A glasshouse study on the interaction of low mineral ash biochar with nitrogen in a sandy soil

Author(s)
Van Zwieten, Lukas
Kimber, S
Downie, A
Morris, S
Petty, S
Rust, J
Chan, K Y
Publication Date
2010
Abstract
The effect of a low mineral ash biochar on biomass production and nitrogen (N) uptake into plants was tested with wheat and radish in a Yellow Earth used for commercial vegetable production. The biochar had an acid neutralising capacity <0.5% CaCO₃, a total C content of 75%, and a molar H/C ratio of 0.45, indicating stability due to its aromaticity. A pot trial was established under climate-controlled conditions. Five rates of N fertiliser (0, 17, 44, 88, 177 kg N/ha) were applied as urea in combination with 5 biochar rates (0, 1.1, 2.2, 4.4, 11% w/w). Analysis of biomass production revealed a significant biochar × N fertiliser interaction. In particular, increasing biochar concentrations improved biomass production in both crop species at lower N application rates. The highest biochar application rate resulted in significantly greater accumulation of NO₃⁻-N in the soil and lower NH₄ ⁺-N averaged across the 5 N application rates. The biochar also decreased available P, and significantly increased microbial activity measured using the fluorescein diacetate method. Increasing N fertiliser application resulted in greater accumulation of NO₃⁻-N with no changes to NH₄ ⁺-N averaged across the 5 biochar application rates. Nitrogen fertiliser application did not influence microbial activity or biomass C. The trial suggests that in some cropping systems, biochar application will enable reduced N fertiliser input while maintaining productivity.
Citation
Australian Journal of Soil Research, 48(7), p. 569-576
ISSN
0004-9573
1446-568X
1838-6768
1838-675X
Link
Publisher
CSIRO Publishing
Title
A glasshouse study on the interaction of low mineral ash biochar with nitrogen in a sandy soil
Type of document
Journal Article
Entity Type
Publication

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