Unlocking biochar technologies for African farming systems

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Unlocking biochar technologies for African farming systems Dries Roobroeck, Kristina Röing de Nowina, Geoffrey Kimutai, Erik Karltun, Gert Nyberg, Mary Njenga, James Kinyua,

1 Unlocking biochar technologies for African farming systems Dries Roobroeck, Kristina Röing de Nowina, Geoffrey Kimutai, Erik Karltun, Gert Nyberg, Mary Njenga, James Kinyua, Sara Gottenhuber, Olof Andrén, John-Baptist Tumuhairwe, Janice Thies, Bernard Vanlauwe, Thomas Kätterer, Rebecca Hood-Nowotny, Yahia Mahmoud, Cecilia Sundberg Partners: Funding:

2 Total productivity index ( 6-65= 00) Challenges in smallholder farms Stagnation of crop productivity < > Degradation of organic carbon stocks and fertility functions of soils Only 0 to 50% of biomass residues in smallholder farming systems are being returned to soils because of competition for fodder, building material, fuel, etc. All developing countries Sub-Saharan Africa Source: USDA, Economic Research Service Year

3 Soil C stock (ton ha - ) Challenges in smallholder farms Stagnation of crop productivity < > Degradation of organic carbon stocks and fertility functions of soils Only 0 to 50% of biomass residues in smallholder farming systems is being returned to soils because of competition for fodder, building material, fuel, etc. High fertilizer, with residue Low fertilizer, without residue Source: Zingore et al., 006 Time (years)

4 Challenges in smallholder farms Stagnation of crop productivity < > Degradation of organic carbon stocks and fertility functions of soils Only 0 to 50% of biomass residues in smallholder farming systems is being returned to soils because of competition for fodder, building material, fuel, etc.!!!! Labour intensity, residue quality and indirect valuation curtail organic resource management

Window for biochar technologies Economies in sub-saharan Africa are largely biomass centered < > 600 million people and many industrial processes depend on wood, charcoal and crop residues as

5 Window for biochar technologies Economies in sub-saharan Africa are largely biomass centered < > 600 million people and many industrial processes depend on wood, charcoal and crop residues as fuel for energy generation After: Johannes Lehmann (07) Conceptual diagram of organic resource fluxes in smallholder landscapes at current (left) and relative benefits of biochar technologies (right)

Window for biochar technologies Biochar inputs to soils are able to boost productivity of

07) Up to 97% of C from biochar inputs can be retained in soils for decades (Wang et al.

Gasifier cook stove Research focus Charred maize cobs (right) ) Do biochar inputs sustainably

6 Window for biochar technologies Biochar inputs to soils are able to boost productivity of staple crops in the Tropics (Jeffrey et al. 07) Up to 97% of C from biochar inputs can be retained in soils for decades (Wang et al. 06) Gasification of biomass allows generating power with waste biomass and abate GHG emissions Gasifier cook stove Research focus Charred maize cobs (right) ) Do biochar inputs sustainably increase crop production and resilience, as well as sequester C in soil? ) How much do gasifier systems reduce fire wood consumption and harmful emissions?

Crop x Soil x Biochar studies Long-term trials - Rotations

years (= 0 seasons) - NPK fertilizer applied to maize -

) Dosage x feedstock trials - Continuous maize without and

over years - One time biochar (BC) application with

NPK + Biochar Location Climate Soil Biochar Siaya Embu Kwale

Nitisol ferric Acrisol Maize cobs Coffee husks Coconut

of mineral and/or organic inputs (inoculation, vermicompost,

7 Crop x Soil x Biochar studies Long-term trials - Rotations of maize and soybean on farms with block replicates over 0 years (= 0 seasons) - NPK fertilizer applied to maize - One-time biochar input of 00 ton ha - (Acacia sp.) Dosage x feedstock trials - Continuous maize without and with DAP fertilizer in agro-ecologies with field replicates over years - One time biochar (BC) application with different residues and low input rates No input Biochar NPK NPK + Biochar Location Climate Soil Biochar Siaya Embu Kwale Subhumid Subhumid Dry sub-humid haplic Acrisol umbric Nitisol ferric Acrisol Maize cobs Coffee husks Coconut shells Soil borne diseases - Common bean with combinations of mineral and/or organic inputs (inoculation, vermicompost, biochar) - Participatory trials with surveillance of root knot and rot infestations as well as yields

8 Long-term effects on crops

9 Long-term effects on crops!!!! Effect of sole biochar input on maize productivity decreases with time, but is sustained on soybean!!!! Significant elevation of maize fertilizer efficiency and soybean productivity over 8 growing seasons

10 Long-term effects on crops PRODUCTIVITY MAIZE SOYBEAN Comparison practices Yield difference (ton ha - ) Model error (ton ha - ) P value NPK vs No input <0.00 Biochar vs No input <0.00 NPK+Biochar vs No input. 0.9 <0.00 NPK vs Biochar NPK+Biochar vs Biochar <0.00 NPK+Biochar vs NPK <0.00 Yield difference (ton ha - ) Model error (ton ha - ) P value < VARIABILITY MAIZE SOYBEAN Practice Absolute yield variance (ton ha - ) Proportional yield variance (%) No input NPK Biochar NPK+Biochar.09.5 Residual variance.9 Absolute yield variance (ton ha - ) Proportional yield variance (%)

11 Long-term effect on soil C NYABEDA SIAYA After 0 yrs After 0 yrs After 0 years of continuous cropping biochar input of 00 ton ha -!! increased the carbon (C) content of topsoils by to 5 per mille!! as compared to where solely NPK fertilizers were applied.

12 Long-term effect on soil C NYABEDA SIAYA After 0 yrs After 0 yrs After 0 years of continuous cropping biochar input of 00 ton ha -!! increased the carbon (C) content of topsoils by 7 to 0 per mille!! as compared to the start of the trials.

13 Maize grain yield (ton ha - ) Dosage x feedstock effects Maize grain yield (ton ha - ) Maize grain yield (ton ha - ) SIAYA NP+0t BC SR NP+5t BC NP+t BC NP No input Dose responses are different for!!!! agro-ecosystems x feedstocks EMBU NP+0t BC NP+5t BC 7 NP+t BC 6 KWALE NP+0t BC NP 5 NP+5t BC No input 4 0 SR 06 NP+t BC NP No input 0 06

14 Maize grain yield (ton ha - ) Dosage x feedstock effects Maize grain yield (ton ha - ) Maize grain yield (ton ha - ) WESTERN 7 6 NP+0t BC SR NP+5t BC NP+t BC NP No input CENTRAL NP+0t BC NP+5t BC NP+t BC 7 6 EASTERN NP+0t BC NP 5 NP+5t BC No input 4 0 SR Input of 5 ton biochar ha - leads to sustained!!!! doubling/tripling of fertilizer efficiency 06 0 NP+t BC NP No input 06

15 Maize grain yield (ton ha - ) Dosage x feedstock effects Maize grain yield (ton ha - ) Maize grain yield (ton ha - ) WESTERN 7 6 NP+0t BC SR NP+5t BC NP+t BC NP No input CENTRAL NP+0t BC NP+5t BC NP+t BC 7 6 EASTERN NP+0t BC NP 5 NP+5t BC No input 4 0 Biochar inputs of 0 ton ha - render maize cropping, under normal rainfall, SR!!!! very productive and profitable NP+t BC NP No input 06

16 Effects on common bean PRODUCTIVITY NEMATODES FUNGAL ROT

17 Research gasifier sytems Sensors fitted in hood-airflow-tube system with a suction fan. Standard water boiling tests with different stoves and feedstocks (4-6 replicates)

Research gasifier sytems MASS BALANCE AND EMISSIONS Gasifier cook stove uses 6% (RH) to 40% (CS) less wood than emits 4% (CS) to %(RH) less CO than emits 67% (CS) to 8% (RH) less PM than emits 8%(CS)

18 Research gasifier sytems MASS BALANCE AND EMISSIONS Gasifier cook stove uses 6% (RH) to 40% (CS) less wood than emits 4% (CS) to %(RH) less CO than emits 67% (CS) to 8% (RH) less PM than emits 8%(CS) to 8% (RH) less CO than Window for low carbon futures Three-stone fire Gasifier x Rice Husks (n=6) Gasifier x Coconut shells (n=6) Three-stone (n=4) Wood fuel (g) 4 ± 6 9 ± ± 97 Residue fuel (g) NA Biochar yield (g) 4 ± 5 (55-60%) 555 ± 6 ( - 4%) NA

19 Research gasifier sytems USER EXPERIENCES Source: Njenga et al., 06

Way forward Access to climate finance for households and businesses through mitigation of emissions by use of gasifier systems and biochar inputs to soils Scale existing technologies and offset

20 Way forward Access to climate finance for households and businesses through mitigation of emissions by use of gasifier systems and biochar inputs to soils Scale existing technologies and offset protocols Develop framework for tracking and monetization (cfr. REDD soils) Decision support tools for biochar management in African farming systems Map biochar qualities from gasifier systems Tailor practices that sustainably increase productivity and resilience of crops

21 Thank you!! Questions?? Partners: Funding:

Biochar and Food, Water and Energy NEXUS

Biochar and Food, Water and Energy NEXUS International Workshop: Sustainable Rural Bioenergy Solutions in Africa, World Agroforestry Center (ICRAF) International Conference Room, 19 th January, 2018 Veronica