BACKGROUND

The impact of land management practices on deep drainage and dryland salinity

One way in which farmers gather information about land management strategies is to look over the fence and see what other people are doing.
By talking and sharing information with other farmers and land managers, farmers have more information available to develop land management strategies that will work for them.

Across the Fenceline is a joint project between CSIRO Land and Water, the Harden Murrumburrah Landcare Group and the Grains Research & Development Corporation, that aims to address the problem of managing dryland salinity through a combination of monitoring and community education.

In southern NSW, winter/spring rainfall that is not used for evapotranspiration by current land management practices or lost across the landscape as runoff drains through the soil profile. This deep drainage through subsurface layers collects salt and contributes to dryland salinity, river and water quality decline.

Real-life solutions

Real farms don’t leak in the same ways that research plots do. Across the Fencelines monitors deep drainage on real farms, using a CSIRO-developed tool called a tube tensiometer. The tube tensiometer can objectively measure levels of deep drainage under different land management practices, and communicate the actual level signals to farmers and advisors.

The chosen sites are visited frequently and have become a focal point for farmers and advisors to meet with researchers to discuss possible solutions to the rising water tables using available water and increasing incidents of identified salinity across the region.

The project demonstrates the drainage differences between different land management systems. The tube tensiometer meters are deployed in an annual cropping system, an improved perennial pasture system and a best practice phase farming system, on a range of representative soil types.

A major outcome will be to provide reliable data to identify the most effective strategies to overcome the problem of high salinity levels in the Jugiong Creek catchment. This catchment has been listed in the Salinity Audit of NSW as having severe salinity problems and addressing this area could help achieve the interim end-of-valley salinity target.