Causes of Fertility or Barrenness of Soils. 203 
subsoil, and thus do not exhaust so much as might be expected. 
Beans are generally drilled much too close together, so as to 
prevent the frequent hoeings, which would prove of such advan- 
tage to the land. Peas resemble beans in their partiality for soils 
containing lime, but prefer a less retentive soil, and do not require 
it so deep. Lime seems the great necessary for the pea crop, 
and if we neither have it naturally nor add it, we must not expect 
a crop. The other cultivated members of the leguminosae, such 
as clovers, lucerne, vetches, sainfoin, &c., all flourish best on 
calcareous soils ; indeed some of them, the sainfoin for instance, 
will only grow on such soils ; the others receive great benefit by 
the addition of lime when grown in soils deficient in it. Top 
dressings of gypsum (sulphate of lime) on clover leys in spring 
are found to have the most marked effect where the soil is sandy. 
The gypsum should be sown in early morning, when the leaves 
are covered with dew ; the fine powder, in which form it is best 
applied, adheres to the leaf, and is no doubt gradually carried 
down into the soil. About 2 to 3 cwt. per acre is a sufficient 
dressing, and as the price is almost nominal, its application 
in such cases should never be neglected. The ashes of legu- 
minous plants, as we should expect, exhibit a large percentage 
of lime : thus in beans 100 parts of the ashes of the whole plant 
contain about 35 per cent, of lime ; peas a less quantity, from 
6 to 10 per cent., with large quantities of potash and soda ; sain- 
foin about 26 per cent. ; and red clover from 25 to 30 per cent. 
These analyses very clearly indicate the reason why leguminous 
plants prefer calcareous soils, and they also point out the neces- 
sity for applying small doses of lime simply as a manuring 
substance to all soils where it is deficient. Peaty soils are not 
generally adapted to the growth of corn crops, because of the 
excess of organic and deficiency of mineral matters, and their 
open nature preventing the roots getting a firm hold and sup- 
porting the plant. Oats will grow best of any corn crop ; but they 
are uncertain, especially as a first crop, too often becoming flaggy 
in straw, owing to the absorption of too much organic matter, and 
falling before ripe. Root crops succeed better, requiring a large 
quantity of such food and a very small portion of mineral matter. 
The composition of the turnip, as given by Voelcker, shows this : 
in 100 parts he finds — 
Of Water 90-43 
Sugar, Gum, &c 4*69 
Albuminous Compounds 1'14 
Vegetable Fibre 3-10 
Mineral Substances -62 
99-98 
