COPPER DEFICIENCY

Wairarapa Times-Age, 2 October 1939, Page 3

COPPER DEFICIENCY

FINDINGS IN AUSTRALIA.

IMPROVEMENT OF PASTURES.

In coastal districts of South- and Western Australia a disease closely resembling our so-called "bush sickness" affects the stock, and is known as “coast disease.” This has been discovered to be caused by a deficiency in the sand dune country chieflly affected, of cobalt and copper. The soils in areas where this disease occurs are, in addi - tion, unable to support superior perennial pastures or cereal crops.

The two grasses which do thrive on this deficient soil—brome grass and hare’s tail grass—are both harsh, early maturing, annual types, and apparently can thrive in the absence of copper and cobalt from the soil. The reason for the absence of other grasses and legumes common in most natural pastures is that such species are unable to thrive under,the particular soil conditions. The two resistant grasses, although able to grow normally and set seed, are unable to satisfy the min? eral requirements of grazing sheep. Investigations by members of the Animal Nutrition Laboratory of the Council of Scientific and Industrial Research, and the Waite Institute, working in collaboration, have proved that the cause of the pasture and crop failure is due to a deficiency of copper in the soil, and that an application of copper sulphate at the rate of from 171 b to 561 b per acre allows of apparently normal crops and pastures being produced.

It is extraordinary that copper is not, as. a rule, deficient in copper “deficient” soils, but is present in an insoluble form and unavailable to the plants. Only a minute amount is required by the plants, and it is said that oats, for instance, contain only about six parts of copper in 1,000,000 parts of the dry material, and other crops contain .a similarly small amount. It is possible tha't these minute amounts of copper enable the plant to take up necessary supplies of cobalt and perhaps iron, which affect the health of both the plants and the stock which graze upon them. It is possible that applications of copper to our “bush sick” country might have a Somewhat similar effect to that achieved in “coast disease” areas. The experiment of dressing cropping land, and perhaps pastures also, with copper sulphate in the bushsick areas would at least be worth while, as the cost of application would be negligible, and if results were satisfactory would be much less expensive than dressings of cobalt.