490 
Injluence of Climate on Cultivation. 
luxuriant growth than nitrogenous manures alone, which, in such 
circumstances, should be somewhat sparingly used. 
Mangold-wurzel. — This plant appears to stand at the head of 
all our green crops, with respect to its capabilities of producing 
food for stock. The climate of the south of England is ad- 
mirably suited for growing it in perfection. There, under 
liberal treatment, it can be made to produce more than double 
the weight of roots that any of the varieties of turnips will do 
with the same amount of manure. For, like all other annual 
plants which attain to large dimensions, a quantity of manure 
must be applied corresponding to the amount of produce. To 
raise a maximum produce, therefore, the land requires to be little 
else than surfeited with manure. 
The effects of those climatic agencies which we have already 
traced, in the culture of the cereals, are all still more distinctly 
exhibited by this plant. In the south the high temperature of 
summer, instead of hastening the formation of flowers and seeds, 
lengthens out its period of growth to that of a true biennial. 
It is patient under a high temperature, which imparts length of 
life, as w ell as increased vigour to take up and assimilate a large 
amount of food. 
In Jersey and the southern counties of England, the seed is 
committed to the ground in April. On deeply-cultivated and 
highly-manured soils the plants show little tendency to flower 
during the summer. The whole vegetative powers of the plant 
are directed to the formation of leaf and bulb, until they are 
arrested by the colds of approaching winter. These powers, as 
is well known, are proportioned in a great measure to the tem- 
perature and the period over which they are extended. The 
produce, therefore, of mangold-wurzel in Britain is, in all pro- 
bability, greatest when the mean temperature is highest. The 
author of a report in the last number of the Journal mentions a 
well-authenticated case of seventy tons to the imperial acre being 
produced in Jersey. 
The produce of mangold diminishes in Britain as the latitude 
becomes higher. To grow even moderate crops a much more 
copious application of manure is required, the vitality of the 
plant being weaker in consequence of the lower temperature. This 
want of vigour in the cooler climate is indicated by the larger 
number of the plants that form flower-stalks. At an elevation of 
600 feet in Scotland it is not uncommon to find nearly one-half of 
the plants seeding, and in the warmest parts of that country this 
tendency is complained of. The only counteracting influences 
that can be brought into play are deep culture and more than 
liberal manuring. For, with respect to mangold as to cereals and 
