Vegetables with Edible Leaves or Stems 103 



of nitrogen may be cut down accordingly. In a coldframe 

 or seed-bed, use a pound for every twelve square feet. 

 The following amounts of materials will give about the 

 quantity of each element called for in the formula : 



Pounds to the Ackb 



r 600 to 1200 cottonseed meal ; or 

 Ammonia . . . . < 250 to 500 muriate of soda ; or 

 I 200 to 400 sulfate of ammonia. 



Phosphoric acid . . 600 to 1200 acid phosphate. 



Potash . 



900 to 1500kainit; or 



200 to 250 muriate of potash ; or 



200 to 250 high-grade sulfate of potash ; or 



400 to 500 low-grade sulfate of potash. 



The general formula is applied broadcast over the field 

 and worked in thoroughly a week or so before planting 

 out. After the plants are nearly half-grown, a liberal 

 application of nitrate of soda or nitrate of potash may be 

 given. The quantity to be used will range from 100 to 

 several hundred pounds to the acre, depending on circum- 

 stances. If heavy rains occur, a second application may 

 be necessary. 



Irrigation for lettuce. 



To make lettuce-growing certain and profitable, it is 

 necessary to have some means of applying water. When 

 conditions permit sub-irrigation, this system is to be pre- 

 ferred ; when this is not practicable, an overhead system 

 may successfully be employed. The amount of water to 

 be used will vary greatly with the character of the soil 



