THE CUBA REVIEW 29 
information regarding the output of each one of the units supplying the demand is difficult 
to obtain. Estimates made by those closely in touch with the situation vary all the 
way from about 60,000 tons to as high as 120,000. 
As has already been indicated, the consumption of fertilizer in Cuba began in the 
tobacco fields of Pinar del Rio Province, Peruvian Guano being at first the only material 
employed, but later on with the introduction of chemical fertilizers by Piel Brothers, 
the demand sprang up among growers of this crop for a ‘“‘white”’ fertilizer, which has 
since persisted. Analysis of the fertilizers used in the tobacco fields and also the com- 
ponent materials used in their manufacture vary somewhat, but we believe that a repre- 
sentative analysis is 3% ammonia, 6% to 8% phosphoric acid and 3% to 6% potash, 
the quantity of potash depending in recent years upon the price at which this material 
could be provided. The materials used in the standard tobacco fertilizer are: sulphate 
of ammonia and cotton seed meal as sources of nitrogen; ground bone, single and 
double acid phosphate as sources of phosphoric acid; and high grade, practically 
chlorine free, sulphate of potash or nitrate of potash as the source of potash. A pre- 
judice has existed in the minds of nearly all tobacco growers against the use of nitrate 
of soda as a source of nitrogen for tobacco fertilization, but the result of experiments 
covering a considerable number of years in various classes of soil, not only in Pinar del 
Rio Province but also in the Partidos District of Havana Province, has shown con- 
clusively that a part of the nitrogen in tobacco fertilizers can be obtained advantageously 
from nitrate of soda. In the experiments mentioned, one-half of the nitrogen was 
obtained from nitrate of soda and one-half from sulphate of ammonia in the fertilization 
of plats which year after year gave the largest crop of tobacco of the nest burning quality. 
The quantity of fertilizer used is so much per 1,000 plants, the Cuban unit “arroba” 
being employed and the quantity varying from one arroba to one and one-half arrobas 
per 1,000 plants. An arroba is 25 pounds, and planting is so made that from 12,000 to 
17,000 plants occupy an acre. 
When citrus planting in Cuba assumed sufficient importance to entitle it to the name 
of an industry, by far the largest area planted had been in the newer richer lands of the 
two eastern provinces, Camagiiey and Oriente, but considerable areas had been planted 
in the sandy lands of Pinar del Rio Province and in the lighter clay loams of Havana and 
Matanzas Provinces, and some acreage in the poor soils of central Santa Clara Province. 
The result has been that the use of fertilizers on these lands for this crop has demon- 
strated that the results were so favorable that, taking into consideration the small total 
area planted, the consumption of fertilizer for citrus production is quite large. The 
most successful growers have, without variation, been those who have accompanied 
generous fertilization with sufficient irrigation to offset the most serious effects of our 
customary long winter drought. The fertilizers usually employed by our citrus growers 
differ in nitrogen and potash content, depending upon the age of the grove, the higher 
nitrogen content being utilized for young groves rapid growth of which is desired, and 
the more heavily potashed fertilizers being used on older producing groves, especially 
on those whose fruit, such a grapefruit, must be shipped abroad in order to find a market. 
A representative formula for the young grove not yet in full production might be given as 
5% ammonia, 6% to 8% phosphoric acid and 3% potash, while for the older fully pro- 
ducing groves a representative formula may be taken as 3% to 4% ammonia, 6% to 
8% phosphoric acid and from 6% potash up. It has become customary also among 
our citrus growers to make an application of nitrate of soda alone, usually in December 
if conditions are favorable, otherwise in the early spring, with the idea of forcing an 
early bloom, so that fruit ripening in August and September can be obtained, thus secur- 
ing the high prices paid for fruit coming into market at this off-season period. The 
success achieved by those of our growers who have been generous with their fertilizers 
and have been in position to give a limited amount of irrigation has been remarkable, 
contrasting greatly with the results of the work of those who have been parsimonious 
in the use of fertilizers and have not been in position to give the irrigation required to 
overcome the retarding influence of the dry winter months. 
