Spading increases yields on Mallee sands
Authors: Melissa Fraser1, Nigel Wilhelm2, David Davenport1
Research Team: Peter Telfer2, Brett Masters1, Amanda Schapel1, Claire Dennerley1
1PIRSA Rural Solutions SA, 2South Australian Research Development Institute
Funded By: GRDC Sandy Soils CSP00203
Project Title: Increasing production on sandy soils in low and medium rainfall areas of the Southern Region
Peer Review: Therese McBeath
Key Words: spading, yield, sandy soils, sands
Key Messages
- Spading a sand at Karoonda has resulted in 2.47 t/ha (61%) more grain than the control over 4 crops (Fig. 1) at a cost of $80/ha.
- Only an extra 1.04 t/ha of grain (87% over the control) was achieved when 10 t/ha of lucerne was incorporated with the spader (Fig.1 Spading + organic matter (OM)) compared with spading alone.
- In 2014, 2015 and 2017, spading with OM had the biggest impact on performance.
- Crop responses after spading are thought to be the result of a reduction in soil bulk density, soil strength and the severity of water repellence.
- Changes in soil chemical, hydrological and biological characteristics as a result of spading and OM addition is the focus of 2018 soil measurements at the site.
- High bulk density and soil strength were also overcome in the deep nutrition treatment (liquid fertilisers, N62:P30:S19:Zn4:Mn6:Cu3, banded at 35 cm) and resulted in higher yielding crops (Fig. 1).
- The response to deep ripping with and without extra OM or fertilisers, in contrast to using a spader, is the focus of future research to be conducted by PIRSA on a sandy soil at Murlong on the Eyre Peninsula.
