CROPS. 85 



Portugal and Italian onions are duo to their manner of 

 growth in which irrigation is extensively used. The crop 

 should be planted in rows between which water is flowed, 

 in broad, shallow channels made with a hoe. The water 

 should not come in contact with the bulbs, nor should 

 the earth be thrown upon them in making the furrow. 



Potatoes. To grow common potatoes under irrigation, 

 with success, needs caution and judgment. As the qual- 

 ity of the tubers depends greatly upon the supply of wa- 

 ter, judiciously regulated with regard to the character of 

 the soil, some care must be exercised as to the quantity. 

 Upon light soils the water is given only at intervals of 

 nine or ten days, and upon heavier soils, which are more 

 retentive, fourteen days elapse between the waterings. 

 As soon as the soil is sufficiently dry after watering, the 

 surface should be cultivated, which will cause the moist- 

 ure to be better retained. A system of drills, or of beds 

 slightly raised, is used for this crop, the water being given 

 in broad, shallow furrows, made with the hoe at the time 

 of cultivation. When the plants nearly cover the ground, 

 as they should do at the time of blossoming, the final 

 watering is given. No further cultivation should be given 

 after this period. 



Peas. As this crop is generally sown in rows upon a 

 flat surface, the mode of watering should be suited to 

 this method of planting, and it may be either by a sys- 

 tem of beds, fig. 6, or of shallow furrows made between 

 the rows with the hoe at the time of cultivation. As this 

 crop flowers and seeds during a lengthened period, it may 

 be irrigated without regard to the flowering, care of course 

 being taken to keep the soil only in a healthful state of 

 moisture. 



Tlie Small Crops. Small crops, such as lettuce, rad- 

 ishes, etc., are more conveniently cultivated in beds of 

 the form shown in fig, 6, over the surface of which the 



