198 



rainfall, the depth and nature of the soil and of the sub- 

 soil, the particular variety and age of the trees, the climate, the 

 quantity as well as the quality of the water at command, and the 

 means and facilities of bringing water on to the land all require 

 consideration. 



Speaking generally, a rainfall of 20 inches on deep loam fairly 

 rich in vegetable matter, and possessing good absorbing and reten- 

 tive power, may prove sufficient for an orchard planted with 

 deciduous trees, provided that amount of moisture is well tended, 

 and by good cultivation prevented from escaping by evaporation. 



Under similar circumstances, 25 inches may not be too much 

 for evergreens, such as citrus trees, which require more water. 



On deep, dry, sandy, or limestone formation, however, or on 

 thin soil overlying solid rock, the plants would very likely show 

 signs of distress even with a greater amount of rainfall. 



Crops possess different degrees of thirst, their exigencies in 

 this respect running approximately in the following order : 



i . Meadows and artificial pastures. 



2. Maize and sorghum, for green crop. 



3. Lucerne. 



4. Rape and root crops. 



5. Tares, oats, and peas. 



6. Fruit trees. 



7. Wheat and rye. 



8. Grape vines. 



In the course of an ordinary season, the climate and the soil of 

 thejbulk of the South- Western division of Western Australia has 

 been proved to possess sufficient rainfall and sufficient absorbing 

 and retentive power to supply all requirements of the last four of 

 these groups of cultivated crops. After a dry season, however, 

 even these more pronounced drought-resistant crops will suffer 

 more or less, and fail to yield a full crop, except at especially 

 favoured spots, or unless artificially watered in the proper season. 



The age of trees, too, and the distance apart they are planted, 

 influence to a very marked degree their moisture requirements. 

 Evidence is not lacking of a number of orchards established in 

 various parts of the country which, when young, produced crops of 

 first-class fruit, and which as the trees became older and the space 

 between the trees decreases with their growth, bear a class of fruit 

 inferior in size, appearance, and flavour. In such instances water- 

 ing often proves very profitable. It is simply reduced to a question 

 of ways and means. 



METHODS OF IRRIGATION 



differ with the nature of the crops grown. As a rule, the 

 method of flooding land is practised in the case of pastures, 



