204 



Journal of Agriculture, Victorid. [lo April, 1912. 



soil consequent on fallowing, and partly clue to the continual practice of 

 stubble burning. 



In later articles it will be necessary to consider the probable ultimate 

 effect of such losses and the possible methods of counteracting them. 



(7) Each of the essential ash constituents mentioned above, though 

 aggregating less than 5 per cent, of the dry-matter, are nevertheless abso- 

 lutely necessary for the life and full development of the plant, and it is 

 the most deficient of these constituents which determines wiiat the harvest 

 shall be. 



(8) The four constituents, lime, magnesia, iron, and sulphur are con- 

 tained in such small quantities in the w'heat plant and in such large quanti- 

 ties in the soil that the soil supply is ne\'er likely tO' be depleted in these 

 ingredients. 



Thus in most cases the problem of maintaining soil fertility, so far as 

 it is governed by purely chemical consideration, ceiitres round the adequacy 

 of the nitrogen, phosphoric acid, and potash content of the soil. 



Lime sometimes becomes of great importance in the maintenance of soil 

 fertility, but the necessity for lime in such cases invariably arises from a 

 faulty biological and physical condition of the soil. 



(9) All these mineral substances can enter plants only through the roots 

 and root hairs and in the form of a dilute mineral solution. 



We may now turn from the elementary composition of the wheat plant 

 to a consideration of its proximate constituents, and particularly with the 

 proximate composition of the kernel itself. 



The composition of the kernel may, perhaps, be best understood by 

 considering it in relation to the products obtained in the process of milling. 

 To gain some information on this point a sample of Federation wheat, 

 grown at the Parafield Wheat Station (S.A.) in 19 10, was milled in the 

 Departmental Flour Mill, and the original wheat, together with the flour, 

 bran, and pollard was analyzed by the Chemist for Agriculture of this 

 Department (Mr. P. R. Scott). The following table gives the amount 

 of the proximate constituents — water, fat, carbo-hydrates, fibre, protein, and 

 ash in the bran, flour, pollard and wheat: — ■ 



TABLE in. 



I. Water. — It will be noted that this particular sample of Federation 

 contains about 11 per cent, of moisture, whilst lesser quantities of this 

 ingredient are found in the flour, bran, and pollard prepared from it. 



