182 IRRIGATION. 



within the last few years. This, however, can occur only 

 to a limited extent, as the physical features of the coun- 

 try, upon which the peculiarities of the climate depend, 

 must remain permanently as they are, and their effects 

 must of course continue with them. But the intensity 

 of the drouth, and of the hot, dry winds, will probably 

 become ameliorated more and more, as the cultivation of 

 the soil extends. 



The management of the various field crops under irri- 

 gation, calls for some judgment, and a few general re- 

 marks may be useful. 



Wheat. This will always be the main crop wherever 

 irrigation is generally used. A thorough soaking of the 

 soil, some days before it is plowed, is advisable. It then 

 turns up mellow and in fine condition for the seed. 

 Where wheat is made to follow wheat, the seed may be 

 sown upon the stubble, and a light furrow turned over it. 

 Otherwise it would be preferable to drill in the seed, and 

 immediately roll the land with a corrugated roller, fig. 96, 

 which leaves the surface covered with small channels, ad- 

 mirably fitted for watering the crop. (This roller, as 

 well as another kind for the same use, is described more 

 fully in the next chapter.) If no rain should occur, or in 

 localities where rain is not to be looked for, a moderate 

 watering may then be given before the soil has become 

 dried. This will be sufficient to start tl^e growth, after 

 which moderate waterings, at intervals of seven to four- 

 teen days, will be required, up to the time when the 

 grain is heading. Then occurs the critical period, for 

 overwatering may rust the crop ; and it is precisely here 

 that the irrigator enjoys the advantage over the farmer 

 who depends on rainfall exclusively, and frequently sees 

 his hopes and his crop blasted together by unfavorable 

 weather at the period of flowering. It may be that -water 

 will be required as soon as the grain is beginning to form, 

 but if the soil is at all moist, water may not be needed. 



