Now that harvest is complete and most have been away for holidays before school goes back, it is time to collect yield map data that may be still stored on data cards.  It is better to collect the data early before seeding and during a relative quiet period to ensure it isn’t lost or saved over before next harvest. Yield maps are a valuable resource for comparing yield variation across paddocks that may not have been picked up at harvest or alternatively have been forgotten. 

Yield maps can be used to obviously view the yield for a particular paddock or farm. They can also be used to estimate nutrient removal and therefore used to create a nutrient replacement program. This is becoming particularly important with the increasing costs of fertiliser. Saving yield maps for viewing sometime later, means you don’t have to reply on remembering where the yield decline or increased was and the maps can be compared over different seasons to see if there is a common trend to paddock variation.

With most new machinery, yield monitors come standard, so to collect the yield data, the addition of a GPS signal and data card are all that are needed.  Many farms already have a GPS signal for guidance, otherwise the family GPS used for fishing or hiking can be connected to the yield monitor to provide a signal.  Purchase a data card to store the collected yield information and your yield mapping, it’s that simple. 

Computer software is also being supplied with most new harvesters and many of these will provide farmers with a map good enough to locate any major yield variations.  If more accurate maps are required, there are additional steps needed to smooth maps and remove any outlines or anomalies that may have occurred.  A recent article by Sam Trengove in the Southern Precision Agriculutre Association newsletter outlines this process in detail, so refer to this for reference (www.spaa.com.au).

For those farmers that aren’t yield mapping, I urge you to investigate what equipment you have because if your harvester contains a yield monitor, you’re only a few small steps and not a lot of money away from yield mapping.  Who knows, if in the future you may want to sell your farm this yield data could be a value resource for showing the potential yield of your property to potential buyers.  Also, as suggested earlier, by locating lower or higher yielding areas within paddocks, fertilisers can be varied to better match paddock variation, and save money.

Rural Solutions SA are currently working with farmers and conducting trials in the Upper South East and Murray Mallee as part of a NLP and DWLBC funded project to test the benefits of variable rate technology, with 2007 results soon available to farmers.  If you want any information regarding these trials or want to be involved in focus groups contact; Craig Bell or Peter Treloar of Rural Solutions SA.

AUTHOR: Craig Bell, Sustainable Agricultural Systems Consultant, Rural Solutions SA
CONTACT: Craig Bell, Rural Solutions SA Murray Bridge Office, Telephone: 08 8535 6421, Mobile: 0427 002 534, Email:bell.craig@saugov.sa.gov.au