Linking nutrient movement to soil moisture

WHY THIS PROJECT WAS NEEDED

Having access to local weather data and up-to-date soil moisture information helps farmers make operational decisions, including around informed fertiliser applications.

Through a partnership with the Murray and Riverina Local Land Services (LLS), Riverine Plains installed seven on-farm weather stations across southern NSW during 2016.

These weather stations helped address the shortage of local real-time weather information. To obtain greater value from the weather station sites, a series of benchmark soil samples were taken from each site during May and August 2017 and January 2018. These samples, in conjunction with soil pit workshops held at selected sites, were used to better understand the soil profiles and properties across the region. The workshops and data helped farmers better understand how soil properties such as soil pH and carbon (C) change with time.

Project focus

Soil samples were collected at three depths (0–10, 0–30, and 30–60cm). These depth increments were chosen to reflect the different analyses at different depths (i.e. phosphorus is generally measured in the 0–10cm increment, while other analyses are generally carried out at the 0–30cm increment). The 30–60cm depth was sampled to capture nutrient movement to depth (i.e.nitrogen, sulphur).

Project outcomes

Key messages from the project were that:

• There was a high variance in soil chemistry parameters across the seven monitor sites
• Results showed the timing of sampling had some influence on the results obtained
• Consistency in sampling method and timing will improve the quality of results obtained

Full results were published in Research for the Riverine Plains, 2018, available at RPI Benchmark soil sampling of weather station sites across NSW.