USDA ARS Symposium 2021
Applying biochar to soil: Is it worth the expense? Jeff Novak, USDA-ARS-CPRC Northeast Biochar Symposium November 13, 2009 USDA United States Department.
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Presentation on theme: “Applying biochar to soil: Is it worth the expense? Jeff Novak, USDA-ARS-CPRC Northeast Biochar Symposium November 13, 2009 USDA United States Department.”— Presentation transcript:
1 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
2 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
3 Biochar reactions in soils: C cycle CO 2 (g) DOC H 2 O leaching Biochar in soil
4 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). Norfolk soil + %BC%SOC† Cumulative CO 2 flux µmol m 2 s -1 Leachate DOC mg L -1 01.75a22.8a28.3a 0.51.83b20.8a30.1a 1.02.20c20.9a33.0a 2.02.92d14.5a43.9a † Values are means from n = 3 and tested for significances using an ANOVA (Novak et al. accepted for publication in Geoderma).
5 Biochar reactions in soils: N cycle H 2 O leaching Drying and removal from columns NO 3 -N Soil total N (%TN)
6 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 ) 00.123a28.3a 0.50.130a30.1a 1.00.107a33.0a 2.00.120a43.9a † Values are means from n = 3 and tested for significances using an ANOVA (Novak et al. accepted for publication in Geoderma).
7 Nutrients released from soil + pecan biochar: After 67 d incubation Norfolk soil + % biochar Soil property00.51.02.0 pH5.2a5.6b5.9c6.4d K (mg kg -1 )26a47b49c69d Ca (mg kg -1 )392a462b537c692d CEC (cmol c kg -1 )5.2a5.4a5.6a5.9a Ex. Acid (cmol c kg -1 )2.4a2.1a2.0a1.5b
8 Improvements in soil physical properties after adding biochar 1.2 PV of di. H 2 0 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 Soil water holding capacity (WHC) determined by weight
10 Biochar movement into soils Biochar added to Ap horizon Biochar also needed in the E horizon Pecan shell biochar and Norfolk (before mixing into soil) Pecan shell biochar and Norfolk (after mixing into soil)
11 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)
12 Biochar leaching experiment Column packed with Norfolk E Norfolk Ap/E ± biochar leached with di. H 2 O Column cut in 1/2 Dark bands are leached biochar
13 DOC (g) collected from biochar (BC) treatments (Novak and Busscher, unpublished data) Norfolk Ap/E Soil + biochar DOC (g) Mean*SD Control (no BC)4.67a1.71 BC 12.24a0.83 BC 21.53a1.63 BC 329.82b10.51 LSD (0.05)11.51
14 Biochar applications to soil Biochar applied to field Manure feedstock pelletizer Raw Pellets Pyrolyzer Pelletized biochar (From Dynamotive)
15 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 application; »Is it worth it? Just ask Jeff!