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

2 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

3 Introduce new Area- Frame Randomized Soil Sampling; Demonstrate results of the method testing. Objectives November 2006

4 B. Composite sampling (A)Advantage - statistically sound; Disadvantage – resources demanding, high cost, impractical. 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 Cropland Pasture Cost of carbon detection in soil by point sampling November 2006

Sampling site (m) MaxAxis Selected sampling site (first sampling) Selected sampling site (second sampling) Area-Frame Randomized Soil Sampling (AFRSS) takes advantages November 2006

7 Sampling depths Subsoil horizon Pasture Plough horizon Subsoil horizon cm Subsoil horizon CroplandForest Mineral horizon Organi c layer Source: Stolbovoy et al., 2005 Minimization of sampling depths November 2006

8 Programming of sampling strategy November 2006

9 (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 Cropland n.a.33-8 Pasture n.a93-8 n.a. = not applicable Source: Stolbovoy et al., 2006 Economic effectiveness of AFRSSg November 2006

Plot area, haEuro/tC Euro Plot area, haEuro/tC Plot area, haEuro/tC Euro ( 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

11 (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) Reproducibili ty, % Cropland Skeletic Cambisol, first sampling C1S n.a.* C22S n.a C8S n.a Cropland Skeletic Cambisol, second sampling 3 C1Ss n.a C22Ss n.a C8Ss n.a n.a. Source: Stolbovoy et al., 2006 Practical precision/reproducibility November 2006

12 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