High-resolution information delivers the goods
2cm GPS, 5cm topography and 1m satellite imagery drive better on-farm decisions and management, writes Don Yule.
The Third Australian controlled Traffic Farming conference at Gatton in Queensland, in July 2005, brought together 104 leading growers from across Australia and across the grains, cane, cotton and vegetable industries. The conference reinforced two messages:
Grower presentations at the conference stressed that 10 years" experience was enough to prove the applications, opportunities and resilience of controlled traffic for future farming systems.
The mistakes have been made, the lessons learnt. It is now possible to change to CTF with confidence, and in the most cost-effective and timely ways for your farm business. "Just do it - the basics have been identified" became a slogan of the conference.
Also, experience has shown the costs of making wrong decisions during the development process. Many of these decisions seemed right at the time but we can now make much better decisions. "Don"t muck about, do it right" - a second conference slogan.
The CTF "basics" include strategic planning, farm design, paddock layout; identical wheel tracks and matched equipment widths (controlled traffic for all machines); zero till and best agronomy. We now need to develop new agronomy for our new, non-compacted CTF cropping soils.
Currently available IRA technologies include yield monitors, satellite imagery, topographical surveys, aerial imagery, soil tests for nutrition, moisture and disease, electromagnetic (EM) surveys and gammaradiometric (GR) surveys. These technologies are based on global positioning systems (GPs) and provide spatially accurate, high-intensity data (hundreds to tens of thousands of data points per hectare). These data can then be analysed in geographic information systems (GIS) platforms.
The aims of our project are to determine which IRA technologies are valuable to growers, how they could be delivered to growers and how growers could use them.
IRA technologies fit very well in CTF systems. GPs-based systems are becoming commonplace. But are the benefits of auto-steer optimised if you have different wheel tracks across machines or if you go round and round?
Compaction from random traffic causes enormous loss of production in the grains industry. "If you can"t see wheel track effects in your paddock, probably your whole paddock is compacted." All our experience with mechanised agriculture is based on degraded, compacted soils and the change to CTF is showing how large those losses are.
Operations on dry soils cause less compaction but the "we always have dry harvests" story does not make sense. One wheeling is enough, and one wheeling of damp soil will destroy the repair from years of CTF.
Growers at Gatton reported responses in soil health (compaction repair and increased biological activity) occurred after one season of CTF, across a range of soil types. Papers by growers and researchers all pointed towards valuable outcomes from combining CTF and IRA including:
GPs and auto-steer is at present sold mainly for the benefits of reduced driver fatigue, less overlap and night operations, but the high level of accuracy in a welldesigned 2cm GPs CTF system can also drive higher productivity.
Higher yield potentials follow from reducing soil degradation and improving timeliness and management. And it is whole-farm performance that counts, not just the best paddock.
The conference discussed CTF-related standards. Three-metre wheel tracks with up to 500mm tyres or tracks and 9m equipment modules work extremely well in grains systems, because it suits the whole system. The 12m module may develop over the next few years.
Cane, cotton, vegetable and raised-bed growers baulk at 3m/9m systems because 2m/8m or 2m/6m systems have been the norm. The increasing use of grain crops as part of rotations in these industries creates a challenge, when grain harvesters are typically 3m wheel track. Systems based on the 2m wheel track are needed.
When all components in the system are considered, effective solutions generally become obvious.
Figure 1: Adding layers of spatial information in a gis suggests causes of paddock variability and management responses. Here, the 20cm topographic overlay on an aerial photo (which shows soil types) assists layout design for raised beds.
Figure 2: Higher resolution means better information, means better understanding, means better management decisions. From left: 25m pixel (16 values/ha), 10m pixel (100 values/ ha) and 1m pixel (10,000 values/ha).
GRDC Precision Agriculture Initiative (SIP09)
GRDC Research Code: CTF00002
For more information: Dr Don Yule, CTF Solutions, 07 3871 0359 or 0427 113 127, email@example.com.
Conference papers can be found at www.ctfsolutions.com.au
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