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Soil and Plant yield responses to biochar (BC) application on temperate soils. 1,2 Stefanie Kloss , 2 F. Zehetner, 1 B. Wimmer, 1 A. Watzinger, 2 S. Zechmeister-Boltenstern, 3 B. Kitzler, 4 M. Lauer, 2 M.H. Gerzabek, 1 G. Soja
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Soil and Plant yield responses to biochar (BC) application on temperate soils 1,2Stefanie Kloss, 2F. Zehetner, 1B. Wimmer, 1A. Watzinger, 2S. Zechmeister-Boltenstern, 3B. Kitzler, 4M. Lauer, 2M.H. Gerzabek, 1G. Soja 1 AIT Austrian Institute of Technology GmbH, Department for Health and Environment, Tulln, Austria. 2 University of Natural Resources and Life Sciences, Institute of Soil Research, Vienna, Austria 3 Federal Research and Training Centre for Forests, Natural Hazards and Landscape, Vienna, Austria 4Joanneum Research, Graz, Austria
outline • The Biochar Project • Experimental design/ research questions • Materials and Methods • Results and Discussion • Conclusion
The Biochar project “Biochar for Carbon Sequestration in Soils: Analysis of production, biological effects in the soil and economics” Cooperation of • University of Natural Resources and Life Sciences, Vienna (BOKU) • Austrian Institute of Technology, Tulln (AIT) • Federal Research and Training Center for Forests, Natural hazards and Landscape, Vienna (BFW) • Joanneum Research (Graz) • Project period: April 2010- March 2013
The Biochar project “Biochar for Carbon Sequestration in Soils: Analysis of production, biological effects in the soil and economics” Cooperation of • University of Natural Resources and Life Sciences, Vienna (BOKU) • Austrian Institute of Technology, Tulln (AIT), • Federal Research and Training Center for Forests, Natural hazards and Landscape, Vienna (BFW) • Joanneum Research (Graz) • Project period: April 2010- March 2013
The Biochar project Divided into 8 work packages Pyrolysis conditions and BC characterization Field- and pot trials Effects of BC on soil fertility and plant yield BIOCHAR BC for carbon sequestration (incubation experiment) Effects of BC on greenhouse gas emissions Effects on microbial communities in the soil Economical evaluation
The Biochar project Divided into 8 work packages Pyrolysis conditions and BC characterization Field- and pot trials Effects of BC on soil fertility and plant yield BIOCHAR BC for carbon sequestration (incubation experiment) Effects of BC on greenhouse gas emissions Effects on microbial communities in the soil Economical evaluation
Pot dimensions: height 40 cm / 16’’; Ø 23. 5cm / 9’’; siphon-like effluent to collect leachate water Pot trial: - 4 different biochars (Straw [525°C]; mixed woodchips [525°C], Vineyard pruning [400°C, 525°C]) at 2 BC concentrations (1 w.-% and 3 w.-%) - Crops: mustard (Sinapis Alba); Nov 23rd 2010– Feb 2nd, 2011 barley (Hordeum vulgare); Feb 18th – June 20th, 2011 red clover (Trifolium pratense); Jul 26th – Dec 13th, 2011 - N fertilization (0 bis 200 kg N ha-1; standard fertilization: 40 kg N ha-1 for mustard; 100 kg N ha-1 for barley) 125 pots (n=5) mustard barley
Pot trial: Austrian Institute of Technology, Tulln Start in November 2010 Three agricultural soils (0-30cm): Planosol, Cambisol, Chernozem GEOLOGY Bohemian Massif VIENNA Tertiary Planosol Tertiary- Quarternary Chernozem Cambisol
Investigated soil parameters: • pH • C/N • Electrical conductivity (EC) • cation exchange capacity (CEC) • Nitrogen supplying potential (anaerobic incubation; NSP in µg g-1 DM d-1) • “plant-available” P and K (Calcium Acetate Lactate/ CAL- extraction) Crop parameters: • Above ground biomass (g m-2) • elemental composition after digesting with HNO3: HClO4 = 20 + 4 mL • N concentration • Effect of different BC types on Planosol + crops • Effect of BC (woodchips) on different soil types and crops
Biochar Characterization pH El. conductivity VOC Cation exchange capacity C/N
Results Effects of different BCs on thePlanosol (after 7 months) pH CEC Significant increase of pH and CEC for all BC types on the sandy Planosol • Increase in P and K availability (esp. straw) phosphorus potassium No influence of pyrolysis temperature! (Second soil sampling)
Soil parameters Effects of woodchips BC (3%) on different soil types (after 7 months) pH CEC • Planosol showed most distinct reactions on BC application • (pH, CEC, P) P C/N (Second soil sampling)
Effect on crop yield Effects of different BC types (Planosol) • - Initially detrimental effect (except for straw!) • Effect of pyrolysis temperature • no statistical difference for clover What’s so special about straw biochar ???
Why so massive yield inhibitions? “BC application to soil increases osmotic potential due to Na and causes toxic effects” (Rajkovich et al., 2011) “BC application to soil causes N deficiency in plants” (Rondon et al., 2007; Collison et al., 2009,…) N concentration in mustard No or negligible N-immobilization ( + increased nitrogen suppyling potential) No toxic effect
Why so massive yield inhibitions? “pH increase may cause micronutrient deficiencies” (Marschner and Rengel, 2012) (mustard) Yield inhibitions caused by micronutrient deficiencies??? Does not explain straw BC Lower micronutrient content also present for the third crop clover that showed no decreased plant yield
Why so massive yield inhibitions? “pH increase may cause micronutrient deficiencies” (Marschner and Rengel, 2012) (mustard) Yield inhibitions caused by micronutrient deficiencies??? Mo Massive increase in Mo concentration in mustard after BC application Does not explain straw BC Lower micronutrient content also present for the third crop clover that showed no decreased plant yield
Why so massive yield inhibitions? • N-immobilization if yes, only short-term • toxic effects due to salt input highest salt input caused by straw BC • micronutrient deficiency likely, but probably not the only reason • Mo toxicity Mo concentration in straw was highest What’s left?
Why so massive yield inhibitions? Volatile organic compounds (VOC): “Depending on the amount of VOCs they may either have plant growth promoting or inhibiting properties” (Deenik et al., 2010; Spokas et al., 2011) “If effects are detrimental, it’s only temporary” (Deenik et al., 2011) Temporary effect consistent with our findings Straw BC apparently more favorable in terms of VOC content than any other BC
Why so massive yield inhibitions? Volatile organic compounds (VOC): “Depending on the amount of VOCs they may either have plant growth promoting or inhibiting properties” (Deenik et al., 2010; Spokas et al., 2011) “If effects are detrimental, it’s only temporary” (Deenik et al., 2011) VOC Temporary effect consistent with our findings Straw BC apparently more favorable in terms of VOC content than any other BC Lowest Volatile organic content found in Straw BC!
Why so massive yield inhibitions? Volatile organic compounds (VOC): “Depending on the amount of VOCs they may either have plant growth promoting or inhibiting properties” (Deenik et al., 2010; Spokas et al., 2011) “If effects are detrimental, it’s only temporary” (Deenik et al., 2011) Dry mass VOC Temporary effect consistent with our findings Straw BC apparently more favorable in terms of VOC content than any other BC Lowest Volatile organic content found in Straw BC!
Conclusion I • All BCs showed a liming effect • BC application to soil increased CEC, especially on the sandy Planosol with the originally lowest pH • All BCs increased P and K availability, especially wheat straw BC • no influence of pyrolysis temperature on soil parameters
Conclusion II • Plant yield was significantly inhibited by BC application except for Wheat straw BC • Plant yield was significantly influenced by pyrolysis temperature (higher pyrolysis temperature lower plant yield) • Wheat straw BC significantly increased plant yield of the second crop (barley) compared to control • C/N in the soil increased after BC application, but N immobilization may not play any or only a short-term role • Micronutrient deficiencies may be partly responsible for decreased plant yields, as well as VOCs
aCKNOWLEDGeMENTS Special thanks to... • The whole Biochar research team for their support • Akio Enders (Cornell University) • Austrian Research Promotion Agency (FFG)/ New Energies 2020 project number: 825438
Thank you for your attention! stefanie.kloss@boku.ac.at