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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #287603

Title: Chemical characterization of chars developed from thermochemical treatment of Kentucky bluegrass seed screenings

Author
item Griffith, Stephen
item Banowetz, Gary
item GADY, DAVID - Farm Power Inc

Submitted to: Chemosphere
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/6/2013
Publication Date: 3/31/2013
Citation: Griffith, S.M., Banowetz, G.M. 2013. Chemical characterization of chars developed from thermochemical treatment of Kentucky bluegrass seed screenings. Chemosphere. 92:1275-1279.

Interpretive Summary: Kentucky bluegrass seed screenings are used as a biofuel in a combustion reactor. The charcoal produced from the combustion could be recycled to a crop field as a soil amendment if chemical characterization determined that the charcoal did not have deleterious chemical or physical factors that might harm the environment, soil, crop growth, and yield. Previous studies have shown that charcoal from biofuel combustion have the potential to enhance soil quality by pH adjustment, mineral amendment, and improved soil porosity. The objective of this research was to characterize charcoal produced from Kentucky bluegrass seed mill screenings (KBss) by a small farm-scale gasification unit. Our results support the hypothesis that KBss char could be applied in a cropping system without toxic environmental consequences and serve multiple purposes, such as; recycling critical plant macro- and micro-nutrients back to existing cropland, enhance soil carbon sequestration, raise soil pH of acid soils, and improve water holding capacity. Crop trails need to be implemented to further test these hypotheses.

Technical Abstract: Char produced from the gasification of post-seed harvest Kentucky bluegrass residues could be recycled to a cropping system as a soil amendment if chemical characterization determined that the gasification process had not produced or concentrated deleterious chemical or physical factors that might harm the environment, crop growth or yield. Previous reports have shown that char derived from the pyrolysis of a variety of biomass feedstocks has potential to enhance soil quality by pH adjustment, mineral amendment, and improved soil porosity. The objective of this research was to characterize char produced from Kentucky bluegrass seed mill screenings (KBss) by a small-scale gasification unit, operated at temperatures between 600 to 650°C, with respect to polyaromatic hydrocarbons (PAHs), selected heavy metals, as well as other physical and chemical characteristics, and determine its suitability for agricultural application as a soil amendment. We report chemical and physical data characterizing char produced from KBss, an agricultural residue resulting from the post-harvest seed cleaning process. Our results support the hypothesis that KBss char could be applied in a cropping system without toxic environmental consequences and serve multiple purposes, such as; recycling critical plant macro- and micro-nutrients back to existing cropland, enhance soil carbon sequestration, raise soil pH of acid soils, and improve water holding capacity. Crop field trails need to be implemented to further test these hypotheses.