Measure your recharge

Paul Hutchinson installs a drainage meter.

Growers will soon be able to keep easy track of how much water escapes the cropping level to the watertable, thanks to a new drainage meter developed by CSIRO Land and Water scientist Paul Hutchinson.

The drainage meter is simply a PVC tube filled with finely ground silica powder which soaks up water from the soil as if it was blotting paper. The amount of deep drainage is then calculated from the depth of the water in the silica powder in the tube.

According to Dr Hutchinson, the new meter will give growers the window they need to watch the effect of their crop management and rotations on recharge. The meter was developed with the support of growers and the Federal Government through the GRDC.

"For the first time, growers will be able to get this information directly, on their own properties, without an expensive monitoring program run by scientists," says Dr Hutchinson.

Many growers living with salinity and waterlogging will be accustomed to monitoring piezometers and test wells. For these growers the technology will be reasonably familiar, although some form of electronic datalogging is still necessary.

The drainage meter can be buried below the plough layer, allowing growers and field scientists alike to measure soil-water content throughout a growing season without disturbing the crop or the soil in the process. This gives the drainage meter the edge over more complex devices without losing any of their accuracy.

Dr Hutchinson expects that scientists and growers will find the new drainage meter to be of great help in improving farming systems to better manage their soil water, deep drainage and recharge.

Program 3.4.4

Contact: Dr Paul Hutchinson 02 6960 1558