Wheat response to foliar-applied phosphorus is determined by soil phosphorus buffering

Authors

Raj Malik, Department of Primary Industries and Regional Development, Western AustraliaFollow
Craig Scanlan, Department of Primary Industries and Regional Development, Western AustraliaFollow
Andrew Van Burgel, Department of Primary Industries and Regional Development, Western AustraliaFollow
Balwinder Singh, Department of Primary Industries and Regional Development, Western AustraliaFollow

Document Type

Article

Publication Date

7-25-2024

Journal Title

Agronomy

ISSN

2073-4395

Keywords

wheat, foliar P, phosphoric acid, P rates, P timings, grain yield, agronomic efficiency, P use efficiency

Disciplines

Agricultural Science | Agronomy and Crop Sciences

Abstract

In no-till cropping systems, banding of phosphorus (P) fertiliser at seeding results in low use efficiency due to chemical reactions in soil. Foliar P has the potential to allow grain producers to respond tactically with P application after sowing when P supply from soil and fertiliser is not meeting crop demand. The objective of this study was to evaluate the effectiveness of foliar P on wheat grain yield, grain quality, biomass yield, P uptake and P use efficiency indices. Nine field experiments were conducted to investigate the response of wheat to foliar P. Three rates of P, 0, 2.5 and 5.0 kg/ha, as phosphoric acid (H3PO4 85%) were applied to wheat at three different growth stages: first tiller emergence (Z21), first node detection (Z31) and flag leaf emergence (Z39). Grain yield responses ranging from 176 kg/ha to 505 kg/ha to foliar-applied P were observed in six out of nine experiments. The percent grain yield response to foliar P was negatively related to the P buffering index (PBI, 0–10 cm soil depth), which is attributed to greater sorption by soil of the foliar P at the higher PBI levels. Mean agronomic efficiency (AE) across the experiments was 111 kg/kg P but reached up to 232 kg/kg P. It was also evident that foliar P has the potential to improve P concentration in shoots and grains and increase P uptake but with no or minimal effect on grain quality. Our results suggest that a combination of tissue testing at the seedling stage and soil P buffering can be used to guide when foliar P application is likely to increase grain yield in wheat.

Recommended Citation

Malik, R, Scanlan, C, Van Burgel, A, and Singh, B. (2024), Wheat response to foliar-applied phosphorus is determined by soil phosphorus buffering. Agronomy, 14 (8), 1630.
https://library.dpird.wa.gov.au/fc_researchart/288