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ARS Home » Pacific West Area » Corvallis, Oregon » Forage Seed and Cereal Research Unit » Research » Publications at this Location » Publication #311053
Title: Biochars derived from gasified feedstocks increase the growth and improve the nutrient acquisition of Triticum aestivum (L.) grown in agricultural alfisols

Author
item Trippe, Kristin
item Griffith, Stephen
item Banowetz, Gary
item Whittaker, Gerald

Submitted to: Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/12/2015
Publication Date: 8/19/2015
Citation: Trippe, K.M., Griffith, S.M., Banowetz, G.M., Whittaker, G.W. 2015. Biochars derived from gasified feedstocks increase the growth and improve the nutrient acquisition of Triticum aestivum (L.) grown in agricultural alfisols. Agriculture. 5:668-681. doi: 10.3390/agriculture5030668.

Interpretive Summary: The utility of biochars produced by biomass gasification for remediation of acidic production soils and plant growth in general is not as well known compared to effects from biochars resulting from pyrolysis. Our recent characterization of biochars produced from gasification of Kentucky bluegrass (Poa pratensis L.) seed screenings (KB) and wood conifer tree tops suggested that both may have utility in remediation of acid farm soils where crop yield is diminished from aluminum toxicity. Farmers routinely use lime to raise soil pH to minimize Al toxicity and optimize plant nutrient use. We reasoned that by virtue of its alkaline pH, KB biochar would act as a “liming” agent and also provide minerals and nutrients for plant growth. The findings presented in this report are the first showing the effects of KB biochar produced by gasification on the growth of wheat. Wheat grown in soil amended with either biochar showed a dramatic increase in growth with increasing biochar concentrations. Mineral nutrition was significantly enhanced, most likely due to remediation of the acid soils to more optimum pH levels. The pH adjustment also helped immobilize soil Al and reduced Al uptake and the associated effects on plant growth frequently observed in acidic soils. Selective binding of some ions, including heavy metals and possibly organics, and the capacity to alter acid soil pH could also provide value in acid soil remediation at active and abandoned mine sites where re-vegetation projects are challenged by harsh soil conditions that inhibit plant establishment and growth. The production and sale of biochar products provide potential added value to operations that generate plant biomass like the feedstocks used in this study. The use of these renewable co-products to produce bioenergy and a marketable biochar product may provide environmental and economic benefits to farming and wood product operations.

Technical Abstract: The utility of biochars produced by biomass gasification for remediation of acidic production soils and plant growth in general is not as well known compared to effects from biochars resulting from pyrolysis. Our recent characterization of biochars produced from gasification of Kentucky bluegrass (Poa pratensis L.) seed screenings (KB) and wood conifer tree tops suggested that both may have utility in remediation of acid farm soils where crop yield is diminished from aluminum toxicity. Farmers routinely use lime to raise soil pH to minimize Al toxicity and optimize plant nutrient use. We reasoned that by virtue of its alkaline pH, KB biochar would act as a “liming” agent and also provide minerals and nutrients for plant growth. A replicated greenhouse pot study was conducted in which single plants of wheat (Triticum aestivum L.) were grown for 74 d in 650 cm3 black plastic pots. Pots contained either a Freeman or Bernhill soil (acidic farm soils, Spokane County, WA, U.S.A) amended with either wood or KB biochar. Due to slight differences in the densities of the two biochars, the resulting experimental final mass concentrations of the KB product to soil was 0, 4, 12, 25, and 58 g kg-1 while those used for wood biochar were 0, 7, 17, 37, and 86 g kg-1. The KB biochar was produced at in a modified entrained flow gasifier at 650 to 700°C while the wood biochar was produced in a downdraft gasifier at 1100 to 1400°C. Both biochars were effective in creating soil conditions conducive to enhanced wheat growth relative to that of untreated soils. This represents the first evidence of the use of KB seed screenings biochar on plant growth. Plant mineral nutrition was significantly enhanced, most likely due to the increase in soil pH and enhanced quantities of plant nutrients provided by the biochar. Roots grown in biochar-amended soils had less Al accumulation compared to untreated soil and plant uptake of Ca was reduced. Wood and KB biochar had similar effects on wheat growth and plant nutrition in these experiments.