Growers across an estimated area of 2.5 million hectares are missing out on increased yields of 0.5-1.5 tonnes per hectare, due to the interaction between sodicity and transient salinity, often associated with high subsoil alkalinity and poor soil structure. DPIRD research suggests the estimated impact of sodicity and transient salinity on lost crop production is at least $130 million per year.
This $4.8 million project, with co-investment from Department of Primary Industries and Regional Development and the Grains Research and Development Corporation, will explore management options and treatments to increase water availability to the root zone.
It will involve a series of field and glasshouse experiments using wheat and barley indicator crops within the Geraldton, Albany, East Kwinana and Esperance port zones to evaluate a combination of mitigation and amelioration strategies to determine the most profitable benefits.
The project will also assess novel options including:
· Water harvesting though furrow formation and the use of strategically placed water repellent compounds on the ridges including spray on polymers.
· Reducing dispersion through in-furrow or broadcast applications of gypsum.
· Improving root growth by soil loosening and the addition of soil amendments (compost, straw, gypsum).
· Reducing soil water evaporation through the addition of mineral mulches.
While each component will be assessed individually, it is expected that a combination of mitigation and amelioration approaches may be required to provide the largest and most profitable benefits.
Data generated from the trials will be incorporated with crop simulation models to generate preliminary long-term data sets and determine the profitability and reliability of these treatments.