18 



or smaller admixture of the "York guni" tree (E. loxophleba, 

 Bentham) to the wattle or jam tree. Such land makes splendid 

 corn land, and is more generally found on the slopes of the 

 undulating country which constitutes its home. On the flats the 

 soil is often of a lighter character, and there the wattle or the 

 jam bushes predominate. On the river banks and in patches over 

 the country, a lighter loam still is found and is generally over- 

 grown by the above-named trees, in company with the banksias, of 

 which there exists several varieties, and at times with the "sheaoaks" 

 (Casuarinas). 



Considered on the whole, the chocolate loam or wattle and jam 

 or York gum land is one of the best balanced in the elements of plant 

 food in the South- West districts of the State, and were it not for, 

 in some seasons, a scanty rainfall, would carry enormous crops of 

 grain, hay, or fruit. Fields not long cleared and cultivated yield, 

 in average seasons, 16 26 bushels of wheat to the acre, and 30 

 40 cwts. of hay. Richer patches of land occur in this country, 

 where the "manna gum" tree grows (Acacia microbotrya) cele- 

 brated for its enormous yield of gum). Those patches are 

 generally of volcanic origin and of great fertility; blackboys of 

 very large size also grow on such soil. At places over that country 

 salt patches are not uncommon, and generally follow up the 

 clearing of the land. Their occurrence is more noticeable in what 

 would have been the most fertile land in the field, in hollows, or at 

 the base of sloping ground, where these salts accumulate, owing to 

 the leaching process after heavy rainfalls, as well as by the general 

 seepage of the more easily soluble alkali salts, notably those of 

 sodium. 



SALT PATCHES. 



Two sorts of salt patches occur in the drier regions of the State : 

 the white patches caused by formation of crust or efflorescences on 

 the surface of the soil of salts, which present the appearance of 

 hoar frost on the ground. These salts mostly consist of common 

 salt (chloride of sodium), with chlorides and" sulphates of calcium 

 and magnesium. Unless present in large quantities, these salts are 

 comparatively harmless. 



The second, the black salt patches, are more injurious to vegeta- 

 tion, and in addition to common salt contains G-lauber's salt 

 (sulphate of soda), and with it a varying amount of a substance most 

 destructive to vegetable tissues, viz. : carbonate of soda or sal. 

 soda. The presence of that salt is always indicated by the colour of 

 the soil in the black salt patches. The latter salt has, on the 

 tissues of plants, a corrosive action ; it dissolves the humus con- 

 tained in the soil, and thus gives it the characteristic black colour 

 often noticeable in such patches. The presence of this chemical 

 salt in the soils is absolutely detrimental to the growth of roots of 

 the plant, whereas the salts found in the white patches are only 

 injurious when their accumulation becomes excessive, especially at 

 the surface. 



