NOTES ON OSTEO-MALACIA (BONE-CHEWING). 9 



The absence of vegetable matter hinders the transformation of the lime 

 silicates and zeolites into carbonate, in which form the lime is most beneficial. 

 The hardness of the surface soil prevents water and air from reaching- the 

 subsoil, hence that animal life particularly earth-worms which should 

 exist in the soil to maintain its fertility, is absent. The lime is therefore 

 not brought up to the surface by these animal agencies. As a result, only 

 the. hardiest and coarsest grasses will grow. This probably accounts for the 

 rapid spread of Bergalia grass in the South Coast districts in recent years. 



It appears, therefore, that this land suffers from a kind of exhaustion 

 brought on by clearing and overstocking, without any effort to maintain the 

 condition of the soil. 



To give each paddock in turn a complete rest for a year or two would 

 probably be beneficial, inasmuch as it would restore some vegetable matter 

 to the surface soil. It would be still better to break up the surface prior 

 to giving the land a rest. It is clear from the analyses that the lime is 

 never completely exhausted, but it must be in a form little suited for the 

 needs of the grass. 



The addition of lime to the soil has, according to Inspector Eurness, 

 proved of benefit both to the grass and to the cattle wherever experimentally 

 tried; but in some cases, as for instance on the Bergalia andesite, it is like 

 " carrying coals to Newcastle," the lime being there, if only the land- 

 owner will give it a chance to become available. 



In the writer's opinion, to rest and aerate the paddocks will, in certain 

 cases, as at Bergalia, do far more good than to spread lime on the surface, 

 and to give licks to the cattle. This is the way to get back the good grasses 

 and heavyweight cattle of former years, now fast disappearing. Each 

 paddock in its turn should be rested and broken up, to restore its fertility. 

 Overstocking year after year should be avoided, since the eating off of the 

 grass prevents that return of vegetable matter (humus) to the soil which 

 is desirable, and exposes the soil to the extreme burning rays of the 

 sun and the patter of the rain. 



Tables IA and IB give the analyses of soils from affected and unaffected 

 areas respectively in the Bega district, which were sent by Stock-Inspector 

 C. O. Eurness, through the Stock Branch, for investigation. The difference 

 in lime and phosphoric acid is very striking. The lime content of the osteo- 

 malacia soils is invariably less than '275 per cent., and that of the 

 " unaffected " soils greater than '300 per cent. The phosphoric acid of the 

 affected areas is always less than '125 per cent., and that of the free areas 

 greater than *125, except in one instance. The volatile matter of the 

 unaffected areas is double that of the affected. The nitrogen and humus 

 percentages are also much lower in the osteo-malacia localities than in 

 places where the disease does not occur. Magnesia varies pretty constantly 

 with the lime. Other oxides of metals exhibit the same striking variation. 



The subsoil of the affected areas is typically a hard, gravelly clay, which is 

 very low in oxides of lime, magnesia, and iron; it consists chiefly of very 

 fine quartz and felspar, very little of which is sufficiently decomposed to be 

 acid-soluble. 



1 99119 B 



