Document Type
Article
Publication Date
12-16-2024
Journal Title
Crop & Pasture Science
ISSN
ISSN: 1836-0947, eISSN: 1836-5795
Keywords
Colwell P, DGT-P, fertiliser, PBI, phosphorus, rainfall, soil analysis, wheat
Disciplines
Agricultural Science | Agronomy and Crop Sciences
Abstract
Context
Current decision support systems (DSS) for phosphorus (P) fertiliser were developed using data from historical cropping systems. An understanding of how soil properties and rainfall influence wheat (Triticum aestivum) response to P fertiliser in current systems is required to optimise P management. Aims
The aims of this study were to: (1) assess the soil properties that have the greatest influence on relative yield; (2) examine how rainfall conditions influence relative yield; and (3) examine whether there were interactive effects between rainfall and soil properties on relative yield. Methods
Forty P rate-response field experiments were completed in Western Australia. Regression tree modelling, soil test calibration curves and the sliding window approach were used to examine relationships between soil properties or rainfall and relative yield. Key results
Phosphorus buffering index (PBI) was important for determining the factors that influence relative yield. For sites with PBI 0–10 cm <56 (n = 30), regression tree modelling showed rainfall before sowing and soil pHCa were important factors (R2 = 0.59). For sites where PBI >56 (n = 10), relative yield was closely related to plant-available P at 0–10 cm and the r-value for the calibration curve was 0.95. Conclusions
Rainfall and soil pHCa influence wheat response to P where PBI <56 is attributed to an accumulation of soil P after decades of fertiliser applications and the availability of stored soil P to crops. Implications
Pre-sowing rainfall should be included in DSS so that grain producers can make informed, tactical decisions about P fertiliser applications for wheat at sowing.
Recommended Citation
Scanlan Craig A., Malik Raj, Boitt Gustavo, Gherardi Mark, Easton James, Rengel Zed (2024) Phosphorus buffering determines how soil properties and rainfall influence wheat (Triticum aestivum) yield response to phosphorus fertiliser. Crop & Pasture Science 75, CP24295. https://doi.org/10.1071/CP24295