1

Stolbovoy Vladimir, Nicola Filippi and Luca Montanarella Land Management and Natural Hazards Unit, Joint Research Center EC, Ispra,

Italy

Verification of the changes of carbon stock in mineral soils of the European

Union

Ispra, November, 2006

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• European policies urgently request to monitor the content of organic carbon in soil;

• To support this policy the soil survey needs to provide transparent, measurable, verifiable and economically sound information;

• This information is based:– method to detect the changes of organic carbon in

soil;– System of parameters describing current status of

organic carbon content and indicating potential for carbon management.

Introduction

November 2006

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• Introduce new Area-Frame Randomized Soil Sampling;

• Demonstrate results of the method testing.

Objectives

November 2006

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B. Composite sampling

(A) Advantage - statistically sound; Disadvantage – resources demanding, high cost, impractical.

1

10

100

1000

10000

0 10 20 30 40 50 60

Variability (CV), %

Num

ber

of s

ampl

es

50 tC/ha

75 tC/ha

100 tC/ha

SOC content (0-30 cm)

Number of samples (P0.05)

Why do we need a method for soil sampling?

(B) Advantage – simple, low cost, practical; Disadvantage – unknown accuracy.

A. Simple point sampling

Random layout

Systematic layout

November 2006

5

(The average C sequestration is 6tC for the control (4ha) plot; the laboratory cost of the C detection 6-16 EURO for sample)

  

Land cover

Conventional (IPCC, 2003)

Variability, %

Number of samples

Cost per tC

Cropland9 243 243-

643

Pasture15 675 675-

1800

Cost of carbon detection in soil by point sampling

November 2006

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669.0

326.0

5917 62605951.3

5985.6

6019.09

6054.26088.5

6122.86157.1

6191.46225.7

634.7

600.4

566.1

531.8

497.5

463.2

428.9

394.6

360.3

79 40

100

44 93 16 67 54

64 32 47 95 24 58

51

53

56 1 72 43 97

8

91 1825

68 94 22 85 17

70

34

31 73

42

84 50

61

33

87

27

48

10

28

66

88

Sampling site (m)

4 69 75 12 90 76 23 41 99 2

60 29 7 92 19 45 57

20 80 78 21 83

98

719

38

7459 14

30 39 35 49 82 3

9646

89 6 66 77 13 81

65

1537

11

3626

63

52

55

5

62

Max

Axi

s

5.6

17.1

5

34.3

5.6

17.15

34.3

Selected sampling site (first

sampling)

Selected sampling site (second sampling)

Area-Frame Randomized Soil Sampling (AFRSS) takes advantages

November 2006

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Sam

plin

g de

pths

Sub

soil

hor

izon

Pasture

Plo

ugh

hori

zon

Sub

soil

hor

izon

cm010

20

30

40

506070

80S

ubso

il h

oriz

on

Cropland Forest

Min

eral

ho

rizo

nO

rgan

ic

laye

r

Source: Stolbovoy et al., 2005

Minimization of sampling depths

November 2006

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Programming of sampling strategy

November 2006

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(The average C sequestration is 6tC for the control (4ha) plot; the laboratory cost of the C detection 6-16 EURO for sample)

  

Land cover

Conventional (IPCC, 2003) Area-Frame Randomized Soil Sampling

Variability, %

Number of samples

Cost per tC

Variability, %

Number of samples

Cost per tC

Cropland9 243 243-

643 n.a. 3 3-8

Pasture15 675 675-

1800n.a 9 3-8

n.a. = not applicable Source: Stolbovoy et al., 2006

Economic effectiveness of AFRSSg

November 2006

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0

10

20

30

40

50

60

1 2 3 4 5

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

Plot area, ha Euro/tC

Eu

ro

0

10

20

30

40

50

60

1 2 3 4 5

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

Plot area, ha Euro/tC

0

10

20

30

40

50

60

1 2 3 4 5

0

5

10

15

20

25

30

35

Plot area, ha Euro/tC

Eu

ro

( average carbon sink is 1.5 tC/ha; the cost of lab determination is 16 EURO per sample)

Source: Stolbovoy et al., 2006

Lower cost for larger fields

ha

November 2006

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(cropland (Piemonte), first and second samplings)

Profile, N

Depth,cm

C, % Bulk density,g/cm3

Soil carbon density, kgC/m3

Carbon content for profile, tC/ha

Soil carbon stock,tC (area 4 ha)

Average soil carbon stock, tC(area 4 ha)

Reproducibility, %

Cropland Skeletic Cambisol, first sampling

C1S 0-25 2.43 1.29 7.86 n.a.*314.4

   

C22S   2.16 1.43 7.72 n.a.308.8

301.1  

C8S   2.04 1.37 7.00 n.a280.0

  

    Cropland Skeletic Cambisol, second sampling 3

C1Ss 0-25 1.99 1.52 7.60 n.a.304.0

   

C22Ss   2.00 1.40 7.00 n.a.280.0

292.0  

C8Ss   1.55 1.25 4.85 n.an.a.

   

Source: Stolbovoy et al., 2006

Practical precision/reproducibility

November 2006

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• The suggested Area-Frame Randomized Soil Sampling (AFRSS) combines advantages of composite sampling with randomized positioning of the sampling sites.

• The field test shows that the AFRSS assures practical precision/reproducibility within 3% of initial carbon stock, simplicity, transparency and low cost.

• The AFRSS allows easy programming/computation of the sampling strategy.

Conclusions

November 2006