Circular No. 6o February, 1916 



MASSACHUSETTS AGRICULTURAL EXPERIMENT STATION 



AMHERST. 



Suggestions for the Use of Fertilizers for Tobacco and Onions for 1916. 



H. D. Raskins. 



The unusually large number of requests from local farmers for 

 suggestions and advice in relation to the use of fertilizers for tobacco 

 and onions has warranted the publication of this circular. 



It is evident that the tobacco and onion growers are confronted by 

 unusual conditions. The extremely wet season of last summer must 

 have modified soil conditions by the elimination of much of the soluble 

 nitrogen and potash, as well as numerous other soluble plant food resi- 

 dues which the soil contained. The washing out of these saline 

 substances, which had accumulated during the past several years due to 

 the lack of a normal rainfall, is likely to benefit materially large areas of 

 tobacco land, altho in all probability it will be necessary to supply 

 available nitrogen somewhat more liberally than during the past few 

 years. Potash is not as readily leached out of the soil as nitrogen, yet 

 from analyses made of tobacco soils collected late in the fall of 19 15 it 

 would seem that considerable soluble potash had been lost. It is felt, 

 however, that old tobacco soils are sufficiently well stocked with potash 

 to grow good crops for a few seasons without any additional potash 

 application. 



The fertilizer manufacturers have decided upon a maximum of 2 per 

 cent potash in mixed fertilizers; the majority of the brands, however, are 

 guaranteed to contain only i per cent for which $5.00 a unit is charged ; 

 many of the companies are not offering potash in any of their mixed 

 goods. 



Fertilizers for Tobacco. 



In fertilizing for tobacco the usual practice has been, up to the time 

 of the scarcity of potash in this country, to use each year about 3,000 

 pounds per acre of a formula testing 4.50 per cent nitrogen, 3 per 

 cent available phosphoric acid and 5.50 per cent potash, this amount 



