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Soilmaster Copyright 1996 -Reme Soilmaster(TM)
METHODS OF MEASURING SALINITY - 2:
What methods do we have of checking salinity ?
Probably the most useful aid is our eyes to observe areas that have become bare or have salt crusts. We could "taste" the soil for a salty taste (if we are game) or have the soil tested for salt levels by a competent and experienced analyst or even a combination of all these things.
A new method does exist for measuring the relative amount of salt in the soil, but unfortunately it is not yet available for wide use in the area as it is still being researched.
C.S.I.R.O Division of Water Research has broadly developed this method, (using a hand operated meter) particularly in Southern N.S.W and Victoria, through the work of Dr. Baden Williams in Canberra. I was fortunate to work with Baden in the local area, where we have some problems. We found that we could measure the salt and then determine the effect on the land and methods to treat the problem.
The method involves a meter, which measures the relative amounts of salt in the soil. The meter sends ands receives signals to the earths surface and shows the relative amounts of salt in the soil. It can show hot spots of salinity and zones which have low salt levels.
And, what use is this ?
In irrigation areas, it can show the best area to drill where saline water occurs, or the presence of a zone where a sandy area is. These sandy areas, for example, are important in removal of water from the soil and can relieve potential salting of our valuable irrigation lands.
In the tablelands such a meter has been used to map farm land for salinity levels and could be used to predict likely areas where salinity would occur. Currently a mobile meter is being assessed by C.S.I.R.O for its usefulness in broad scale salt mapping near Tamworth.
It certainly appears that the meter is useful in broad area mapping. The use we can make of this, is to prepare a map of a farm where there may already be problems of salting and then determine the best place to start fixing the problem. Thiswould then lead to a long term solution to our dryland salt problem that affects some areas of Southern N.S.W
Next time we will talk about methods you can use to treat salt patches,
the best species of grasses and trees to use, some useful methods and some
traps in doing this type of treatment work.