SOIL EROSION

Otago Daily Times, Issue 22505, 25 February 1935, Page 7

SOIL EROSION

;a ; new south wales problem threat -10 productivity ' f FttbM OtJtt Own Correspondent. >' ' SYDNEY, February 14. \Soil erosion' is a danger to the productivity of the State that has only recently been realised by the Governmental authorities. Erosion is caused in a number of ways, but principally by hot, scalding winds on the western plains and by rain scouring of treedenuded hillsides. Scientists who have studied the problem have estimated that the wealth of the State has already been lowered by millions of pounds a year by soil erosion, which, if allowed to go unchecked, -would result in the impoverishment of huge areas of land. A New South Wales scientist last year studied the problem in the United States, where corrective measures have been in progress for some years. On his return, a committee was set. up, and the first review of its work has been issued. Thfi corrective measure for country where de-timbering has resulted in soil erosion is re-afforestation, and the committee has especially investigated the catchment areas of the three big irrigation dams in New South Wales—Burrinjuck, Hume and Wyangala. In the Burrinjuck catchment investigations have been made to determine types of land liable to erosion, and arrangements have been made with the Lands Department to prevent the clearing of timber on such land, while making it possible for tracts of country within the catchment not liable to serious erosion being cleared and settled. In the mountainous part of the Hume catchment area a total of 285 square miles has been dedicated as a catchment area, from which the present trees will hot be removed and on which more trees will be planted. A preliminary survey of country town water supply catchments has been made, and detailed investigations are being continued in those instances where erosion was evident. The lands adjoining the' foreshores of the Wyangala dam have been reviewed, and necessary action taken to permit of the leasing of such lands under conditions that will provide proper safeguards by the preservation of timber against the possibility of erosion.

With a view to obviating delay in the suitable disposal of areas within the catchments of water schemes controlled by the Water Conservation and Irrigation Commission, the committee has come to an arrangement with the Department of Lands in order that areas might be leased with safeguarding conditions for the preservation of timber on the steeper eroding country. A recommendation has been made to the responsible Ministers that the committer should be given powers to control ihv conditions aiming at the prevention of erosion of.lands suitable for disposal. Considerable destruction of highly productive lands has been. noted, more particularly in the wheat areas, which, in the opinion of the committee, could be controlled by appropriate methods of cultivation. An attempt is being made to develop a sense of the importance of adopting such methods of cultivation as will tend to reduce the menace to a minimum.

In the western areas large tracts of country are becoming wind swept and scalded through the removal of the surface soil, which has followed the destruction of the former timber, scrub and saltbush cover. With a view to determination of the rate of soil removed by wind, experimental plots have been laid down in the Euston district, and an attempt is being made to ascertain what methods of control jhotild be recommended. The banks of the coastal rivers of the State are particularly liable to erosion consequent on flood, wind and wave action, and in some rivers the continuing damage culls for urgent and definite action.