Assessing the change in soil quality as a result of drainage intervention and finding ways of mitigating the adverse affects

This project aims to explore impacts on soil properties from engineering solutions (positive or negative) designed to drain salt affected and waterlogged land for conventional agricultural use. However, given the diverse nature of soils subject to salinity and waterlogging in Western Australia, the expected responses in soil quality to drainage will vary. Hence, it is important to identify where drainage will be effective in reclaiming soils to productive agricultural use. Soil types may also variably affect quality of drainage water downstream. However, little is known about the factors affecting discharge of nutrients (N & P), salts, sediments and other agricultural chemicals (heavy metals - cadmium and pesticides - atrazine) in soils with drainage intervention. Hence there is a need to asses the impact that drainage intervention may have on the mobility, availability and eventually on leakage of agricultural inputs under different soil types. Hence, data sets will be collected from sites with differing levels and types of drainage intervention that will enable the development of risk profiles for these new practices.

Objectives

1. Investigate changes in soil chemical, physical and biological properties in salt affected areas and the reversibility of these changes once water table levels are dropped. Relationship of these changes to quality of drainage discharge water will also be determined;
2. Using AgWA's land resources databases, determine the most likely soils associated with different types of drainage and categorise the reversibility of salinity when drainage is installed in different soils and estimate by mapping the likely distribution of the soils and impacts;
3. using soils amendment materials (ripping, gypsum, lime, organic matter), evaluate the performance of different rates of these materials in overcoming adverse affects of soil chemical, physical and biological properties and site productivity after drainage.

Project Team

The project will be managed by Murdoch University in collaboration with Chemistry Centre Western Australia (CCWA), Dept of Agriculture Western Australia and Centre of Excellence in Natural Resource Management, UWA Albany (CENRM).

Murdoch University

• Dr Richard Bell, Associate Professor in Land Management, School of Environmental Science
• Dr Halina Kobryn, Lecturer in Remote Sensing and GIS, School of Environmental Science
• Mr Carlos Raphael, Research Officer, School of Environmental Science

CCWA

• Dr Surender Mann, Natural Resources Group
• Dr Dave Allen, Natural Resources Group

Dept of Agriculture, Western Australia

• Noel Schoknecht
• Dr M. Hamza
• Mr Justin Hardy

Centre of Excellence in Natural Resource Management, Albany

• Dr Craig Russell, Research Fellow

For further information, please contact Assoc Prof Richard Bell.