CHAPTER II. 



IRRIGATION AND ROTATION OF CROPS. 



Irrigation is generally considered unnecessary in this sec- 

 tion, since we raise fair and even abundant crops nearly every 

 year without its aid, but in almost any season there are peri- 

 ods when if water could be applied to growing crops it 

 would improve them. It will seldom, if ever, pay to irrigate 

 ordinary farm crops if it is necessary to pump the water 

 used. In order to have irrigation practical for farm ci*ops, 

 the water should be carried and distributed on the land by 

 the force of gravity. It may pay to pump water to irrigate 

 some garden crops if the conditions are favorable and the 

 work is done intelligently. In this section irrigation should 

 be used to supplement the rainfall, which should ordinarily 

 be kept from running off the surface of the land by every 

 possible precaution. 



Mulching the surface of the soil is practicable only around 

 trees and in the case of a very few garden crops, such as 

 strawberries and raspberries. The intelligent use of mulch 

 on land in well known cases has caused the soil under it to 

 hold an amount of water equal to thirty-three per cent more 

 than was retained in soil near by not mulched, the amount 

 in one case being equal to an increase of over two quarts of 

 water to every cubic foot of soil, or to an increase of over 680 

 barrels in the upper one foot of soil of one acre. If this 

 amount of water had been applied at the critical stage in the 

 growth of some crops suffering for moisture, it might have 

 made a success of what would otherwise have been a failure. 

 Where practicable, it is always desirable to have a good 

 mulch on land that is watered, since it retards evaporation 

 and prevents the surface soil from baking. 



Cultivation of the land prevents evaporation and so saves 

 the moisture in it. In one instance the amount of increase of 



