The document discusses the implementation and economic evaluation of variable rate technology (VRT) for nutrient management in farming, particularly in northern mallee regions. It emphasizes the importance of spatial management, data calibration, and ongoing evaluation to improve input allocation and crop yields. Key points include addressing nutrient deficiencies, using technological advancements for data transfer, and learning from past experiences to refine VRT applications.

1. 1
Variable Rate Technology
Show me where the numbers add up.
A Northern Mallee Prospective
By Alistair Murdoch
Farmer

2. 2
Limited Root Access too Inter- Row Nutrients

3. 3
Introduction
• What we were looking to control with VRT
• How we developed a stable layer.
• Ongoing evaluation of our spatial
management.
• Economics: Our experience

4. 4
Better Allocation of Input $
• A run of poor seasons in the early to mid
2000’s had us questioning our fertiliser
spend.
• Dune – Swale land formation, so large soil
type variability.
• Need to allocate inputs to PAW
• Massive difference in nutrient removal
• Technology was pretty well there.

5. 5
Implementation
Developing a stable layer
• Elevation ?
• We had no yield maps?
• Ground truthing?
• EM 38?
• Gama?
• Limited NDVI?

6. 6
Calibration of Data Layers

7. 7

8. 8
Getting the Data to the Ground
• Having the data file in a readable
format for the task controller.
• Knowing your systems strengths and
weaknesses
• Technology today has data transfer as
a key priority

9. 9
Low NLarge Amounts of Sulphur and Nitrogen Deficiency

10. 10

11. 11
Ongoing Evaluation
• Test strips at planting– 0 and 2X rates
• N Rich stripes
• NDVI and Yield Data
• Ground truthing
• Stacked data.

12. 12

13. 13
EM 38
Yield Map 0 N stripe

14. 14

15. Sentinel 2 Image
15
0 P
Application

16. 16

17. 17
VRT use on-farm Today
• VR Fertiliser and Seed at Sowing
• VR Topdress of N and S with Kuhn
Spreader
• Split sowing of crop types with one
pass
• Some selective sprayer (Skelton Weed
and Couch Grass)

18. 18

19. 19
On Farm Economics
• Early N is Critical on Dunes: 1t/ha
advantage 2015
• P response is as much rotational as P
replacement.
• S Demand is closely linked to soil type.
• Not just macro nutrients that are worth
VR.

20. 20
Take home message
• Identify what you are looking to spatially
manage.
• Reach out to others to determine an
effective entry data layer to get you
started.
• Committing the time to evaluate your
spatial management approach.