TITLE:
Characterization of Novel Torrefied Biomass and Biochar Amendments
AUTHORS:
Heather D. Baldi, Tyler L. Foster, Xiaoqing Shen, Sam E. Feagley, Fred E. Smeins, Dirk B. Hays, Russell W. Jessup
KEYWORDS:
Torrefaction, Biochar, Pyrolysis, Soil Amendment, Organic Nutrient Source
JOURNAL NAME:
Agricultural Sciences,
Vol.11 No.2,
February
17,
2020
ABSTRACT: Nutrient management is vital for food, feed, fiber, and fuel production. However, excessive application and loss (volatilization, leaching, run-off, etc.) of inorganic and organic sources of nutrients have detrimental environmental impacts, while increasing prices for petroleum-based and mined fertilizers further limit opportunities for their utilization in developing nations. This study evaluated a novel, alternative type of nutrient source through pretreatment processes of torrefaction and pyrolysis by converting high-biomass feedstocks into renewable soil amendments. Napiergrass (Pennisetum purpureum Schumach., [cv. Merkeron]) and pearl millet—napiergrass (Pennisetum glaucum [L.] R. Br. × P. purpureum Schumach.) (PMN) were converted under atmospheric pressure with minimal oxygen at 250°C and 400°C, ground to 1 millimeter (mm) and 2 mm particle sizes, and compared to urea in a full-season field trial and short-season nursery trial growing maize (Zea mays L.) and PMN for fertility response. When compared to urea in the field trial, the torrefied biomass amendment (TBA) and biochar had similar responses despite lower nitrogen (N) application rates. The nursery trial also produced equivalent responses from urea and TBA regardless of lower N application with the exception being phosphorus (P). Finally, maize and PMN had higher P uptake with the TBA in both trials.