La Trobe
2017 Qiao STOTEN 603-604,416.pdf (1.1 MB)
Download file

Improving soil nutrient availability increases carbon rhizodeposition under maize and soybean in Mollisols

Download (1.1 MB)
journal contribution
posted on 07.01.2021, 02:52 by Yunfa Qiao, Shujie Miao, Xiaozeng Han, Shuping Yue, Caixian TangCaixian Tang
© 2017 Elsevier B.V. Rhizodeposited carbon (C) is an important source of soil organic C, and plays an important role in the C cycle in the soil-plant-atmosphere continuum. However, interactive effects of plant species and soil nutrient availability on C rhizodeposition remain unclear. This experiment examined the effect of soil nutrient availability on C rhizodeposition of C4 maize and C3 soybean with contrasting photosynthetic capacity. The soils (Mollisols) were collected from three treatments of no fertilizer (Control), inorganic fertilizer only (NPK), and NPK plus organic manure (NPKM) in a 24-year fertilization field trial. The plants were labelled with 13C at the vegetative and reproductive stages. The 13C abundance of shoots, roots and soil were quantified at 0, 7 days after 13C labelling, and at maturity. Increasing soil nutrient availability enhanced the C rhizodeposition due to the greater C fixation in shoots and distribution to roots and soil. The higher amount of averaged below-ground C allocated to soil resulted in greater specific rhizodeposited C from soybean than maize. Additional organic amendment further enhanced them. As a result, higher soil nutrient availability increased total soil organic C under both maize and soybean systems though there was no significant difference between the two crop systems. All these suggested that higher soil nutrient availability favors C rhizodeposition. Mean 80, 260 and 300 kg fixed C ha− 1 were estimated to transfer into soil in the Control, NPK and NPKM treatments, respectively, during one growing season.

History

Publication Date

01/01/2017

Journal

Science of The Total Environment

Volume

603-604

Article Number

C

Pagination

9p. (p. 416-424)

Publisher

Elsevier

ISSN

0048-9697

Rights Statement

The Author reserves all moral rights over the deposited text and must be credited if any re-use occurs. Documents deposited in OPAL are the Open Access versions of outputs published elsewhere. Changes resulting from the publishing process may therefore not be reflected in this document. The final published version may be obtained via the publisher’s DOI. Please note that additional copyright and access restrictions may apply to the published version.