SOIL ORGA IC MATTERMO ITORI G A D MA AGEME T
I BELARUS

Prof. Dr. Iossif BOGDEVITCH,
Dr. Natallia MIKHAILOUSKAYA
and Nadezda TERESHCHENKO
Research Institute for Soil Science and Agrochemistry,Minsk, Belarus.
Humic Substances in Ecosystems 8, Šoporňa 13.-17.9.2009 Slovakia

1Goal and tasks of research• Soil fertility status is commonly evaluated every 4 years inBelarus – SOM, pH value, P2O5, K2O and micronutrients.
Sustainable optimum SOM (humus) management has priority
importance to prevent soil fertility degradation or pollution.

• The research aims to quantify the dynamics of SOM
content and humus balance in arable land in relation
to soil properties and to the main management
factors at farm and district level .
Research tasks:• Dynamics of SOM content in arable land for period 1996-2008.
• Ecological SOM function on contaminated land after Chernobyl
accident• To quantify the relation of management factors to humus
reproduction.
• To develop multiple regression model for prognosis of SOM
balance at farm and district level.

2Humic Substances in Ecosystems 8, Šoporňa 13.-17.9.2009 Slovakia

Materials and methods• The dynamics of mean Soil organic matter (SOM) content
and balance in arable soils of Belarus, Soil texture, Share ofdrained soils (%) according to data of State Agrochemical
Soil Survey dad been studied:- on country (National) level over the period 1965 - 2008;- for 118 districts of Belarus over the period 1996 - 2008;- for 160 farms of Gomel region over the period 1996 - 2008;• The data for factors related to dynamics of SOM content
and balance in arable land for studied periods had beencollected from the State Statistics Committee and fromAnnual Farm Reports:- annual farmyard manure (FYM) and fertilizer application
rates, t ha-1, kg ha-1;- cropping pattern (share of Perennial grass and ratio
Perennial grasses; Row crops) on arable land;- productivity of arable land (cereal units t ha-1);• Long-term field experiment with FYM and fertilizer rates on
Luvisol loamy sand soil contaminated with 137Cs and 90Sr.
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Humic Substances in Ecosystems 8, Šoporňa 13.-17.9.2009 Slovakia

Land of Belarus
Area
103 haDrained103 ha%

Total

20.7

100.0

3.4

Agriculture

8.9

43.0

2.9

Arable5.526.6

1.3

Orchards

0.12

0.60

Grassland

3.3

15.9

1.6

Forest

8. 5

40.2

0.3

Owners:%State & cooperative farms

81.2

Personal plots

15.3

Private farmers

0.6

Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

4

Dynamics of mean SOM content inarable land of Belarus (1965-2008)30

2,52,25

2,27

2,26

2,25

2,04

2
1,77

SOM content, %

25

1,93
1,77

1,78

20
1,5151100,5

SOM content,%5

Share of land with SOM content <1.5%

2,182,28

Share of land with SOM content <1,5%001965197019751980

1984

1988

1992

1996

Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

2000

2004

2008

5

Dynamics of cattle numbers and annual
rates of manure application on arable landof Belarus
8000
14,4Manure, t ha-1

6000
Cattle. 1000 heads

14

Cattle numbers

13,3

12

5000

108,9
8,1

4000

8

7
6,2

3000

6

2000

4

1000

200
1985

1990

1996

2000

2004

Cattle stockhead/ 100 ha
1985 - 81,
Humic
Substancesin :Ecosystems
8, 2008 – 46.
Šoporňa 13.-17.9.2009 Slovakia

Manure. t ha-1

7000

16

2008

6

Dynamics of cropping pattern on arable land
in Belarus for period of 1996-2008
40

Perennial grasses

335

Row crops
Ratio Perennial grasses:Row crops

30
Share of crops, %

2,52

1,925
20

1,51,4

15
10,8

100,5

Ratio Perennial grasses : Row crops

2,8

500
1996

2000

2004

Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

2008

7

Dynamics of SOM content in arable landof Belarus (1996-2008)
increase- 0.0-0.10 %- 0.11 and > %2008 SOM, %-<< 2,00-2,01
2,01 – 2,30
-2,31
2,31 – 2,60
- <2,60

The soil tests indicated a fall in SOM content on 60 % of arable land.
Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

8Tag of 90Sr transfer from soil to spring wheat grain
in relation to manure and K-fertilizer rates
RF due to manure rates 2.0-2.4
RF due to fertilizers 1.3-1.6

90Sr, S. wheatControl

1,2

N90 P60
NP K601Tag 10 -3 m 2 kg -1

NP K120
0,8

NP K180

0,60,40,200

816Manure, t ha-1
Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

9Radiological efficiency of FYM application inlong-term experiment on Luvisol loamy sand soil
Crop Yield,cereal units t ha-1
Fertilization

Tag of 137Сs transferfrom soil tocrops, %Tag of 90Sr transferfrom soil tocrops, %19992003

20042007

19992003

20042007

19992003

20042007

Control

2.1

2.5

100

100

100

100

FYM 8 t ha-1

3.0

3.1

69828574

FYM 16 t ha-1

4.0

4.0

6171

67

67

N60Р90К90

3.7

4.3

60

70

85

78

NPK +FYM 8 t ha-1

4.9

5.0

50

5867

65

5.86

5.90

43474752

NPK +FYM 16 t ha-1

Total RF due to FYM and fertilizers is 2.1-2.2 for 137Сs (decreasing with time) and1.9-2.1 for 90Sr (increasing with time).
Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

10Accumulation of radionuclides in hay of
perennial grass versus the SOM content inLuvisol loamy sand soil
(deposition of 137 Cs 370 kBq m-2 and 90Sr – 37 kBq m-2)
Radionuclide
activity, Bg kg-1

2500

137Cs
90Sr

2000

1500

1000

500

01,1

2,2

3,0

3,5

SOM content,%

RF for 137 Cs -1.7; for Sr – 1.9.
Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

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Mean soil organic matter content (%) inarable land related to share of drained soils(%) at 118 districts of Belarus (2005-2008)
3,50
y = 0,0126x + 1,99
R2 = 0,50

3,00

SOM content, %

2,50
2,00
1,50
1,00
0,50
0,00
0,0

10,020,030,040,050,060,070,0

Share of drained soils,%

Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

12Balance of SOM content for period 19962008 related to share of fine textured soils
in arable land of 118 districts of Belarus0,4y = -3E-05x 2 + 0,0049x - 0,1251
R2 = 0,22

Balance of SOM content, %0,30,20,100102030405060

7080

90

100-0,1-0,2-0,3-0,4
Share of fine textured soils, %Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

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Dynamics of SOM content at groups offarms related to annual manure rates(1996-2008)
12

3,5
10,8

10

2,58
7

2

6,5

6
1,54,8Manure, t ha -1

Soil organic matter, %341

SOM 1996
SOM 2008

0,52Manure t ha-1

0032511715

Number of farms

Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

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Difference of SOM content
for period 1996-2008 related to ratio
Perennial grass: row crops at districts of Belarus
0,4
y = -0,0055x 2 + 0,0733x - 0,13
R2 = 0,21

Difference of SOM content,%

0,30,20,1
00,0

1,0

2,0

3,0

4,0

5,0

6,0

7,0

8,0-0,1-0,2-0,3-0,4Ratio Perennial grasses : row crops

Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

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Factors related to SOM content balance
for period 1996-2008
160 farms of Gomel region
Y - SOM balance differed from 8.2
to -11.5 g kg-1 of soil
in dependence from variables:• Х1 – initial SOM content, g kg-1
• Х2 – share of Perennial grasson arable land, %• Х3 – annual rate of manure
application, t ha-1
• Х4 – annual rate of fertilizer
application, NPK kgha-1
Y = 4.21 - 0.3049Х1 + 0.0979Х2 +0.3633Х3 – 0.0145Х4R2 = 0.38 (р <0.001)

118 districts of Belarus
Y - SOM balance differed from 3.3
to -3.5 g kg-1 of soil
in dependence from variables:• Х1 – initial SOM content, g kg-1
• Х2 – share of fine textured soil
in arable land, %• X3 – ratio Perennial grasses:
Row crops• Х4 – annual rate of manure
application, t ha-1
• Х5 – annual rate of fertilizer
application, NPK kgha-1
Y = 23.94 -1.1856Х1 + 0.1199Х2 +2.3160Х3 +1.5025Х4 – 0.1013X5
R2 = 0.38 (р <0.001)

Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

16Balance of SOM content related to annualFYM rates in long-term experiment on Luvisol
loamy sand soil3019982008
2010 Predicted

SOM content, g kg -1

25201510500816

Annual FYM rate, t ha -1

Experimental data 1998-2008, predicted – 2010. Deviations of predicted fromexperimental (6-11-1%). Deviation on Luvisol clay loam soil-15%. Deviations onsandy soil (at FYM 7t ha-1 2-3%, at 14 t ha-1 – 11-16%).
Humic Substances in Ecosystems 8,Šoporňa 13.-17.9.2009 Slovakia

17Conclusions•••••

The soil tests (1996-2008) indicated a fall in SOM content on 60 % of arable
land of Belarus. The most significant lost of humus stock in arable layer(in average 5.8 t ha-1 or 6.8% of initial value) was admitted on land of 20
districts contaminated after Chernobyl accident. Ecological function of
SOM is related to the reduction of radionuclides 137Cs and 90Sraccumulation in crop production up to factor 2.
The long-term prognosis of humus balance on district and farm level isrequired. However process-based humus balance methods from long-term
field experiments are complicate and time consuming. The acceptability ofthese methods by extension experts and farm managers are rather low.
To develop simply prognosis tool the analysis of soil monitoring data
combined with agricultural statistics on farm and district level had been
done. It was found that SOM balance in arable land is closely related toinitial level of SOM content, annual rate of FYM application and cropping
pattern (share of perennial grass or ratio Perennial grasses: row crops).
Two multiple linear regression models had been developed which explain
up to 38% of SOM balance variations related to mentioned factors at highconfidence level (p <0.01). The models were validated against data oflong-term experiments making its more applicable for different regions ofcountry.
The found relationships may be used as a tool to predict and evaluate
SOM changes. It may be useful for the selection of reliable management
practices to achieve satisfactory and sustainable levels of SOM content.
Sustainability in humus reproduction implies the prevention of intolerable
decrease as well as excessive increase of the humus content.
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Humic Substances in Ecosystems 8, Šoporňa 13.-17.9.2009 Slovakia