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Soil-plant nitrogen isotope composition and nitrogen cycling after biochar applications

journal contribution
posted on 12.05.2022, 00:34 by Leila Asadyar, Chengyuan XuChengyuan Xu, Helen M Wallace, Zhihong Xu, Frederique Reverchon, Shahla Hosseini Bai
Biochar has strong potential to improve nitrogen (N) use efficiency in both agricultural and horticultural systems. Biochar is usually co-applied with full rates of fertiliser. However, the extent to which N cycling can be affected after biochar application to meet plant N requirement remains uncertain. This study aimed to explore N cycling up to 2 years after biochar application. We applied pine woodchip biochar at 0, 10 and 30 t ha (B0, B10, B30, respectively) in a macadamia orchard and evaluated the N isotope composition (δ N) of soil, microbial biomass and macadamia leaves. Soil total N (TN) and inorganic N pools were also measured up to 2 years after biochar application. Biochar did not alter soil TN but soil NO -N increased at months 12 and 24 after biochar application. Soil NO -N concentrations were always over ideal levels of 15 μg g in B30 throughout the study. Stepwise regression indicated that foliar δ N decreases after biochar application were explained by increased NO -N concentrations in B30. Foliar TN and photosynthesis were not affected by biochar application. The soil in the high rate biochar plots had excess NO -N concentrations (over 30 μg g ) from month 20 onwards. Therefore, N fertiliser applications could be adjusted to prevent excessive N inputs and increase farm profitability. −1 15 − − −1 15 − − −1 3 3 3 3

History

Volume

28

Issue

6

Start Page

6684

End Page

6690

Number of Pages

7

eISSN

1614-7499

ISSN

0944-1344

Location

Germany

Publisher

Springer

Language

eng

Peer Reviewed

Yes

Open Access

No

Acceptance Date

25/09/2020

External Author Affiliations

Griffith University; Instituto de Ecología A.C. Mexico

Era Eligible

Yes

Medium

Print-Electronic

Journal

Environmental Science and Pollution Research