SOIL ORGANIC MATTER in the

BIOBASED ECONOMY HANS VAN VEEN Netherlands Institute of Ecology www.nioo.knaw.nl

what is soil organic matter?

Soil Organic Matter, SOM, is the collective term representing all organic constituents in the soil, including undecayed plant and animal tissues, their partial decomposition products, and the soil biomass (http://karnet.up.wroc.pl)

what is SOM doing? • • • • • • •

Bind soil particles together in stable aggregates Influence water holding and aeration Major source of cation exchange capacity Source of pH buffering Binding site for heavy metals and pesticides Food source for microbes and small animals Major reservoir of plant nutrients

(http://www.dpiw.tas.gov.au/inter.nsf)

Why care about SOM?

It largely determines soil quality! soil’s ability to provide ecosystem and social services through its capacities to perform its functions under changing conditions EU definition

main soil functions • Biomass production • Storing, filtering and transforming nutrients, substances and water • Biodiversity pool such as habitats, species and genes • Source of valuable materials • Acting as carbon pool

composition of SOM T < 2 years

T > 500 years

T < 20 years

SOM = 2-10 % of Total Soil Matter

humus formation

SOM Models

cultivation leads to SOM reduction

Van Veen & Paul, Can J Soil Sci, 61, 185-201,1981

Losses of soil organic matter due to cultivation Country

Years Loss Reference of cultivation ( % C or N) ____________ ____________ ____________ __________ Australia

?

50

Greenland, 1982

Canada

60-80

40-60

Campbell et al, 1976

Canada

70

57

Voroney et al, 1982

Canada

22

20

Newton et al, 1945

USA

60

40

Stevenson, 1965

reality of soil arrangement

soil degradation

resources of soil organic matter

Above ground residues

Root turnover products

biobased economy

biofuel demand Zwart & Kuikman ASA, CSSA, ASSA meeting 2012, Cincinnati

biomass types for biobased energy

Zwart & Kuikman ASA, CSSA, ASSA meeting 2012, Cincinnati

why care about SOM in the

bio-based economy? Changes in quantity (< !) and quality of plant residue inputs

Impact on soil quality

SOM balance at various biomass production systems Bodemorganischestofbalans SRC hout voor boiler SRC hout voor CV

SRC hout voor CFBC Snijmaïs WKK (+mest)

Maize

Snijmaïs WKK Snijmais groen gas (+mest) Snijmais groen gas

Resthout voor CFBC Resthout voor boiler Resthout voor CV

Rape seed

Koolzaad FAME Palmolie FAME

Suikerbiet ethanol (zand) Suikerbiet ethanol (klei)

Straw residue removed residue left

Stro ethanol (lignine verbrand) Stro ethanol (lignine retour) Tarwe ethanol (stro op veld)

Soja FAME

Sugar cane, residue left residue burnt

Maïs ethanol Suikerriet ethanol (top+blad op veld) Suikerriet ethanol (top+blad verbrand) -25 -20 -15 -10 -05

00 05 kg/GJ

10

15

20

Croezen, Odegard, Bergsma & Langeveld, Soil in the Bio-economy ( in Dutch), publ nr 13.2813.19, 2013, CE-Delft

25

CO2 emission-reduction

at various biomass production systems Netto CO2-eq emissie Bodemorganischestofbalans SRC hout voor boiler

SRC boiler SRChout hout voor voor CV SRC hout voor CV

SRC hout voor CFBC

SRC hout voor CFBC

Snijmaïs WKK (+mest)

Maize

Snijmaïs WKK (+mest) Snijmaïs WKK

Snijmaïs WKK

Snijmais groen gas (+mest)

Snijmais groen gas (+mest) Snijmais groen gas

Snijmais groen gas

Resthout voor CFBC

Resthout voor CFBC

Resthout voor boiler

Resthout voor boiler Resthout voor CV

Resthout voor CV

Rape seed

Koolzaad FAME Koolzaad FAME Palmolie FAME Palmolie FAME Suikerbiet ethanol (zand) Suikerbiet ethanol (zand) Suikerbiet ethanol (klei) Suikerbiet ethanol (klei)

Straw, residue removed residue left

Stroethanol ethanol(lignine (lignine verbrand) Stro verbrand) Stroethanol ethanol (lignine retour) Stro (lignine retour) Tarweethanol ethanol (stro op veld) Tarwe (stro op veld)

Soja FAME Soja FAME

Sugar cane, residue left residue burnt

Maïs ethanol Maïs ethanol Suikerriet ethanol (top+blad op veld) Suikerriet ethanol (top+blad op veld)

Suikerriet ethanol (top+blad verbrand) Suikerriet ethanol (top+blad verbrand)

-120

-25 -100 -20 -15 -10 -60 -05 -80

00-40 05 -20 10 kg/GJ kg CO 2-eq per GJ

Croezen, Odegard, Bergsma & Langeveld, Soil in the Bioeconomy ( in Dutch), publ nr 13.2813.19, 2013, CE-Delft

150 20 20 25

reduction of SOM per ton saved CO2 emission per sector

Afnam e organische stof per ton vermeden CO2-eq

afname BOS (kg)/ ton vermeden CO2

350,0 300,0 250,0 200,0 150,0 100,0 50,0 0,0 E+W

Transport

Chemie

-50,0 -100,0

Croezen, Odegard, Bergsma & Langeveld, Soil in the Bio-economy ( in Dutch), publ nr 13.2813.19, 2013, CE-Delft

Concluding remarks  Healthy soil requires sufficient SOM  Maintenance of SOM requires sufficient plant residue input  Sustainable bio-based economy requires sufficient care about SOM

Acknowledgement Advisors: Geert Bergsma, CE Delft, NL Kor Zwart, Alterra, Wageningen, NL Peter Kuikman, Alterra, Wageningen, NL

Sponsors: BE-Basic, Delft, NL NIOO-KNAW, Wageningen, NL

soil erosion

http://soils.usda.gov/sqi/concepts/soil_organic_matter/som_manage.html

Effects of a BIOBASED Economy • More biomass needed for: – Food – Fuel – Fossil fuel based products

Zwart & Kuikman ASA, CSSA, ASSA meeting 2012, Cincinnati

Biobased Energy

Zwart & Kuikman ASA, CSSA, ASSA meeting 2012, Cincinnati

Biobased Energy

Source: EEA, (2006) Zwart & Kuikman ASA, CSSA, ASSA meeting 2012, Cincinnati

Effects BBE on soil • Less crop residues return directly to the soil • Less biomass available for composting • Further processing of animal manure to extract more energy: less organic matter return to the soils

Zwart & Kuikman ASA, CSSA, ASSA meeting 2012, Cincinnati

Functions SOM

http://grdc.com.au/uploads/documents/cso000291.pdf Zwart & Kuikman ASA, CSSA, ASSA meeting 2012, Cincinnati