Biochar as a carrier medium to introduce fresh mycorrhizal inocula into plant root zones

Transcription

1 Biochar as a carrier medium to introduce fresh mycorrhizal inocula into plant root zones Don Graves, BSc, MSc (Hons) Plant Biology Nelson Bays Mycorrhizas 17 Wilkie street, Motueka, 7120, dgraves@ihug.co.nz Hypothesis: "Biochar granules can provide an affordable and renewable alternative to expanded clay minerals as a carrier medium to introduce fresh mycorrhizal inocula into plant root zones, particularly in biologically degraded field soils and in sterile nursery media."

2 Introduction to Mycorrhizas Mutually beneficial symbioses of roots & soil fungi 1. Bi-directional exchange of mineral nutrients & photosynthates between plants & mycorrhizal fungi 2. Increased soil volume available as a nutrient source & habitat to plant roots, soil fungi & microorganisms assosiated with mycorrhizosphere & rhizosphere

3 Mycorrhizal Fungi Characteristics Arburscular Mycorrhizal Fungi (AMF) Glomeromycota phylum 1. Asexual no fruiting bodies - mushrooms / puffballs / truffles physical distribution by root to root transfer, mechanical transport by animals, or soil erosion runoff 2. Obligate biotrophs must have living plant root hosts non saprotrophic 3. AMF populations reduced by: conventional tillage - burying & dilution of AMF non-host monocultures prolonged fallow / bare soil surfaces Ectomycorrhizas & Orchidaceous mycorrhizas - Basidiomycota & Ascomycota phyla Ericoid mycorrhizas Ascomycota phylum

4 Arbuscular Mycorrhizal Fungi (AMF) form endosymbiotic nutrient exchange structures within root cortical or epidemal cells Arbuscule = small tree-like fungal structure enclosed within a plant cell membrane

5 Mycorrhizal Plant Benefits 1. Plant health improved P nutrition increased photosynthesis disease resistance increased drought tolerance 2. Plant community composition / increased diversity increased net primary productivity increased soil Carbon deposition increased quality & quantity of litter from roots, fungi & soil microorganisms 3. Improved nutrient cycling less need for mineralisation of organic matter to produce soluble minerals inter-plant nutrient transfer / commensalism between plants sharing a common hyphal network

6 Mycorrhizal Soil Benefits Improved soil structure aka "sticky string bag" effect Soil macro-aggregates (>0.25mm diameter) 1. Physical - hyphae penetrate & align soil particles soil water regime wet / dry cycles enmeshment of soil particles & organic matter 2. Biochemical mechanisms - living mycelium products secreted into soil environment, (e.g. Glomalin) decomposition products of hyphae Soil micro-aggregates (<0.25mm diameter) Micro-biota / biological mechanisms Bacterial by-products glues & gums Fungal-derived soil organic carbon (SOC) has a longer residence time compared to bacteria-derived SOC or most plantderived SOC & hence increases soil carbon sequestration

7 Overview of hyphal mediated mechanisms that influence the formation & stabilisation of soil aggregates

8 Mycorrhizal inoculation methods 1. Direct transplants inoculated plants from field soils or pot cultures direct transfer of fresh field soils 2. Nursery production aeroponics 'pot-cultures' in planter bags inoculated seedling transplants * bulked-up inoculated potting media & roots for transplants or hydroseeding 3. On-farm inoculum production economically affordable for broad-acre applications locally adapted / 'eco-sourced' soil microorganisms raised bed production of inocula carrier media: Expanded clay + fresh field soil, roots or compost * Biochar granules * Synthetic Terra Preta

9 Mycorrhizal Interactions with Biochar Published research literature regarding concepts and mechanisms of mycorrhizal responses to biochar in soil was reviewed by Warnock et al in Evidence indicated that the mechanisms in which biochar may influence the abundance and function of mycorrhizas included: 1. alteration of soil physico-chemical properties including adsorption of labile minerals & organic molecules, > CO2, < ph improved soil structure - water-stable aggregates, aeration, drainage, 2. indirect effects on other soil microbes soil carbon deposition, particularly mycorrhizosphere & rhizosphere organic substrates suitable for soil bacteria and soil food web heterotrophic & saprotrophic organisms 3. plant-fungus signalling interference & detoxification of allelochemicals 4. provision of refugia from fungal grazers

10 Physical comparisons-vermiculite & BioChar Vermiculite expanded clay mineral layers provide protected habitats from potential soil dessication & predation Mycorrhizal hyphae growing from spore base invade into the charcoal pore with larger size (Ogawa, 1994)

11 Fine roots show affinity to biochar Photo by Rob Flanagan and Stephen Joseph (2008) Miller & Jastrow (1992) Schematic diagram of enmeshment of soil microaggregates by extraradical mycorrhizal hyphae to create the conditions for macroaggregate formation & stabilization within the rhizosphere

12 Proposed Biochar research aims: Investigate the commercial potential for use of biochar as a soil microbial carrier media for application in: 1. horticultural potting media, seedlings & plants 2. agronomic soils & crops 3. phyto-remediation of biologically degraded soils & soils with low levels of organic matter: Intensively tilled soils Desertified / salinated soils Mine soil reclamation & erosion control Road embankments Oil shale sands

13 Proposed Biochar research aims: Identify optimal size of biochar granules as microbial carrier media horticultural potting media banded application by no-tillage direct drilling, e.g. Cross-Slot

14 Proposed Biochar research aims: Compare effects of direct drilling equipment on the durability of: 1. expanded clay minerals (Vermiculite / Perlite / Zeolite) 2. uncoated biochar granules 3. coated (pelletised) biochar granules - clay emulsion or alginate coated 4. synthetic Terra Preta granules Cross Slot No-Tillage Systems Seed Drill

15 Proposed Biochar research aims: Compare biological effects resulting from mycorrhizal inocula: 1. expanded clay minerals (Vermiculite / Perlite / Zeolite) 2. uncoated biochar granules 3. coated (pelletised) biochar granules - clay emulsion or alginate coated 4. synthetic Terra Preta granules Fluoresent green stained Glomalin glycoprotein on soil aggregate, & Glomus mosseae AMF - Wright (2009)

16 Thanks & Acknowledgements The late Dr Neil Macgregor did ground-breaking work that laid the foundation for others to follow: soil biology & biochemistry, soil microbial ecology, microbial inoculants, microbial genetics, nutrient cycling, soil and water quality, land disposal of rural and urban waste, composting, organic and ecologically sustainable farming systems, livestock health, and the experimental use of reporter genes in soil microbial ecology studies Neil was more than an inspirational mentor, teacher & supervisor with a wry sense of humour, Neil also had broader concerns, including promotion & practice of socially responsible science & international development, ecological sustainability, the enablement of universal wellbeing & meaningful living. Dr John Baker, Bill Ritchie & their colleagues have pioneered leading edge conservation-tillage research & the subsequent commercial development of Cross-Slot No-tillage Systems, thus enabling the preservation & enhancement of soil & water quality, bringing life back to the soil Dr David Douds Jnr. & his colleagues at Rodale Institute & USDA have an ongoing commitment to the development of low-cost, low-tech technologies & accessible peer reviewed scientific information for on-farm mycorrhizal inocula production and utilization. Mycorrhizologists, researchers, practitioners & bloggers in tillage, biochar, cllimate change, soil quality & plant health included in references, as well as advice, analysis, insights, images, personal communications, encouragement & patient listening from many people including my good friend & wife Maria, Lyn Abbott, Mark Brundrett, Bob Crowder, Sandy Dickson, Robert Hill, Paula Jameson, Hella Jansen, Peter Long, Raymond Miller, David Read, Sally Smith, Katarzyna Turnau, Marcel Van der Heijden, Bryan Walker, Peter Winsley & many others

17 References & Further Reading Microbial inoculant production & utilisation for soil restoration & crop health Baker CJ Saxton KE, Ritchie WR, Chamen WCT, Reicosky DC, Ribero MFS, Justice SE, & Hobbs PR (2006) No-tillage Seeding in Conservation Agriculture (2 nd edn) Publ. by CAB International & FAO Brundrett M, Bougher N, Dell B, Grove T & Malajczuk (1996) Working With Mycorrhizas in Forestry and Agriculture, Publ. by Australian Centre for International Agriculture Research (ACIAR) Declerk S, Strullu D-G & Fortinn JA (2005) (eds) In Vitro Culture of Mycorrhizas, Publ. by Springer-Verlag Douds Jr DD, Nagahashi G, Pfeffer PE, Kayser WM, and Reider C (2005) On-farm production and utilisation of arbuscular mycorrhizal fungus inoculum Canadian Journal of Plant Science Vol 85, 1, pp Douds Jr DD, Nagahashi G & Hepperly PR (2010) On-farm production of inoculum of indigenous arbuscular mycorrhizal fungi and assessment of diluents of compost for inoculum production Bioresource Technology Vol 101, Issue 7 pp Flanagan R & Joseph S (2008) Hammes K & Scmidt MWI (2009) Changes of Biochar in Soil in Lehmann J & Joseph S (eds) Biochar Environmental Management, Science & Technology, Chapter 10, pp Haselwandter K (2000) Soil Microorganisms, Mycorrhizas, and Restoration Ecology Ch.5 pp , in Restoration Ecology and Sustainable Development K.M. Urbanska, N.R. Webb, N. Webb & P.J. Edwards. (Editors) Publ. by Cambridge University Press. Hill R & Browlie M (2009) Enhancing Pinus radiata health and vigour using beneficial microbes and natural products, Research report commissioned by the Forest Biosecurity Research Council, Funding period July 2008 June 2009, Jeffries P, Gianinazzi S, Perotto S, Turnau K & Barea J-M (2003) The Contribution of Arbuscular Mycorrhizal Fungi in Sustainable Maintenance of Plant Health and Soil Fertility (Review) in Biological Fertility of Soils, Vol. 37, No. 1, pp Malajczuk N, Reddell P, & Brundrett M (1994) Role of Ectomycorrhizal Fungi Minesite Reclamation pp , in Pfleger FL & Linderman RG (Eds) Mycorrhizae and Plant Health Publ. By The American Phytopathological Press, St Paul, Minnesota Nishio M (1996) Microbial Fertilizers in Japan. Ogawa M (1994) Symbiosis of people and nature in the tropics, in Farming Japan 28(5): pp Ogawa M (1998) Utilization of symbiotic microorganisms & charcoal for desert greening, in Green Age 14: pp Rooney DC, Killham K, Bending GD, Baggs E, Weih M, & Hodge A (2009) Mycorrhizas and biomass crops: opportunities for future sustainable development, review in Trends in Plant Science Vol.14 No.10, pp Sylvia DM, Fuhrmann JF, Hartel PG & Zuberer DA (1999) Principles and Applications of Soil Microbiology Publ. by Prentice Hall Theis JE & Rillig MC (2009) Characteristics of Biochar: Biological Properties in Lehmann J & Joseph S (eds) Biochar Environmental Management, Science & Technology, Chapter 6, pp Van der Heijden MGA (2008) The unseen majority: soil microbes as drivers of plant diversity and productivity in terrestrial ecosystems Review & Synthesis in Ecology Letters, (2008) vol.11 pp

18 References & Further Reading Mycorrhizas, soil structure and soil carbon sequestration Blackwell P, Riethmuller G & Collins M (2009) Biochar Application to Soil in Lehmann J & Joseph S (eds) Biochar Environmental Management, Science & Technology, Chapter 12, pp Camps (2009) Biochar and Microbial Activity in Learning from Nature for Sequestering Carbon in Soil Carbonization and Biochar, New Zealand Biochar Research Centre, Massey University, pp , Chia CH, Joseph S, Munroe P, Lin Y, A Downie A, van Zweiten L, Kimber S, Cowie A, Singh BP, Lehmann J, Hanley K, Blackwell P, & Carter E (2009) Development of Synthetic Terra Preta (STP): Characterisation and Initial Research Findings Clapperton MJ, Yin Chan K, & Larney FJ (2003) Managing the Soil Habitat for Enhanced Biological Fertility in Abbott LK & Murphy DV Soil Biological Fertility: A key to sustainable land use in agriculture, Chapter 10, pp , Kluwer Publications, Douds Jr DD, Pfeffer PE 7 Shachar-Hill Y (2000) Carbon partioning, cost, & metabolism of arbuscular mycorrhizas. In Kapulnik Y & Douds Jr Dd (eds) 2000 Arbuscular Mycorrhizas: Physiology & Function. Chapter 6, pp , Kluwer Publications. Douds Jr DD, Johnson NC (2003) Contributions of Arbuscular Mycorrhizas to Soil Biological Fertility in Abbott LK & Murphy DV Soil Biological Fertility: A key to sustainable land use in agriculture, Kluwer Publications, Chapter 7, pp Jastrow JD, Amonette JE, & Bailey VL (2007) Mechanisms controlling soil carbon turnover and their potential application for enhancing carbon sequestration Climatic Change (2007) Vol 80 pp Kabir Z (2005) Tillage or No-tillage: impact on Mycorrhizae, in Canadian Journal of Plant Science Vol 85, pp23-29 Miller RM, Jastrow JD (1992) The Role of Mycorrhizal Fungi in Soil Conservation in Bethlenfalvay GJ & Lindermann RG (eds) Mycorrhizae in Sustainable Agriculture, ASA Special Publication # 54, Chapter 2, pp Miller RM, Jastrow JD (2000) Mycorrhizal fungi influence soil structure. In: Kapulnik Y, Douds DD Jr (eds) Arbuscular mycorrhizas: physiology and function. Kluwer, Dordrecht, The Netherlands, pp 3 18 Rillig MC & Mummey DL (2006) Mycorrhizas and Soil Structure New Phytologist, Tansley Review Vol 171, 1, pp Simpson RT, Frey SD, Six J & Thiet RK (2004) Preferential Accumulation of Microbial Carbon in Aggregate Structures of No-Tillage Soils, in Soil Science Society of America Journal, Vol. 68, pp Six J, Feller C, Denef K, Ogle SM, de Moraes JC, & Slbrecht A (2002) Soil organic matter, biota and aggregation in temperate & tropical soils Effects of no-tillage, Review in Agronomie Vol 22 pp Smith SE & Read DJ (2008) Mycorrhizas in Agriculture, Horticulture and Forestry in Mycorhizal Symbiosis 3 rd Editition, Academic Press, Chapter 17, pp Sohi S, Lopez-Capel E, Krull E & Bol R (2009) Biochar, climate change & soil: A review to guide future research. Published by CSIRO Land & Water Science Report series ISSN: Wardle DA (2002) Communities & Ecosystems Linking the Aboveground & Belowground Components, Monographs on Population Biology #34, Princeton University Press. Warnock DD, Lehmann J, Kuyper TW & Rillig MC (2007) Mycorrhizal responses to biochar in soil concepts & mechanisms, in Plant & Soil, Vol 300 pp Winsley P (2007) Biochar and bioenergy production for climate change mitigation New Zealand Science Review Vol 64 (1) pp Woolf D (2008) Biochar as a soil amendment: A review of the environmental implications Wright S (2009) Analysis of Glomalin. INVAM (International Culture Collection of (Vesicular) Arbuscular Mycorrhizal Fungi