Estimating Plant Available Soil Water (SWApp)

“New tools to measure and monitor soil water” (GRDC project USQ 00014)

SoilWaterApp V3 was released to the App Stores on 10th November 2016.

SWApp provides farmers and advisers with a ready estimate of plant available water (PAW) in the soil during fallow and crop phases. SWApp estimates soil water (PAW) using a proven water balance model  and inputs from:

  • weather data from a nearby Bureau of Meteorology (BoM) sourced from the Silo (;
  • rainfall data from:
    • a local gauge (manual entry);
    • a Bluetooth enabled rain gauge (20m range);
    • Netatmo weather stations with a rain gauge; and
    • A "Data Cloud" which accesses a range of commercial instruments (under development).
  • a soil description best suited to your paddock; and
  • soil and crop cover conditions for each paddock.

SWApp considered all components of the water cycle on a daily basis and uses long-term climate data to provide a forward-looking estimate of likely outcomes for the specified soil, location and fallow/crop conditions. 


SWApp was developed for the Grain Research and Development Corporation by the University of Southern Queensland.

Additional funding from the Australian Government's National Landcare Program has allowed further development of a connection between a National Soil and Landscape Grid (soil slections) and more sources of local daily rainfall.

The project team includes: 

Dr. David Freebairn and Dr Brett Robinson (project managers), 

Dr. David McClymont of DHM Environmental Software Engineering (software engineering), 

Mr. Victor Skowronski (Electrical Engineer)

Erik Schmidt (project administrator),