TREES AND SHRUBS 315 



The methods of planting and maintaining trees are 

 not essentially different in irrigated and humid districts. 

 Irrigation is the one chief difference, and irrigation is not 

 the least important in producing and maintaining orchards 

 that justify the great expenditure of means that must 

 be made upon them. In orchards, moreover, the greatest 

 irrigation science has been applied, and in them the 

 highest duty of water has been obtained. 



Orchards lend themselves well to thorough cultiva- 

 tion, which may be one reason for the high duty of water 

 in fruit-farming. It is of extreme importance that cultiva- 

 tion be practised as thoroughly as possible in orchards. 

 The soil must be stirred immediately after each irriga- 

 tion, and several times between successive irrigations. 

 Both in spring, fall and early growing season should the 

 cultivator be at work in the orchard if the farmer expects 

 the greatest profit. 



189. Method of orchard irrigation. Orchards may 

 be irrigated by any of the methods already discussed. In 

 early irrigation days, the flooding method was most 

 generally employed in orchards, and even today this 

 method is extensively used in California and some other 

 localities. When the flooding method is used today, 

 earth ridges are formed half way between the rows of trees, 

 making a set of squares with a tree in the middle of each. 

 These are filled with water as described in Chapter X. 

 The trees themselves are protected from direct contact 

 with the water by earth heaped around the trunks. This 

 method has the advantage that it covers the whole sur- 

 face of soil and insures a uniform penetration of water, 

 which has a beneficial effect upon the soil and soil organ- 

 isms. However, much work attends the throwing up of 

 the ridges and the orchard is made unsightly and difficult 



