BULLETIN OF THE BUSSEY INSTITUTION. 51 
No. 4.— On the Composition of Buckwheat Straw. By 
F. H. Storer, Professor of Agricultural Chemistry. 
FRroM several of the published tables of the average composition of 
the ashes of plants,* it would appear that the proportion of phosphoric 
acid in the ashes of buckwheat straw is very much higher than it is 
in the ash of other kinds of straws. At first sight, it would seem as 
if this difference might be due to the dissimilarity of the buckwheat 
plant to the other plants whose straws are enumerated in the tables. 
The close botanical relations of buckwheat with various plants that 
are commonly classed as weeds, and the fact that the ashes of many 
weeds contain a good deal of phosphoric acid, tend to support this 
idea. But the force of the argument is greatly diminished by the 
facts that the straws of pea, bean, rape, and poppy plants, as well as 
those of the cereals, are included in the tables, and that no one of these 
straws yields ashes that contain nearly as much phosphoric acid as has 
been allotted to the ash of buckwheat straw. Moreover, the analyses 
that have indicated the presence of large amounts of phosphoric acid 
in the ashes of weeds were analyses of the ashes of entire. plants ; 
that is to say, of the ash of leaves, stems, flowers, and often seeds, 
that had been burnt all together: they do not refer to the ashes of mere 
straw, and they have consequently no very immediate bearing upon the 
present inquiry. 
In seeking for an answer to a student’s question, as to the meaning 
of the current statement that buckwheat straw is so exceptionally 
rich in phosphates, I noticed that the figures given in the tables just 
referred to, depend solely upon six analyses of buckwheat stalks (free 
from leaves), of exceptional character, that were made by Wolff,f in 
connection with some experiments of his on the influence of inorganic 
fertilizers upon the growth of plants. These analyses, though evidently 
excellent in themselves, are plainly unfit to give the average composi- 
tion of buckwheat straw, or to justify a belief that such straw is 
ordinarily highly charged with phosphates. In order to obtain some 
* See, for example, the tables in Johnson’s‘‘ How Crops Grow.” New York, 
1868, pp. 153, 378. 
t “Journal fiir praktische Chemic,” 1850. 51. 38; and 1851, 52. 102. 
