162 On the Composition and Nutritive Properties of Swedes, 
growth, but at the same time has a tendency, if too liberally 
used, to develop over-luxuriance in the tops. This is more 
particularly the case if the dung is derived from fattening- 
beasts liberally fed upon oilcake and artificial food rich in 
nitrogenous constituents. If the autumn turns out fairly dry 
and mild, the roots on highly manured land continue to grow 
vigorously ; and if the weather in September and October 
continues warm and dry, a heavy weight and fairly ripe roots 
result from the liberal use of rich dung. But should the 
autumn be cold and wet, the roots do not get sufficiently ripe ; 
they remain watery, deficient in sugar, and altogether less 
nutritious than they would have been had a more moderate 
dressing of dung been put upon the land. The chief cause of 
the immature condition and low feeding-quality of roots grown 
with an excessive dressing of rich dung is due to the large 
amount of ammoniacal and readily available nitrogenous matters 
which is supplied in the dung. Numerous field experiments 
have shown that the peculiar tendency of salts of ammonia and 
readily available nitrogenous matter is to produce luxuriant leaf 
development and vigorous and prolonged growth, which in our 
fickle climate frequently results in a more or less immature con- 
dition of the roots. There is thus danger of over-manuring root 
crops, and the desire to produce heavy crops not unfrequently 
leads practical men not to appreciate sufficiently this danger. 
For the same reason Peruvian guano, sulphate of ammonia, 
nitrate of soda, and nitrogenous manures in general, should be 
applied to root-crops in moderation, especially on strong land. 
On the other hand, superphosphate of lime and similar purely 
phosphatic manures have a tendency to induce early maturity, 
and to contribute in a great measure to the production of sound 
nutritious roots of good keeping qualities. Instead of growing 
swedes with very heavy dressings of dung, I believe it will 
be found, as a rule, more economical to apply to the land a 
moderate dressing of dung in the autumn, and to drill in the 
seed in spring with 3 to 4 cwts. of superphosphate on heavy 
land, or on light soils with a mixture of 3 cwts. of superphosphate 
and 2 cwts. of guano ; or 3 cwts. of superphosphate, 1 cwt. of 
nitrate of soda, and 2 cwts. of salt. 
If swedes have to be manured entirely with artificials, am- 
moniacal or nitrogenous manures may be used with advantage 
in larger proportions, in conjunction with superphosphate, than 
on land which has been previously dunged. In that case nitro- 
genous manures, such as guano or sulphate of ammonia, should 
be sown broadcast and not be drilled in with the seed, for all 
ammoniacal manures, contrary to the generally received opinion, 
have a tendency rather to check than to promote the growth of 
