136 Subtropical Vegetable-Gardening 



is used, it must be sure to contain no weed seeds. It 

 should be applied several weeks before setting out the 

 onions. If both home-made and commercial fertilizer 

 are to be used, the former is plowed in, and after the land 

 has been well worked down, the latter is spread broadcast, 

 and mixed about two weeks before planting time with the 

 soil by using a cutaway harrow. In using fertilizer, " Put 

 on all you think the land can stand, then put on as much 

 more, and you will have about half enough." The pro- 

 portions should be : ammonia, 6 per cent ; available phos- 

 phoric acid, 6 per cent; potash, 9 per cent. Use a ton 

 of the above on land that is considered fertile enough for an 

 ordinary crop ; two tons may be applied on land that has 

 been cropped for several years. The following table will 

 give the amounts of fertilizer material necessary : 



POUNDS TO THE ACRE 



1600 to 3000 cottonseed meal ; or 

 700 to 1400 nitrate of soda; or 

 Ammonia . . . 100 o to 2000 dried blood ; or 



500 to 1000 sulfate of ammonia. 



Phosphoric acid . . 1200 to 2400 acid phosphate. 



2200 to 4400 kainit ; or 

 p , 360 to 720 muriate of potash ; or 



in 350 to 700 high-grade sulfate of potash; or 



700 to 1400 low-grade sulfate of potash. 



Seed. 



The Bermuda onion is recommended as being the best 

 variety for a crop in tropical and subtropical regions. The 

 best seed is grown in Teneriffe, and this should be used. 



