Soil probes may hold data key

Corrina RidgwayCountryman

Soil moisture probes, more at home in horticulture and vineyards to determine amounts of plant available moisture for irrigated crops, are set to provide croppers data for the future.

Both private landholders and grower groups are starting to recognise the value of the probes and the Northern Mallee Farm Improvement Group (NMFIG), headed by Laurie Starcevich, has been one of the first organisations to invest, installing a unit in May.

“We have funding in partnership with Grains Resources Development Council (GRDC) and the Department of Agriculture, ” Mr Starcevich said.

“Part of our funding we’ve used to purchase the probe. They are about $5,000 each.”

The one-metre probe, 60m inside a paddock’s boundary, starts 200mm under soil surface and measures every 100mm along its length, collecting data on soil moisture, temperature and salinity.

The information gathered is relayed to a telemetry unit, at edge of the paddock along with a rain gauge. Every 15 minutes the data is sent via mobile phone network to a website accessible by probe owners.

Further support from Ravensdown gave the group an opportunity to carry out soil tests over 405ha to determine the best average soil type before the probe was implemented.

Core tests through the soil profile were done before the final site was chosen.

Installed by Precision Agronomics, units are starting to emerge across the State. The largest concentration is in the Esperance region.

Although initial costs including soil tests may seem expensive, the probes are essentially a low-cost item.

Associated costs to run the website are about $200 year and data is uploaded with a $5-a-month SIM card. The units also run on their own solar panel.

The NMFIG is already excited about data collected and the implications it may have.

“It’s only been in two months. Already we have seen that there was actually 98mm of plant available moisture in soil through the longest period of dry that most can remember, ” Mr Starcevich said.

Precision Agronomics consultant Quenten Knight believes farmers will appreciate the fast access to better information.

“The information is in simple, easy to read graph form. It’s at their fingertips, ” he said.

However the greatest value will be for future generations.

“Hopefully it will show how different crops respond to a season, ” Mr Starcevich said.

“For us, information on available moisture after the summer rains will be interesting ...especially after five or more years of data.”

The data will directly assist growers looking at better efficiency.

Mr Knight said that, long term, the data would be applied to planning and input decisions.

“Growers will make better in crop decisions, for example, how much Nitrogen is needed, due to subsoil moisture, ” he said.

More informed decisions on grain marketing are also likely, as agronomists are able to analyse the data and consult back to the farmers.

Possibilities for data gathered from different probes to be correlated to create a complete subsoil moisture overview could reap other rewards — coupled with rainfall and soil type data this could be applied to varietal breeding.

“They can be used as a full weather station, ” Mr Knight said.

“One in Geraldton is taking humidity, solar radiation and wind direction readings too.”

A smaller extension to monitor the top 200mm of a soil profile can also be fitted to existing units, to gain a complete profile picture.

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