CULTURAL DIRECTIONS 215 



the fertilizer adapted to this crop. According lO analyses 

 made by Wolff, a ton of fresh sprouts contains 6.4 pounds 

 of nitrogen, 1.8 pounds of phosphoric acid and 2.4 pounds 

 of potash. The best fields produce at the rate of three 

 tons an acre, and this would require 19.2 pounds of nitro- 

 gen, 5.4 pounds of phosphoric acid and 7.2 pounds of 

 potash. It is very evident that the shoots themselves do 

 not abstract large amounts of plant food. To meet these 

 needs it v^fould take only 128 pounds of nitrate of soda, 

 38 pounds of 14 per cent rock phosphate and 14 pounds 

 of muriate of potash. Now, why do expert growers feed 

 their plants with such great liberality? Because other 

 factors besides the mere production of shoots must be 

 taken into account. The enormous root system and the 

 tons of tops renewed every year must be supported. 

 Again, growth of both shoots and tops must be very 

 rapid, and consequently there must be no shortage in the 

 supply of quickly available plant food. 



Nearly all growers agree that nitrogen is the most im- 

 portant element of plant food for asparagus, and while the 

 majority of them believe that it should be applied in the 

 form of nitrate of soda, some growers prefer organic 

 material, as dried blood, tankage, fish scrap or cotton- 

 seed meal. As to the best commercial fertilizer to use, 

 investigators and practical growers differ widely in their 

 recommendations. Voorhees suggests the basic fertilizer, 

 4-8-10, supplementing with heavy applications of nitrate. 

 Rolfs recommends 4-5-7. An expert New Jersey grower 

 uses a 6-7-5 formula. Many practical growers prefer 5 

 or 6 per cent of nitrogen. 



The proper time of application is a much disputed 

 question. As the leaves or elaborating organs are not 

 permitted to develop until after the cutting season, it is 

 argued by some that the proper time to apply nearly all 

 of the plant food, both stable manure and commercial 

 fertilizer, is after the cutting season, when the leaves are 



