, the replacement of phosphorus removal by crops in the amount of 1971-1990. amounted to 44.2%, or more than 800 kg/ha of P2O5 was added in excess of removal. As a result, the weighted average content of available phosphorus increased from 62 to 137 mg/kg of soil, or more than 2 times. On gray forest soils, the application of phosphorus during the same period exceeded the removal from the harvest by almost 500 kg/ha, which made it possible to increase the weighted average content of P205 from 57 to 112 mg/kg. An increase in the supply of available phosphorus was also noted in chestnut soils, but to a slightly smaller extent.

Currently, when the use of fertilizers in the country has sharply decreased, the preconditions have been created for the reverse process: soil depletion of nutrients.

To estimate size and speed this process Of interest is information about the balance of nutrients in agriculture in various soil-climatic zones and regions of the country. Agrochemical inspection of specific areas is carried out not annually, but periodically - once every 5-10 years. To gain insight into possible changes in soil nutrient content that may occur between survey cycles, annual crop nutrient balance determinations are required. This will make it possible to predict the direction of changes in the agrochemical properties of the soil and give scientifically based recommendations for maintaining or increasing soil fertility, rational use limited fertilizer resources.

The initial information for determining the balance of nitrogen, phosphorus and potassium is statistical data on the application of mineral and organic fertilizers, data on the yield and gross yield of cultivated crops, data on the structure of sown areas.

The expenditure part of the balance took into account the removal of nutrients from the harvest of all agricultural crops cultivated on arable soils, while the input part took into account the intake of nitrogen, phosphorus and potassium with mineral and organic fertilizers.

Due to the wide variety of soil-climatic and organizational-economic conditions in Russia, the situation in each region is different, so the balance was determined in the agriculture of all subjects Russian Federation.

An analysis of the balance of nutrients in Russian agriculture in 2001 shows that its main feature is a pronounced deficiency character. One of the reasons for this is the very low level of use of mineral and organic fertilizers. On average in the country in 2001, 12 kg of mineral fertilizers of nitrogen, phosphorus, potassium were applied per 1 hectare of arable land, and together with organic fertilizers - 21.4 kg.

The smallest amount of fertilizers was used in Siberia: on average 5.1 kg/ha with deviations from 0.1 kg/ha in the Republic of Tyva to 14.3 kg/ha in the Krasnoyarsk Territory.

At the current level of fertilizer use, the deficit of nitrogen in the Russian Federation as a whole in 2001 was 24.6 kg/ha, phosphorus - 6.6 kg/ha and potassium - 33.6 kg/ha, or a total of 64.8 kg /ha. In not a single subject of the Russian Federation was the balance positive for any element.

An assessment of the nutrient balance by its intensity showed that in the Russian Federation as a whole, the replacement of nitrogen removal with the harvest was 32%, phosphorus - 38% and potassium - 15%.
According to the founder of agrochemistry in Russia D.N. Pryanishnikov, in order to maintain soil fertility and increase yields, it is necessary to return to the fields at least 80% of the nitrogen consumed by the crops, 100% of phosphorus and 70-80% of potassium in the form of organic and mineral fertilizers.

According to the State Agrochemical Service of the Russian Federation, as of January 1, 2001, 53 million hectares, or 42.6%, have low humus content; 36.7 million hectares of arable land, or 31.7% - increased acidity; 24.2 million hectares, or 19.5% - low content of available phosphorus and 11.2 million hectares, or 9% - low content of exchangeable potassium. For the period 1992-2001. the sown area in Russia decreased by 29.2 million hectares, or 25.5%, including for grain crops - by 16.3 million hectares, or 26.3%; fiber flax - by 219 thousand hectares, or 2 times; sugar beets - by 633 thousand hectares, or 44%; fodder crops - by 13.4 million hectares, or 31.5%.

The balance of nutrients during crop rotation is important integral part fertilizer systems.

It characterizes the degree of correspondence between incoming and outgoing items of batteries over a certain time. The balance can be planned (proposed in the fertilizer system design) and real, developed during crop rotation.

In agricultural practice, there are three types (levels) of balance: in crop rotation, on-farm and external (for the region, country).

Analysis of the fertilizer system on the farm is carried out by drawing up a complete or simplified balance of nutrients. In a simplified balance, a comparison is made of the amount of nutrients applied with organic and mineral fertilizers with the economic removal of nutrients (removal of main and by-products). The full balance is based on more detailed accounting of income and expense items. The incoming part includes the supply of nutrients with fertilizers, seeds, sediments, and the supply of nitrogen due to symbiotic and non-symbiotic fixation. Expenditure items include the alienation of nutrients with the crop, losses due to leaching, denitrification and erosion. The balance is expressed in kg/ha or in % (balance intensity).

The balance of nutrients allows you to control income and expenditure items, predict and plan changes in agrochemical indicators of soil fertility.

Balance of nitrogen, phosphorus and potassium. A reliable balance of nutrients in a farm or crop rotation can be compiled only with strict quantitative accounting of its income and expenditure items. Most farms mainly control the application of mineral and organic fertilizers to the soil. The remaining balance sheet items are determined by weighted average indicators, which may differ significantly from the actual ones.

Thus, due to significant fluctuations in the indicators of income and expense items of the complete economic balance sheet, when compiling it, it is necessary to use averaged standard indicators. For example, the supply of nitrogen due to nitrogen fixation by free-living microorganisms ranges from 4-9 kg/ha, symbiotic nitrogen fixation by leguminous crops - 4090 kg/ha, with precipitation 3-12 kg/ha. Wide fluctuations are also typical for nitrogen losses as a result of denitrification (about 15-30% of that added with fertilizers), nitrate leaching (5-15 kg/ha), soil erosion (5-25 kg/ha), etc.

Losses of potassium and phosphorus occur only on light sandy soils in areas of sufficient moisture and on soils subject to erosion.

It should be noted that when compiling a complete balance of nutrients in crop rotation and farming, expenditure items (denitrification, leaching) are largely compensated by income items (arrival with precipitation, due to nitrogen fixation), therefore, to assess the direction of changes in fertility, it is quite enough to use a simplified balance of nutrients.

To assess the state of the balance, the following indicators are used:

1. Balance sheet structure - characterizes the share (%) of individual incoming and outgoing items of batteries in the balance sheet;
2. The capacity of the balance is determined by the total number of batteries in the input and output parts of the balance.
3. The take-out return (reimbursement) coefficient (RRR) is the ratio of the arrival of batteries to their consumption. If it is greater than 1, then the balance is quantitatively positive to the extent that the ECV is greater than 1.0; when KVV = 1.0, the balance is zero, and when KVV is less than 1.0, the balance is correspondingly negative.
4. Balance intensity is the ratio of the supply of batteries to their consumption, expressed in %, as a percentage. For example, if the income of phosphorus (P 2 O 5) is 60 kg/ha, and the consumption (removal by crops and other expenditure items) is 50 kg/ha, then the intensity of the balance is (60:50·100) = 120%.
5. Balance coefficient (removal coefficient) is the ratio of the removal (kg/ha) of nutrients by plants to their application (kg/ha) with fertilizers, expressed in %. So, if the removal of nitrogen by the crop is 90 kg/ha, and 60 kg/ha is applied, then the removal coefficient is 150.

The balance of nutrients is the difference (kg/ha, g/m2) or ratio, expressed as a fraction of a unit or as a percentage, of all input and expenditure items of elements in the agrocenosis for a certain period of time.

The balance can be positive (indicated by the “+” sign) if the supply of batteries is greater than the consumption by a certain amount (kg/ha, g/m2); negative or deficit (indicated by the sign “-”), if the receipt of elements is less than their consumption; zero (deficit-free, balanced, with the sign “0”) if the supply of nutrients is equal to the consumption.

The balance coefficient (Bk) of the use of nutrients from fertilizers is the ratio of the consumption of elements to their income, expressed in shares or percentages. If the balance coefficient is less than 1.0 (100), then the balance of nutrients in the agrocenosis will be positive; if Bq values ​​are more than 1.0 (100%), the balance will be negative.

The humus content in the soil is in constant dynamic equilibrium. Despite the relatively high resistance of humus to microbiological decomposition (its age is 500 - 5000 years), processes of its mineralization and new formation constantly occur in the soil. Therefore, the humus status of soils depends on which of these processes predominates—mineralization or humification.

The amount of humus is one of the most important indicators of soil fertility. Its reserves largely determine the agrochemical, agrophysical and biological properties of the soil. Soils rich in humus are highly buffered in relation to many factors - food, water, temperature and air conditions. In such soils, the loss of nutrients from leaching is reduced, the rate of decomposition of pesticides increases, and the costs of plants, especially roots and tubers, are reduced. mechanical work their root system to deformation and displacement of soil aggregates during growth, the energy costs for tillage are significantly reduced. The humus content depends on soil and climatic conditions, the structure of crop areas, the intensity of soil cultivation, the amount of fertilizers and ameliorants used. With long-term use of soils as arable land, humus is continuously mineralized, and nutrients are alienated with the harvest or as a result of unproductive losses. The greatest losses of humus due to its mineralization and erosion processes occur in fallow soil and under row crops compared to perennial grasses and grain crops.

The law of the return of substances to the soil, which was first formulated in 1840 by the author of the theory of mineral nutrition of plants, J. Liebig, is one of the key, fundamental laws in agriculture. The essence of the law is as follows: to preserve soil fertility, all nutrients that are removed from the soil by plants or during any other processes must be returned.

The law of equivalence and irreplaceability of plant growth and development factors. Determining the state of the balance of nutrients in crop rotation allows you to control the direction and intensity of changes in the content of nutrients in the soil of individual fields and crop rotation as a whole, and to predict ecological state agricultural landscapes and surrounding areas, regulate the amount and composition of fertilizers used;

Balance calculations for specific fields are carried out based on real data on the receipt and consumption of batteries. In the absence of results for individual balance sheet items, averaged reference data or recommendations developed by regional scientific institutions are used. Therefore, the battery balance when used to calculate averaged data is approximate.

The soil-plant-fertilizer system is highly dynamic, so predicting the nature of the interaction of these three main components of the system, presented by D.N. Pryanishnikov in the form of a triangle, is quite difficult due to the unpredictability of weather conditions, the spread of diseases and pests.