Applying biochar to soil Is it worth the

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Applying biochar to soil: Is it worth the expense? Jeff Novak, USDA-ARS-CPRC Northeast Biochar

Applying biochar to soil: Is it worth the expense? Jeff Novak, USDA-ARS-CPRC Northeast Biochar Symposium November 13, 2009 USDA United States Department of Agriculture USDA-ARS GRACEnet program

Outline: • Biochar reactions in soil (C and N cycles) • Nutrients released from

Outline: • Biochar reactions in soil (C and N cycles) • Nutrients released from biochars • Soil physical improvements after biochar addition • Biochar movement into soil • Biochar applications to soil a. particle b. pellets • Conclusions Pecan biochar enmeshed in the fabric of a Norfolk soil aggregate

Biochar reactions in soils: C cycle CO 2(g) Biochar in soil H 2 O

Biochar reactions in soils: C cycle CO 2(g) Biochar in soil H 2 O leaching DOC

Table 1. Mean %soil organic carbon (SOC) content, cumulative CO 2 fluxes and dissolved

Table 1. Mean %soil organic carbon (SOC) content, cumulative CO 2 fluxes and dissolved organic carbon concentration (DOC 0. 45µm) in water leachate from a Norfolk soil after 67 days of incubation with high temp pecan shell biochar (BC). Leachate DOC mg L-1 Norfolk soil + %BC %SOC† Cumulative CO 2 flux µmol m 2 s-1 0 1. 75 a 22. 8 a 28. 3 a 0. 5 1. 83 b 20. 8 a 30. 1 a 1. 0 2. 20 c 20. 9 a 33. 0 a 2. 0 2. 92 d 14. 5 a 43. 9 a †Values are means from n = 3 and tested for significances using an ANOVA (Novak et al. accepted for publication in Geoderma).

Biochar reactions in soils: N cycle Drying and removal from columns Soil total N

Biochar reactions in soils: N cycle Drying and removal from columns Soil total N (%TN) H 2 O leaching NO 3 -N

Table 2. Mean %soil total nitrogen (TN) content dissolved nitrate –N (NO 3 -N)

Table 2. Mean %soil total nitrogen (TN) content dissolved nitrate –N (NO 3 -N) concentration (0. 45µm) in water leachate from a Norfolk soil after 67 days of incubation with high temp pecan shell biochar (BC). Norfolk soil + %BC %TN† Leachate NO 3 -N (mg L-1) 0 0. 123 a 28. 3 a 0. 5 0. 130 a 30. 1 a 1. 0 0. 107 a 33. 0 a 2. 0 0. 120 a 43. 9 a †Values are means from n = 3 and tested for significances using an ANOVA (Novak et al. accepted for publication in Geoderma).

Nutrients released from soil + pecan biochar: After 67 d incubation Norfolk soil +

Nutrients released from soil + pecan biochar: After 67 d incubation Norfolk soil + % biochar Soil property 0 0. 5 1. 0 2. 0 p. H 5. 2 a 5. 6 b 5. 9 c 6. 4 d K (mg kg-1) 26 a 47 b 49 c 69 d Ca (mg kg-1) 392 a 462 b 537 c 692 d 5. 2 a 5. 4 a 5. 6 a 5. 9 a Ex. Acid (cmolc kg-1) 2. 4 a 2. 1 a 2. 0 a 1. 5 b CEC (cmolc kg-1)

Improvements in soil physical properties after adding biochar Soil water holding capacity (WHC) determined

Improvements in soil physical properties after adding biochar Soil water holding capacity (WHC) determined by weight 1. 2 PV of di. H 20 added to surface of each soil Water leachate collected over 30 hrs (covered to minimize evaporative losses) Water leachate weighted for chemical analyses and pots weighed daily

Biochar movement into soils Biochar added to Ap horizon Pecan shell biochar and Norfolk

Biochar movement into soils Biochar added to Ap horizon Pecan shell biochar and Norfolk (before mixing into soil) Pecan shell biochar and Norfolk (after mixing into soil) Biochar also needed in the E horizon

What we need to achieve is biochar in Ap and E horizons: • Biochar

What we need to achieve is biochar in Ap and E horizons: • Biochar that can be surface applied, disked in, and then migrates through soil into subsurface hard layers. • We believe that biochar may assist in aggregate formation. Norfolk Ap Norfolk E (hard layer)

Biochar leaching experiment Column packed with Norfolk E Column cut in 1/2 Norfolk Ap/E

Biochar leaching experiment Column packed with Norfolk E Column cut in 1/2 Norfolk Ap/E ± biochar leached with di. H 2 O Dark bands are leached biochar

DOC (g) collected from biochar (BC) treatments (Novak and Busscher, unpublished data) DOC (g)

DOC (g) collected from biochar (BC) treatments (Novak and Busscher, unpublished data) DOC (g) N o r f o l k A p / E Soil + biochar Mean* SD Control (no BC) 4. 67 a 1. 71 BC 1 2. 24 a 0. 83 BC 2 1. 53 a 1. 63 BC 3 29. 82 b 10. 51 LSD (0. 05) 11. 51

Biochar applications to soil Manure feedstock pelletizer Pyrolyzer Biochar applied to field Raw Pellets

Biochar applications to soil Manure feedstock pelletizer Pyrolyzer Biochar applied to field Raw Pellets (From Dynamotive) Pelletized biochar

Conclusions • Biochar adds C and nutrients to soils, influences the soil N cycle

Conclusions • Biochar adds C and nutrients to soils, influences the soil N cycle (+/-); • Some biochars can act like a liming agent and increase a soils WHC; • Biochars can move into soils; • Biochar processing for field Just ask Jeff! • application; » Is it worth it?