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2017 Aye BFSO53,61.pdf (600.78 kB)

Residue addition and liming history interactively enhance mineralization of native organic carbon in acid soils

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journal contribution
posted on 06.01.2021, 01:01 by Nang Seng Aye, Clayton R Butterly, Peter Sale, Caixian Tang
© 2016, Springer-Verlag Berlin Heidelberg. Lime application is the most common method to improve crop production in acid soils and has been shown to change soil organic C content. However, the impact of liming history on the priming effect on soil organic C is not well understood. This study examined the effect of liming history on C priming in response to the addition of crop residues of different qualities. Soils with pH ranging from 4.7 to 7.4 were collected from two adjacent field experiments whereby lime was applied at different rates, 6 and 35 years ago. A 90-day incubation study was conducted by applying 13C-labelled wheat (C/N 42) and field-pea (C/N 29) residues at a rate of 5 g kg−1 soil. Residue application to soils yielded the positive priming effect in all pH levels with the magnitude of C priming being the greatest at initial soil pH 6.6. In comparison, the optimal pH for residue decomposition (7.3) was higher than that for priming. The overall priming effect was about 17% greater with field-pea than wheat residue. However, cumulative decomposition of added field-pea residue was 15% lower than that of wheat residue. Furthermore, C priming was greater in soils from the 35-year-old than the 6-year-old limed plots, indicating that a longer history of liming did not enhance the protection of indigenous C from mineralization. The results suggest that increases in soil pH by liming enhanced native C priming through greater microbial biomass and activity and that the magnitude and dynamics of the priming effect largely depended on residue quality and its consequent nutrient supply to decomposer organisms. The study implies that over-liming would likely have negative impacts on the long-term C sequestration.

History

Publication Date

01/01/2017

Journal

Biology and Fertility of Soils

Volume

53

Issue

1

Pagination

15p. (p. 61-75)

Publisher

Springer

ISSN

0178-2762

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