CAUSE OF LIME-INDUCED CHLOROSIS AND AVAILABILITY 

 OF IRON IN THE SOIL 



By P. L- GiLE, formerly Chemist, and J. O. Carrero, Assistant Chemist, Porto Rico 

 Agricultural Experiment Station 



CAUSE OF LIME-INDUCED CHLOROSIS 



INTRODUCTION 



Some years ago a study was made of a chlorosis of pineapples that 

 occurred on certain soils in Porto Rico (12). 1 The particular type of 

 chlorosis was confined to calcareous soils and seemed to be induced by a 

 disturbance in the mineral nutrition of the plant. This disturbance 

 appeared to consist in a lack of iron in the plant ash or in a diminished 

 amount of iron combined with an increased amount of lime. Con- 

 siderable work has since been carried on to determine more exactly the 

 manner in which carbonate of lime in the soil induces chlorosis in the 

 plant. The work comprises a number of direct experiments on the cause 

 and cure of chlorosis as well as general studies in plant nutrition under- 

 taken to gain information necessary for interpreting results obtained in 

 the experiments on chlorosis. Since the more general work on plant 

 nutrition has been published elsewhere, only the results will be referred 

 to here. 



In the following pages the more important facts already established 

 concerning the cause of lime-induced chlorosis are given, together with a 

 full report of certain experiments on this subject hitherto unpublished. 



EVIDENCE THAT CARBONATE OF LIME MAY INDUCE CHLOROSIS 



Evidence that carbonate of lime produces chlorosis in certain plants 

 naturally falls into two classes, the results of soil surveys and the results 

 of direct tests with natural or artificial calcareous soils. These two 

 classes of evidence will be considered separately. 



RESULTS OF SOIL SURVEYS 



Ecological studies of calciphilous and calcifugous plants. — 

 Under the heading of soil surveys, reference should be made to the 

 extensive literature on calciphilous and calcifugous plants. This litera- 

 ture, of which Roux (39) gives a complete bibliography up to 1900, 

 consists chiefly of observations concerning the confinement of certain 

 plants to calcareous or noncalcareous soils. While most of these 



1 Reference is made by number (italic) to "Literature cited," p. 59-61. 



Journal of Agricultural Research, Vol. XX, No. 1 



Washington, D. C Oct. 1, 1930 



uz Key No. B-16 



(33) 



