THE EFFECT OF STRONGLY CALCAREOUS SOILS ON 

 THE GROWTH AND ASH COMPOSITION OF CER- 

 TAIN PLANTS. 



INTKODXTCTION. 



Many soil troubles in Porto Rico !i])pcar to bo duo to an excess of 

 liiuo or to the acidity attending a deficiency of lime. In a previous 

 bulletin of tliis station ' attention was called to tbe action of an 

 excess of lime in rendering soils unsuitable for the cidtivation of ])ino- 

 ajjples. Besides pineapples, some other cro]:)s refxise to grow on the 

 excessively ciilcareous soUs, or else give evidence of nutritional dis- 

 turbances by tiie chlorotic appearance of their leaves. Since a con- 

 siderable portion of the arable land of P(u-to Kico is moderately or 

 excessively calcareous it is believed that uivestigations to detcrmme 

 the cause and ciu'e of these disturbances are important. As a part 

 of such Liivest.igations, a study has been made of the effect of varying 

 amounts of carbonate of lime in tlie soil u])on the growth and mineral 

 com])osition of various plants. 



Since the nutritional disturbances of some ))lants on the excessively 



calcareous soils are evidently caused by the chemical and not tlie 



physical character of these soils, it was thoiight that a comparison 



of tlie ash contents of plants grown on a normal and on a calcareous 



soil might indicate the nature of the disturbance. The data reported 



throw some light on this specific problem as well as on the more 



general subject of the effect of the soil on the ash compositionof 



))lants. 



PREVIOUS WORK. 



ON TUE INFLUENCE OF C'AKBONAJE OF LIME ON THE GROWTH OF 

 PLANTS. 



Tliere are few quantitative data on the effect of strongly calcareous 

 soils on the growth of jilants. The residts of orduiary liming experi- 

 ments, which show the effect of alterations in the soil reaction, do 

 not apply to this hivcstigation, except that plants thriving best on 

 acid soils must be expected to show a depression on strongly cal- 

 <'areous soils.' 



1 Porto R ico Sta. Bui. U. 



» Whcclcr, H. J., ct al., Rhode Island Sta. Rpts. 1S93, pp. 224-252; 1894, p. 152; 1895, p. 205; 1896, p. 242: 

 1S97, p. 202; 1S9S, p. 144; 1S99, p. 171; 1900, p. 293. Coville, F. V., U. S. Dept. Agr., Bar. Plant Indo-s. 

 Bui. 193; U. S. Dept. Agr. Bui. 6. 



(7) 



