Consulta: creatorFacets:"Spokas, K.A."
Registros recuperados: 8
Data/hora: 01/06/2024 19:08:29

Physical Disintegration of Biochar: An Overlooked Process
Provedor de dados: 18
Autores: Spokas, K.A.; Novak, J.M.; Masiello, C.A.; Johnson, M.G.; Colosky, E.C.; Ippolito, J.A.; Trigo, C.
Data collected from both artificially and field (naturally) weathered biochar suggest that a potentially significant pathway of biochar disappearance is through physical breakdown of the biochar structure. Through scanning electron microscopy (SEM) we characterized this physical weathering which increased structural fractures and possessed higher numbers of liberated biochar fragments. This was hypothesized to be due to the graphitic sheet expansion accompanying water sorption coupled with comminution.  These fragments can be on the micro and nano-scale, but are still carbon-rich particles with no detectable alteration in the oxygen to carbon ratio of the original biochar. However, these particles are now easily dissolved and could be moved by...
Tipo: Article
Palavras-chave: Dissolved Organic Carbon (DOC).
Ano: 2014
URL: http://eprints.nwisrl.ars.usda.gov/1548/1/1502.pdf

Biochar elemental composition and factors influencing nutrient retention
Provedor de dados: 18
Autores: Ippolito, J.A.; Spokas, K.A.; Novak, J.M.; Lentz, R.D.; Cantrell, K.B.
Biochar is the carbonaceous solid byproduct of the thermochemical conversion of a carbon-bearing organic material, commonly high in cellulose, hemicelluloses, or lignin content, for the purposes of carbon sequestration and storage.  More specifically, the thermal conversion process known as pyrolysis occurs when carbon-containing substances are introduced to elevated temperatures in the absence of oxygen at varying residence times, yielding biochar.  Several pyrolysis techniques employed to produce biochar differ in the temperature of reaction and residence time in the reactor.  Different reactor residence times are described as slow (hours to days), fast (seconds to minutes), and flash (seconds).  Fast or flash pyrolysis typically occurs around 500oC with...
Tipo: Book Section
Palavras-chave: Fertility; Soil quality; Fertilizer.
Ano: 2015
URL: http://eprints.nwisrl.ars.usda.gov/1590/1/1547.pdf

Biochar and manure effects on nitrogen nutrition in silage corn
Provedor de dados: 18
Autores: Lentz, R.D.; Ippolito, J.A.; Spokas, K.A.
Aluminum-based water treatment residuals (Al-WTR) have a strong affinity to sorb phosphorus.  In a proof-of-concept greenhouse column study, Al-WTR was surface-applied at 0, 62, 124, and 248 Mg/ha to 15 cm of soil on top of 46 cm of sand; Al-WTR rates were estimated to capture 0, 10, 20, and 40 years of phosphorus from an urban watershed entering an engineered wetland in Boise, Idaho, USA.  Creeping red fescue (Festuca rubra) was established in all columns; one set of columns received no Al-WTR or plants.  After plant establishment, once per week over a 12-week period, ~1.0 pore volumes of ~0.20 mg phosphorus/L was added to each column.  Infiltration rates were measured, leachate was collected and analyzed for soluble phosphorus, and fescue yield,...
Tipo: Article
Palavras-chave: Chemistry; Soil quality.
Ano: 2015
URL: http://eprints.nwisrl.ars.usda.gov/1592/1/1550.pdf

Biochar and manure effects on net nitrogen mineralization and greenhouse gas emissions from calcareous soil under corn
Provedor de dados: 18
Autores: Lentz, R.D.; Ippolito, J.A.; Spokas, K.A.
Few multiyear field studies have examined the impacts of a one-time biochar application on net N mineralization and greenhouse gas emissions in an irrigated, calcareous soil; yet such applications are hypothesized as a means of sequestering atmospheric CO2 and improving soil quality.  We fall-applied four treatments, stockpiled dairy manure (42 Mg/ha dry wt.); hardwood-derived biochar (22.4 Mg/ha); combined biochar and manure; and no amendments (control).  Nitrogen fertilizer was applied in all plots and years based on treatment’s pre-season soil test N and crop requirements, and accounting for estimated N mineralized from added manure.  From 2009 to 2011 we measured greenhouse gas fluxes using vented chambers, net N mineralization (NNM) using buried bags,...
Tipo: Article
Palavras-chave: Corn; Manure; Chemistry; Nitrogen; Soil.
Ano: 2014
URL: http://eprints.nwisrl.ars.usda.gov/1558/1/1514.pdf

The effects of biochar and manure in silage corn
Provedor de dados: 18
Autores: Lentz, R.D.; Ippolito, J.A.; Spokas, K.A.
Amending soil with biochar may be a means of sequestering atmospheric CO2 and improving soil quality, but few multiyear field studies have examined the impacts of a one-time biochar application in an irrigated, calcareous soil. We fall-applied four treatments: dairy manure (18.7 tons/ac dry wt.); hardwood-derived biochar (10 tons/ac dry wt.); combined biochar and manure; and no amendments (control). We measured net N-mineralization using buried soil bags and soil greenhouse gas emissions (CO2, CH4, and N2O) from late spring to fall, corn silage yields, and crop N uptake each year. The influence of biochar and manure on silage yield changed with time after application in fall 2008. Biochar increased corn yields slightly (5%) in 2009, decreased yields by 14%...
Tipo: Article
Palavras-chave: Agricultural Soils; Manure Management; Calcareous soil; Soil quality; Soil.
Ano: 2015
URL: http://eprints.nwisrl.ars.usda.gov/1584/1/1540.pdf

Biochar Usage:  Pros and Cons
Provedor de dados: 18
Autores: Ippolito, J.A.; Lentz, R.D.; Novak M, J; Spokas, K.A.; Collins, H.P.; Streubel, J.
Soil fertility benefits of charcoal application have been reported as early as 1847 indicating that plant nutrients are sorbed within charcoal pores.  The use of biomass-derived black carbon or biochar, the solid byproduct from the pyrolysis processing of any organic feedstock, has garnered recent attention as a potential vehicle for carbon sequestration and a beneficial soil conditioner.  However, most of the past biochar research has focused on improving the physico-chemical properties of tropical (i.e. terra preta) and highly weathered soils, while little research has focused on improving arid or semi-arid soils of the USA.  Here, we present an overview of the potential benefits and drawbacks of biochar usage in western US agro-ecosystems based on...
Tipo: Article
Palavras-chave: Soil quality; Nutrients.
Ano: 2011
URL: http://eprints.nwisrl.ars.usda.gov/1522/1/1484.pdf

Soil health, crop productivity, microbial transport, and mine spoil response to biochars
Provedor de dados: 18
Autores: Novak, J.M.; Ippolito, J.A.; Lentz, R.D.; Spokas, K.A.; Bolster, C.H.; Sistani, K.R.; Trippe, K.M.; Phillips, C.L.; Johnson, M.G.
Biochar is being evaluated by scientists from the United States Department of Agriculture (USDA) Agricultural Research Service (ARS) for its potential to sequester soil C, to improve soil health, and to increase crop yields.  ARS scientists from multiple locations such as Florence, SC, Kimberly, ID, Bowling Green, KY, Corvallis, OR, and St. Paul, MN, are conducting investigations with agronomic experiments at the laboratory, greenhouse, and field plot scales. To further expand biochars utility, ARS scientists have collaborated with United States Environmental Protection Agency (US EPA) investigators to reclaim mine-impacted soils. In the agronomic investigations, both positive and negative aspects of biochar application were revealed.  In some experiments,...
Tipo: Article
Palavras-chave: Fertility; Soil quality; Soil.
Ano: 2016
URL: http://eprints.nwisrl.ars.usda.gov/1621/1/1578.pdf

Manure and fertilizer effects on carbon balance and organic and inorganic carbon losses for an irrigated corn field
Provedor de dados: 18
Autores: Spokas, K.A.; Novak, J.M.; Masiello, C.A.; Johnson, M.G.; Colosky, E.C.; Ippolito\, J.A.
Data collected from both artificially and field (naturally) weathered biochar suggest that a potentially significant pathway of biochar disappearance is through physical breakdown of the biochar structure. Through scanning electron microscopy (SEM) we characterized this physical weathering which increased structural fractures and possessed higher numbers of liberated biochar fragments. This was hypothesized to be due to the graphitic sheet expansion accompanying water sorption coupled with comminution. These fragments can be on the micro and nano-scale, but are still carbon-rich particles with no detectable alteration in the oxygen to carbon ratio of the original biochar. However, these particles are now easily dissolved and could be moved by infiltration....
Tipo: Article
Palavras-chave: Soil.
Ano: 2014
URL: http://eprints.nwisrl.ars.usda.gov/1547/1/1502.pdf