False Salinity Information Is Costly To Farmers
October 29, 1999 the Rural news
Information being given to Southern Tableland farmers about salinity is inaccurate and has cost some farmers dearly, according to former Yass soil conservationist Rex Wagner.
Mr Wagner said information released on salinity development across the Tablelands by departments is based on guesstimates and was leading many farmers in the wrong direction.
Using sequences of aerial photographs covering land between Goulburn, Crookwell, Yass, Boorowa and Braidwood dating hack to 1940, Mr Wagner claims the worst salinity occurred before 1973.
His findings, part of a Masters thesis with Australian National University. Canberra, contradict information being given to Southern Tableland landholders today.
The information being given to farmers, advising them of salinity - the sleeping giant, evolved from a 1982 over-the-phone farmer survey by soil conservation district officers which, according to Mr Wagner, underestimated the problem.
He believes the problem of salinity was as bad then as it is today, "but the extent of problem is now being recognised" Mr Wagner said.
"A basic phone survey estimated the area with salinity problems. Then (the survey found) 4000 hectares in the area was affected by salinity," Mr Wagner said. In 1992 an estimate across the same area was made using aerial photos. It announced 14.000 hectares of dryland salinity across the Southern Tablelands.
Mr Wagner said rather than having facts "from the field" to back the increased figure, estimates and extensions of earlier data are the backbone of the "growth theory".
"All that has happened is they have extended the data which doesn't match the field situation," Mr Wagner said. "A salinity increase of 250 per cent has been concluded from the 1992 research, but not allowing for different survey techniques". Mr Wagner's aerial photographs show the problem isn't recent, the phone survey overlooked the problem in some areas.
Mr Wagner also said he believed the information being released about the relationship between dryland salinity and a rising deep regional groundwater system was inaccurate. He believes salinity is a problem specific to areas, not total regions.
"It's is a localised spread which has developed episodically, this relates to a number of factors," Mr Wagner said. "The effect of ground water is associated with landscape features and soil type."
Seasonal changes also have an impact. "It (salinity) seems to have waxed and waned with the seasons over the years, the worst was in the 1950s and 1960s," Mr Wagner said. "A run of wet years followed by dry years bring outbreaks."
Sustainable farming systems are Mr Wagner's tool for reducing and treating salinity. "Farmers need to make more efficient use of moisture rather than maximising its use, they need to make productive use of it." Mr Wagner said.
"Measures involved in the control of salinity complement the controlling of other systems, there needs to be overall improvement - not specific.
"Pasture improvement is one very good way to improve, develop and sustain productive systems while counteracting salinity - the aerial photographs show this," Mr Wagner said.
These methods at local levels were effective for some farmers, he said. "Some dedicated farmers who attacked the problem at a local property level have been successful, while others, just as dedicated, have not had as much success."