60 
Absorption of Pliosphate of Lime ; and 
superphosphate is the cause of the diseases to which roots of 
late years have become more exposed than formerly. 
^\ hether turnips and swedes are really now more liable 
than formerly to contract disease it is not for me to decide ; pro- 
bably the more extended growth of green crops has something 
to do with this generally received opinion. But there can he. 
but little doubt that roots are often grown on some soils naturally 
most unsuited to green crops, and that on others farmers often put 
too much reliance on the use of superphosphate. 
Noticing onlv the final failure in the crop, and not the first 
effect which superphosphate did produce, practical men are apt 
to ascribe the failure to the superphosphate, and not to the great 
poverty of the soil in other mineral and organic constituents not 
supplied by superphosphate. This, like other special manures, 
should only be used exclusively in special cases, and not on 
land in w hich a general deficiency sugo-ests at once the simul- 
taneous application of another more complex and general manure 
like farmyard-manure. There are many sandy soils on which 
roots cannot be grown with superphosphate alone, for the simple 
reason that these soils do not contain the proper amount of potash 
and lime or organic matters which is needed by the turnip- 
crop. 
In a former contribution to this Journal I mentioned an 
instance of failure from the use of superphosphate, which is so 
much to the point that I may be allowed to refer to it tigain. 
It occurred on a farm at Ashton Kevnes, a village about six 
miles from Cirencester. On visiting this farm, Mr. Plumbe, the 
occupier, directed mv attention to a field of considerable extent 
on the slope of a hill. Surrounded by a tract of country visibly 
abounding in limestone-gravel, the field on the slope and top of 
the hill presented a striking contrast, even to a superficial 
observer, with the fields at the base of the hill. These were 
moderately stiff, full of limestone-gravel, and the root-crops on 
them looked healthy, promising a fair average yield. The 
elevated field in question, on the contrary, was sandy in the 
extreme, apparently contained but little clay, no limestone-gravel 
whatever, and the turnips on it were affected by anbury to such 
an extent as I never witnessed before. 
There was hardly a sound turnip to be seen, except on two 
isolated spots. With this exception, the whole of the roots were 
so much injured by the disease that it was not considered worth 
while to send sheep over the field. 1 was informed tliat, after 
the turnip-seed was drilled in with superphosphate, the young 
plants came up well, looked remarkably strong and healthy up 
to the time of singling, and promised to be a very fine crop. 
