92 MISC. PUBLICATION 3 6 9, U. S. DEPT. OF AGRICULTURE 



APPENDIX 



Tables of Crop Composition 



In the following tables there is tabulated the mineral composition, 

 insofar as it is known, of the principal crops of interest in the United 

 States. The data were compiled from several hundred published 

 foreign and domestic reports and from unpublished data submitted 

 by State agricultural experiment stations and by various bureaus of 

 the United States Department of Agriculture. In every case in which 

 individual analyses have been used, reference to the source of the data 

 is given, and in addition the sources of data used in the summaries in 

 the minor-element tables are given. Thus, the reader can quickly 

 verify almost any item in which he is particularly interested. 



The data have been chosen with every possible care, and particular 

 attention was given to methods of handling the crops and to methods 

 of chemical analysis. Thus, data on forages sampled from weathered 

 materials are not included, and the results of pot tests or other artificial 

 conditions have not been compiled. Data from other compilations 

 have not been included, all data in this compilation having been 

 obtained from original sources. 



Furthermore, only analyses published on the moisture-free basis or 

 those that could be calculated from given moisture contents to that 

 basis were used. Moisture contents of forages and most vegetables 

 vary considerably after harvest, and analyses on the fresh basis have 

 little meaning unless the moisture content at the time of analysis is 

 also given. 



It was desirable in many instances to discard certain data that 

 seemed to be entirely out of agreement with most of the known results. 

 This was ordinarily done, however, only where a large number of values 

 were available for comparison. Many extremes have been included 

 where the lack of data did not justify their elimination, but occasion- 

 ally in these instances the reader's attention is called in the tables to 

 data that do not seem to be reasonable. 



It is believed that the data in these tables should be of value to 

 nutritionists, agronomists, and others interested in the composition 

 of crops, and the descriptions of the crops and of the soils and the 

 fertilizers used have been made with this in mind. 



