Presentation on theme: "Designing biochar types to modify selective soil properties USDA United States Department of Agriculture USDA-ARS GRACEnet program Isabel Lima (ARS-NO)-preparation."— Presentation transcript:
Designing biochar types to modify selective soil properties USDA United States Department of Agriculture USDA-ARS GRACEnet program Isabel Lima (ARS-NO)-preparation and characterization of biochar Warren Busscher (ARS-Florence)-soil hydraulics Harry Schomberg (ARS-Watkinsville)-soil N transformations Christoph Steiner (UGA)-preparation and characterization of biochar Julia Gaskin (UGA)-preparation of biochar and MBC KC Das (UGA)-preparation of biochar and properties Mohamed Ahmenda (NC A&T)-preparation of biochar Djaafar Rehrah (NC A&T)-preparation of biochar and characterization SunYoung Bae (NC A&T)-biochar hydrophilic/hydrophobic properties Baoshan Xing (UM-A)-13C NMR & IR characterization of biochar Thomas Ducey (ARS-Florence)-soil microbial population dynamics Jim Reeves (ARS-Beltsville)-NIR characterization of biochar and soils Don Watts (ARS-Florence)-experimental set up and measurements John Loughrin (ARS-Bowling Green)-biochar sorption of pollutants Jeff Novak, USDA-ARS-CPRC Northeast Biochar Symposium November 13, 2009
Physiography of SE USA Coastal Plain In the SE Coastal Plain, most of the agricultural soils formed in fluvial and marine sediments deposited 0.5 to 5 million yrs ago. The soils are sandy with poor fertility, acidic pH values, and low soil organic carbon contents (SOC). Piedmont Coastal Plain 19.1 million acres in SC and about 12.8 million of total land area is in the Coastal Plain (Pam Thomas, SC NRCS)
Soil association across a SC Coastal Plain landscape Coxville Norfolk Bonneau Paired Field at PDREC, Florence SC Deep coring at Paired Field Sandy soils used for agriculture have low to very low %SOC contents with profile depth. How can we increase their potential to sequester more OC in the profile?
Rebuilding SOC using tillage and crop management practices Conservation tillage effect to sequester C was depth dependent. In a 6 year corn + cotton rotation, about 15 Mg OC/ha were returned to sandy soils (Novak et al., 2009). The SOC increased by only 0.51% at 0-3 cm depth (< 4% of total residue OC).
Agents to sequester soil OC and lower CO 2 Conservation tillage (low results) C uptake by vegetation (forests) C feedstock for biochar, biofuel, syn- gas manufacture (new) Conservation tillageBiochar from pine
What is biochar? Biochar is a charcoal-like product manufactured in ovens under low/high temperatures, pressures and moisture. It can be made from various organic feedstock’s (plants, manure, byproducts, etc.). Feedstock is subject to pyrolysis (under N 2 ) using fast or slow conditions. Biochar oven at NC A&T Biochar oven at UGA
Advantages of C capture as biochar Liming agent Nutrient source Binds Al Energy source Increases SOC contents Improves soil WHC Lasts for millennia? Pecan shells Pecan biochar in soil Gin trash biochar
Incubated a high T (700º C) pecan-shell biochar (BC) in a Norfolk for 67 d. ● High aromatic character (58%), high OC content (88%), and low amount of functional groups. ● Biochar (0, 0.5, 1 and 2%) was mixed into soil and then leached 2X with di. H2O. ● Measured soil chemical and leachate characteristics. 13 C NMR spectra of pecan biochar Early study (2008) days0 daysSoil + BC (%) % SOC contents Novak et al., Soil Sci. 2009
Designer biochar incubation in soil (2009) Biochar chemical production process and feedstock choice can be planned to create designer biochar that has specific chemical characteristics allowing for more C sequestration and improvement of selective chemical and/or physical issues of sandy Coastal Plain soils. Switchgrass feedstock Pyrolyzer Designer biochar Designer biochar in soil (2%) Soil Incubation for up to 128 d.
Table 1. Biochar recoveries, volatile matter, pH, and surface area measurements (Novak et al., in review) Feedstock Pyrolysis (ºC) C recovered (%) Volatile Matter (%) pH Surface area (m 2 g -1 ) Peanut hull Pecan shell Poultry litter Switchgrass CQuestFlash
Table 3. Mean pH and Mehlich 1 extractable P and Na concentrations in a Norfolk loamy sand at 0 and 128 d † of incubation with different biochar-types (Novak et al, in review). Soil + biocharPyrolysis (Cº)Incubation (d)pHP (lb/a)Na (lb/a) Soil alone Poultry litter Poultry litter CQuest Flash † Soil treatments were leached 4X with di. H 2 O between 0 and 128 d of incubation.
Moisture contents (w w -1 ) of Norfolk loamy sand after biochar additions and leaching with di. water
Table 4. Mean % soil moisture contents † in a Norfolk loamy sand treated with different biochar types (n = 4). % Soil moisture (w w -1 ) on day: Soil + biocharPyrolysis (Cº)02‡2‡ 6 Soil alone a9.6a Poultry litter a12.5b a10.4a Switchgrass b14.3b b19.9b CQuestFlash b14.1b † Soil treatments leached with 1.2 PV of di. H 2 O and leachate collected for 30 h. ‡ Tested using a multiple comparison test vs. control (Holm-Sidek method).
Conclusions: Higher pyrolysis temperatures resulted in lower biochar recoveries, greater surface area, pH, and ash contents. Biochars produced at higher pyrolysis temperatures increased soil pH, influenced N availability, and poultry litter biochar grossly increased Mehlich 1 [Na] and [P]. Water holding capacity varied after biochar incorporation. Biochars can be designed to have specific qualities that can target distinct properties in soils.