FERTILIZERS FOR PERUVIAN SOILS. 



Fertilization or fertilizing is usually limited to mean the application 

 of fertilizer to the soil. The terms fertilization, fertilizing, soil manage- 

 ment, soil rectification, should mean any treatment of the, soil whatsoever, 

 that will tend to put it into a sound healthy condition for the pro- 

 duction of any given crop, or qualities especially desired for that crop. 

 The application of fertilizers (manures, guanos, green manuring etc.) 

 is only one phase of fertilization. A soil may be put under fertiliza- 

 tion, or be fertilized (made more fertile) without the addition of a 

 pound of fertilizer. 



Fertilization by means of fertilizers is the subject here considered. 



The object of applying fertilizers to cane is to secure more sugar 

 per given area. As the cane is a gigantic grass and the sugar is con- 

 tained in its stem, the main thing is to get quantity and quality of 

 stein. If we were dealing with a plant whose leaves, fruit or seeds 

 were the parts utilized, the method of fertilizing would be quite dif- 

 ferent. Fruit trees might be fertilized as cane is with the result of 

 much wood but little fruit. 



Influence of climate and soil on fertilizers. AVith a soil and climate 

 such as Peru posesses, fertilizers are readily made available for the use 

 of plants. In most sections of Peru the growth of cane is gradual re- 

 quiring a rather long time to mature, though there are three or four 

 months in the year when the cane grows vigorously, out of propor- 

 tion to the gradual growth of the other months. This may happen 

 twice in the life of a cut. This vigorous growth is advantageous pro- 

 vided the cane can be kept growing gradually after this period, and 

 that the change from the rank to gradual growth be not too sudden. 

 This change is not caused so much by a marked lowering of temper- 

 ature as by the shorter days with consequently less sun, and the damp 

 mists from the ocean that spread a chilling blanket over the lower 

 portions of the valleys. 



If a powerful stimulant were given the cane in the warm season of 

 naturally rapid growth, the growth would be so rank that the cane 

 could not keep it up during the cool season. If a powerful stimulant 

 were added during the cool season, the possible effects on the cane 

 Would not be realized. The kind of fertilizer needed, therefore, is a 

 moderately slow acting one; such a fertilizer would be one containing 

 a good amount of plant food elements but with only a fair proportion. 



