Researcher(s) |
Nicole Dimos (SPAA) Chris Hunt (SPAA) Michael Moodie (MSF) |
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Year(s) | 2010 |
Contributor | Society of Precision Agriculture Australia |
Trial location(s) |
Mildura, VIC
|
To use PA maps to indentify and sample soil zones within a paddock. To investigate soil phosphorus levels in different soil types with a paddock. To see if altering fertiliser rates at sowing has an impact on grain yield.
There has been widespread use of continuous cereal in the Mallee over the past decade, and with many drought years throughout this period fertiliser inputs have generally been greater than crop demand. As a consequence, soil phosphoruslevels are often well above the critical level. By identifying soils and conditions where continuous cereal systems perform best and where inputs can be most effectively targeted, there is an opportunity to reduce input costs and increase profitability. This trial used PA methods to identify soil types for targeted soil sampling to achieve a greater understanding of soil phosphorus levels in different soil zones. Yield mapping was then used to identify if and where fertiliser applied to the crop impacted grain yield.
Lead research organisation |
Society of Precision Agriculture Australia |
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Host research organisation | N/A |
Trial funding source | GRDC SPA000010 |
Related program | N/A |
Acknowledgments |
Colin and Chris Hunt, Collaborating farmers, Mildura. Michael Moodie (Mallee Sustainable Farming) |
Other trial partners | Not specified |
Crop type | Cereal (Grain): Wheat |
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Treatment type(s) |
|
Trial type | Precision agriculture |
Trial design | Not applicable |
Sow rate or Target density | 30 kg/ha |
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Sow date | 20 May 2010 20 May 2010 |
Harvest date | Unknown |
Plot size | Not specified |
Plot replication | Not specified |
Fertiliser |
DAP |
Other trial notes |
The response to additional fertiliser on the sandy loam soil zone was approximately 0.2 t/ha per 30kg/ha of DAP. At a grain price of $210/t and a DAP price of $750/t, applying the fertiliser on the sandy loam soil type increased profit by approximately $20/ha in the 30 kg/ha treatment and $40/ha in the 60 kg/ha treatment. Phosphorus supplied through DAP cost approximately $4 per kilogram of P and 5.4 kg/ha of P are supplied for each 30 kg/ha of DAP applied. However, if the yield response was attributed to the nitrogen component of DAP, then the cost of the nutrient would be $7.50 per kilogram of nitrogen supplied through the DAP (3 kg/ha N supplied with 30 kg/ha of DAP). This nutrient can be supplied at the much lower cost of $1.40 per kilogram of nitrogen by using urea at a cost of $650/t. Therefore further work is required in this paddock to identify if the phosphorus, nitrogen or a combination of the two nutrients is providing the yield response. |
# |
Treatment 1
|
Soil nitrate (mg/kg) | Colwell phosphorus (mg/kg) | pH CaCl2 (pH) | Colwell potassium 0-10cm (mg/kg) | Soil ammonium (mg/kg) | Plant available water (mm) | Sulphur (mg/kg) | Electrical conductivity (dS/m) |
---|---|---|---|---|---|---|---|---|---|
1 | █ Dune | 12 | 23 | 7.9 | 323 | 2 | 41 | 4.42 | 0.074 |
2 | █ Swale | 25 | 43 | 8.1 | 634 | 1 | 36 | 7.02 | 0.32 |
SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.