20 BULLETIN 108, U. S. DEPAETMEXI OF AGEICULTUEE. 
field. The subsoil of both good and poor soil is a light, calcareous 
clay. Both soils are alkaline in reaction, and both showed the same 
content of water soluble salts (0.03 per cent). The good sample 
contained no aldehydes, and such residue as was obtained proved 
only slightly harmful to wheat seedlings, whereas the poor sample 
contained considerable aldehydes, which proved very harmful to 
wheat seedlings in the cultural tests, reducing growth 30 per cent. 
Returning now to a discussion of Table IX as a whole, it is shown 
that the aldehyde extract is miiformly harmful to the test plants. 
This is apparent from the next to the last column of the table. 
In the third column is given the field record of the soils as to then 
productivity, the data being furnished by the collector. The garden 
soils already mentioned were all soils with which trouble of one kind or 
another had been experienced. In general, this column shows that 
the soils containing the aldehyde were also poor soils in garden and 
field, with some few exceptions. In this column is found one notable 
exception, in the Aurora silt loam, good (No. 7, Table IX). from 
^filler County, Mo. This soil contained aldehyde, whereas the cor- 
responding poor sample (Xo. 31, in Table X), from another farm, 
gave no indication of the presence of aldehyde. This observation 
was confirined by procuring a new sample from the farmer on the 
good soil six months later. The other exceptions are the Xorfolk 
very fine sandy loam, good (Xo. 8. Table IX), and the Dekalb silty 
clay loam, good (Xo. 16. Table IX), in which aldehyde was found, 
but it will be noticed that in both these cases the poor soil contained 
the aldehyde also (Xos. 9 and 17, Table IX). It would appear 
therefore that both the good and poor soil samples contained some 
aldehyde. It might be tether pointed out that in both cases the 
greater productivity of the sample designated as good is doubtless 
due to the direct fertilizing value of the applied manure, the less 
productive samples having no manure applied. That manure is not 
antagonistic to aldehyde is indicated by its presence in the exceed- 
ingly well-manured garden soils, in the same table (see notes in last 
column), as well as by some of the field results already given. 
Some of the soils given in Table X. showing no aldehydes, have 
been discussed in connection with the preceding table. The 
remainder require no further discussion here, inasmuch as no aldehyde 
was found in either the good or poor samples. 
From these two tables it is at once apparent that only a relatively 
small number of the poor soils showed the presence of aldehyde. 
which means that the poorness of many of the soils in Table X must 
be attributed to other causes, since soil infertility may be due to a 
great many factors other than the presence of toxic compounds, and 
especially any particular toxic compound. 
