14 Journal of the Department of Agriculture. 



or six bags. Tliis mems a decline in yield of nearly half. It also 

 mepns that for that particular crop the value of the irrigation works 

 lias depreciated 50 per cent., wliicli is surely an alarming* develop- 

 ment. 



There may he those who would put down tlie decline to the soil 

 having heconip depleted of one or more plant foods. The possibility 

 of iliis having happened in so short a time is very remote indeed, 

 especially Av'tli respect to the type of land usually irrigated. It is 

 much more likely that the use of water has introduced what may be 

 termed " adverse " or " limiting " factors, the action of which results 

 in full benefit not being derived from the water supply. 



Frequently the limiting factor is brak and sometimes it is an 

 excess of water. 



Yields in the Presence of Brak. 



Now, although brak may prevent any yield whatever being 

 obtained, and even prevent the germination of seed, it must not be 

 thought that even if averag'e yields are obtained there is no })rak. As 

 a matter of fact a little brak in the soil is a good thing, provided it is 

 of the right kind. The right kind of brak assists in maintaining" a 

 good physical condition of the soil without which the latter cannot 

 give its maximum yields. Brak also exerts a beneficial influence in 

 rendering the i)hint nutrients of the soil available. But brak of 

 whatever kind, if present in excess, leads to diminished yields, 

 the decrement being proportionate to the excess of brak. The 

 greatest losses are no doubt those which are not noticed ; they are 

 akin to, say, a return of 4 per cent, on money invested, when by 

 better management 5 to T per cent, would be obtained. Losses from 

 brak only follow when water is used wasteful ly. By wastefully is 

 meant in either too little or in too great quantity. Included in the 

 latter instances are lands whose condition is such that they, should 

 not be irrigated at all. 



Irrigation Demands Knowledge and Skill. 



The onlooker is apt to assume that it is a much simpler matter to 

 grow crops under permanent irrigation than under a good rainfall; 

 but there is not the least doubt that the production of cro])s under 

 irrigation demands much more skill and knowledge than the produc- 

 tion of crops under rainfall only. One has only to consider why so 

 many millions of money have been lost in the shape of lauds ruined 

 by irrigation to appreciate the truth of my assertion. 



The Meaning to be Assigned to the word " Brak." 



Before i)roceeding further it is necessary that we should be agreed 

 upon the meaning to be assigned to the term "brak." The word is 

 closely related to the English word "brackish," Avhich means salty. 

 If " brak " be used in this sense, then it is only when a water or soil 

 is salty to the taste that it can be said to be brak. There are farmer? 

 who hold this view, especially in the north-west, where a fresh water 

 is one that tastes neither salty nor bitter as distinct from one that 

 does. 



Such re})uted fresh water may, however, be quite unsuited for 



