52 



Strawberry-Growing 



Table I. — Plant- food in Strawberries 



Plant-food withdrawn from the soil. 



The strawberry draws little plant-food from the soil 

 as compared with a crop of corn or wheat. L. L. Van 

 Slyke estimates that the approximate amounts of plant- 

 food constituents used in producing a crop of 5000 pounds 

 an acre, are 7.5 pounds of nitrogen, three pounds of phos- 

 phoric acid and twelve pounds of potash.^ A w^heat 

 crop of thirty-four bushels an acre with straw included, 

 removes about thirty-eight pounds of nitrogen, thirteen 

 pounds of potash and nineteen pounds of phosphoric 

 acid. This withdrawal of plant-food is very small com- 

 pared with the total quantity present in ordinary soils. 

 One of the best strawberry soils in Missouri, according to 

 W. L. Howard, contains, in the top seven inches, 3800 

 pounds of nitrogen, 1430 pounds of phosphorus and 

 7990 pounds of potash.^ A large proportion of this is 

 not immediately available, hence strawberries on this 

 soil profit by an application of 300 pounds of acid 

 phosphate an acre, according to experiments conducted 

 by the Missouri Experiment Station. 



1 "Fertilizers and Crops," p. 694. 



2 Report Mo. Hort. Sec, 1907, p. 267. 



