9 
Th e Effect of Climate and Weather on the Soil. 
Above this again comes the famous belt of black earth, the 
Tchernozem, the nearest European approach to the black soils 
of the western prairies, and like them devoted largely to the 
cultivation of wheat ; these are found in Hungary, and continue 
north-easterly through the West Russian province, Volhynia, to 
the Government of Perm. Further north these are succeeded 
by the Podsols, white, poor, acid soils in a cold wet belt still 
left in forest ; and finally above them come the tundra soils, 
acid, treeless, carrying only lichens and moss. 
Even in England indications of climatic zones can be 
traced, although in the main our soils would fall into one 
great group of woodland origin. But in the dry eastern 
counties some of the heaths are distinctly steppe-like in 
character, while in the wet high-lying districts of the north 
occur moorland soils entirely different from the clays, loams 
and sands of the midlands and the south. 
We cannot now go into a detailed description of these 
various soils ; the point of immediate importance is that the 
very marked and unmistakable differences in the soils are 
the result of the climatic conditions to which they have been 
exposed. 
The Effect of Weather on the Soil. 
Climate, as we have seen, plays a great part in determining 
the general character of the soil, but every farmer knows that 
a soil may often deviate a good deal from its general character, 
and exhibit tolerably ivide variations from year to year. The 
broad character is set by climate, but the variations are the 
result of season or weather, which may vary considerably 
within the rather wide and vague limits of climate. These 
effects are different in character from those we have been 
studying, and before passing on to them it is necessary to get 
some general idea of the state of things in an ordinary fertile 
soil. 
The various mineral particles, the calcium carbonate, 
phosphates, &c., and the organic matter are on the whole 
well mixed up together to form a porous mass of which about 
60-80 per cent, is solid while 20-40 per cent, is pore space. 
This space, however, is not actually empty but contains a 
varying amount of water : sometimes it is completely filled, 
but more usually only about half to two-thirds is so occupied, 
leaving the remainder filled with air. In a wet season the 
pores are pretty completely filled with water ; in a dry season 
they are more nearly full of air. 
The various changes going on in the soil in consequence of 
chemical and bacterial processes result in the formation of a 
