Soil Biological Responses to Biochar Amendments

Transcription

1 Soil Biological Responses to Biochar Amendments Janice E. Thies Crop and Soil Sciences Cornell University Midwest Biochar Conference August 2014

2 Proposed benefits of energy and biochar coproduction from biomass 2

3 How is the soil microbial community affected by the micro-environment on and around biochar? J. Grossman Live (green) Dead (red)

4 Variation among feedstocks is high and measurements change over time Characterization is critical Photo by M. Yamato

5 Characterizing biochar for soil use Downie, Joseph and Lehmann, 2009 Feedstock - physical and chemical properties Process Conditions - time temperature, activation Post Processing - ageing, oxidation, added nutrients Biochar physical and chemical properties Bulk density, surface area, porosity and pore size distribution CEC, ph, electrical conductivity C/H/O/N/P/S, Ash %, other elements Composition and % volatile organics Surface functional groups Distribution of mineral phases (surface and bulk) Solubility of organics and minerals 5

6 Biochars are not created equal

7 Biochars are not created equal

8 Soil quality and processes Root proliferation, Movement of soil organisms Aeration Water retention Water infiltration and transmission; erosion prevention Physical Biological Pest suppression N mineralization OM decomposition Habitat protection Chemical Nutrient retention and release N P, K, Ca, Mg, etc. micronutrients ph Energy (C) storage Salinity/Toxicity prevention

9 Model of potential interactions Microbes Inorganic nutrients Exoenzymes Soil organic matter

10 Soil microbial response metrics Abundance Microbial biomass PLFA qpcr Culturing Activity CO 2 evolution Other GHGs N cycling Soil enzymes Diversity PLFA Culturing T-RFLP Sequencing Constraints Adsorption

11 Biochar Amendment Soil Mixed samples Biochar particles Microbial respiration DNA extraction Exoenzyme activity Exoenzyme Localization Microbial biomass Exoenzyme dynamics Fungi 18S rrna PCR Bacterial 16S rrna PCR Microbial activity Microbial abundance T-RFLP Fingerprinting Microbial community composition

12 Adsorption of DOC on biochar and soil 54.0% 32.4% 12

13 Microbial Biomass C

14 Microbial abundance

15 qpcr of N cycling genes

16 CO2 evolution 16

17 Bulk soil Soil respiration Rhizosphere soil 17

18 Metabolic quotient Increased C use efficiency 18

19 Soil respiration in bulk soil at 5 years Cumulative CO 2 6 week incubation Accumulated CO2 (mg) Series1 Series2 Series3 Series4 Series5 Weeks

20 Bacterial diversity 24 months Bulk [12 & 30 t ha -1 ] Rhizosphere [0 and 1 t ha -1 ] 20

21 2007 vs. 2008

22 Microbial abundance (culturable and total microbial biomass) was higher in biochar-amended soils. Community composition of Bacteria, Archaea and fungi varied in relation presence or absence of biochar. Presence of roots and seasonal changes are also dominant drivers.

23 Fig. 4. AMMI analysis of bacterial community composition generated by T-RFLP after filtering noise and aligning T-RFs (Peaks) Rhizosphere 16S rdna (15.46%) Replicates Char (tons/ha) E1, E2, E3: 0 E4, E5, E6: 1 E7, E8, E9: 3 E10,E11,E12: 12 E13, E14: 30 E15 (27R 30 char): Data NA due to poor quality of T-RFLP. (19.18%)

24 Fig. 1. AMMI analysis of bacterial community composition generated by T-RFLP after filtering noise and aligning T-RFs (Peaks) (17.09%) Bulk soils 16S rrna Replicates Char (tons/ha) E1, E2: 0 E3, E4, E5, 1 E6, E7, E8: 3 E9, E10,E11: 12 E12, E13, E14: 30 8B (0 char): Data Not Available (NA) due to poor quality of T-RFLP. (27.30%)

25 Bulk vs Rhizosphere soil (20.19%) Bulk Rhizosphere Samples Char (t/ha) E1, E6: 0 E2, E7: 1 E3, E8: 3 E4, E9: 12 E5, E10: 30 (22.67%) AMMI analysis of bacterial community composition generated by T-RFLP (16S rrna genes)

26 Enzyme activities

27 Enzyme linked fluorescence Phosphatase activity β-d-glucuronidase activity 27

28 Enzyme linked fluorescence Biochar amended 3 hr 4 hr Unamended 4 hr Phosphatase β D glucuronidase Phosphatase 28

29 Summary of GeoChip operations A. GeoChip development Sequence retrieval B. Target preparation Environmental sampling DNA extraction & purification C. GeoChip analysis Array scanning & image analysis Data preprocessing Probe design and verification DNA amplification Target labeling Data normalization Array construction Array hybridization Statistical analysis He et al. (2011), FESEC.

30 GeoChip 4.0 The most comprehensive functional gene array Functional process No. of gene categories No. sequences retrieved No. of probes designed No. CDS covered Antibiotic resistance Bacterial phage Carbon degradation Carbon fixation Methane metabolism Nitrogen cycling Phosphorus utilization Stress Sulfur cycling Metal remediation Contaminant degradation Energy process Virulence Others ( gyrb, bchy) Total ,902 83, ,414

31 All samples Bulk and Rhizosphere Soil Rhizosphere soil Bulk soil

32 All Samples Biochar Applied 0, 3, 12,30 t ha -1

33 N cycling processes

34 Biological nitrogen fixation

35 Biological nitrogen fixation David Guerena

36 Biological nitrogen fixation David Guerena David Guerena

37

38 (1) Chemotaxis (2,3,4) Flavonoids (5) Aliphatic acids (6) Cytokinins (7) QS and attractants (8) Fatty acids (9) Proteins (10) Other secretions of unknown function

39 Sorption of signaling molecules blocks bioreactions Masiello et al

40 Reduced soil-borne disease Charcoal compost Control Yang et al.,

41 Future directions Develop a mechanistic understanding of Feedstock x pyrolysis conditions interactions and resultant effects on microbial responses over time in the field. How the unique properties of biochar, soil type and climate interact to influence the soil microbial community preserve soil fertility.

42 Acknowledgements Hongyan Jin Jin Su Kai Xue David Güereña Julie Grossman Johannes Lehmann