Soil bicarbonate-extractable P (Colwell-P) map of Queensland main grazing lands
There are maps of P availability in Queensland.
| Publication date: | 08 June 2022 |
| Project status: | Completed |
| Livestock species: | Grass-fed Cattle |
| Relevant regions: | Queensland |
|
Download Report
(2.3 MB)
|
|
Summary
Pasture agronomists in Queensland have highlighted that bicarbonate-extractable soil phosphorus (P) maps produced for Queensland are not of a suitable scale and needed to be updated to a finer resolution. Moreover, given the low availability of total soil P to plants, current total P maps provide limited information for agricultural purposes. Bicarbonate-extractable P is considered a more reliable test for plant available P. The aim of this project was to use Digital Soil Mapping (DSM) to produce a map of bicarbonate-extractable P levels in surface soils at a one-hectare pixel resolution of Queensland’s grazing lands.
Objectives
The aim of this project was to use Digital Soil Mapping (DSM) to produce a map of bicarbonate-extractable P levels in surface soils at a one-hectare pixel resolution of Queensland’s grazing lands.
Key findings
The final product is a raster map of predicted natural (unfertilised) surface soil bicarbonate-extractable P (and associated prediction uncertainty) of Queensland grazing land south of the Gulf and Cape York Natural Resource Management Regions.
The P map is considered a reasonable prediction of P at the subcatchment to property scale. It is useful for distinguishing areas of high P from low P. While the level of uncertainty is higher in areas of more fertile soils (with higher P variability), across the majority of the map, where P levels are lower, predictions are more accurate.
Benefits to industry
The knowledge from comprehensively mapping soil P throughout Queensland will assist with prioritising soil testing in areas of high uncertainty, and more accurately target investment in research and extension. For example, the maps produced in this project could be used to:
-Plan P supplementation across different landscapes to improve the productivity and profitability of grazing operations through enhanced P management.
-Prioritise and concentrate soil testing efforts in areas with high uncertainty.
-Prioritise the introduction of Stylos and Leucaena or other leguminous pasture species in areas with sufficient natural P to maintain growth.
-Identify areas where inadvertent mining of soil native P might be occurring.
-Identify the areas most suitable for hosting field experiments on soil P dynamics.
-Raise awareness of the P cycle and soil P deficiencies in Queensland grazing systems.
Future research
The outcomes of this project emphasise the importance of the availability of improved P maps for the red meat industry, and will assist in prioritising areas for research and extension.
|
For More Information Contact Project Manager:Lindsey Perry E: reports@mla.com.au |
