Phosphorus uptake benefit for wheat following legume break crops in semi-arid Australian farming systems

Title
Phosphorus uptake benefit for wheat following legume break crops in semi-arid Australian farming systems
Publication Date
2019-04
Author(s)
Doolette, Ashlea
Armstrong, Roger
Tang, Caixian
Guppy, Chris
( author )
OrcID: https://orcid.org/0000-0001-7274-607X
Email: cguppy@une.edu.au
UNE Id une-id:cguppy
Mason, Sean
McNeill, Ann
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
Springer Netherlands
Place of publication
Netherlands
DOI
10.1007/s10705-019-09977-0
UNE publication id
une:1959.11/26716
Abstract
This field study assessed phosphorus dynamics (crop-P uptake, resin-extractable P in the root-zone, P mobilisation and microbial-P) in break crop-cereal rotation sequences at four Australian semi-arid field sites differing in soil P fertility. Phosphorus mobilisation (9–30 kg P ha⁻¹) was apparent under break crops, consistently under canola and peas at three sites with low soil P fertility (i.e. pre-sowing soil resin-extractable P < 20 mg P kg⁻¹). Enhanced biological cycling of P (i.e. increased microbial-P) was limited to a low P site in the break crop phase. Phosphorus content of break crop aboveground residues following grain removal was 1–7 kg P ha⁻¹; P input was greater (12–18 kg P ha⁻¹) where legumes were green/brown manured. Varied residue P input did not result in differences in resin-extractable or microbial-P in soil prior to sowing wheat. Phosphorus uptake was greater for wheat after legume break crops compared to continuous wheat (2.0–4.7 kg P ha⁻¹) at all sites, especially where crops were green/brown-manured (3.9–5.9 kg P ha⁻¹). Greater P uptake by wheat was associated with increased grain yield at three sites but was not significantly correlated with the quantity of P input from break crop residues at all four sites or with soil mineral nitrogen pre-sowing of wheat at three sites. Break crops can directly contribute to P resource-use efficiency by mobilising residual P from soil but the agronomic significance of P supply from break crop residues to a P uptake benefit for following wheat remains to be elucidated.
Link
Citation
Nutrient Cycling in Agroecosystems, 113(3), p. 247-266
ISSN
1573-0867
1385-1314
Start page
247
End page
266

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