Information for farmers

Planned crop yield volume, removal of nutrients by plants, content of available nutrients in soil, type and texture of soil have to be considered in order to estimate the amount of fertilizer that has to be applied.

Regional fertility rate achieved, climate conditions and natural soil fertility should not to be neglected as well.

In practice, the demand for nutrients is characterized by their removal by plants considering the by-products as well. 

In practice, the demand of plants for nutrition elements is characterized by the nutrients’ removal. Removal is the amount of nutrients taken away from soil with the yield practically harvested ( for instance with the grain) including the by-products (for instance, chaff) and excluding the plant residues left on the field (for instance, roots and stubble) (see Removal).

Removal of major nutrients with the crop yield

Crop

Major production

Removal with 1 t of yield and the corresponding amount of by-products, kg

N

P2O5

K2O

CaO

MgO

Ensilage corn

Green material

3,3

1,2

4,2

1,3

1,0

Below are approximate indexes of the consumption of nutrients from soil and from fertilizers by corn plants that can be used to estimate the amount of mineral fertilizers for sod-podzol and gray wood soils.

Indexes of the consumption of nutrients from soil and fertilizers by plants (for sod-podzol and gray wood soils), %

Crop

From soil (with medium and higher nutrients content)*

From mineral fertilizers during the first year

From organic fertilizers during the first year

P2O5

K2O

N

P2O5

K2O

N

P2O5

K2O

Grain crops, annual and permanent grasses

5

10

50-60

15-25

40-50

20

30

40-50

*The indexes can be one and a half or two times as much by low nutrients content in soil.

Example of estimation of amount of mineral fertilizers required in order to achieve the planned crop yield of winter wheat, ensilage corn and sugar beets.

Index

Winter wheat

Ensilage corn

Sugar beet 

N

P2O5

K2O

N

P2O5

K2O

N

P2O5

K2O

Planned crop yield, c/ha

40c/ha

400 c/ha

400 c/ha

Removal of nutrients with the planned yield, kg

115

45

80

132

50

168

160

65

260

Nutrients taken up from soil

30

15

30

30

15

30

30

15

60

Taken up from 60 t/ha of organic fertilizers, kg

-

-

-

50

25

80

60

30

120

Mineral fertilizers required, kg/ha

85

30

50

55

10

60

100

20

80

Consumption of nutrients from mineral fertilizers, %

65

20

50

65

20

50

65

20

70

Amount of the major nutrient that should be applied with mineral fertilizers considering the consumption indexes, kg/ha

130

50

100

85

50

120

107

100

115

Amount to apply for ammonium nitrate, kg/ha

370

*

*

245

*

*

305

*

*

* Application dose (Dappl.) for various types of phosphorus and potassium fertilizers is estimated in accordance with the content of nutrition elements (e) in them using the following formula: Dappl. = (х*100)/e. Where х – dose on primary nutrient basis.

High yield grain crops with good quality characteristics are mostly influenced by the system of nitrogen fertilizers application.