8 
The Effect of Climate 'and, Weather on the Soil. 
soil is curiously mottled in appearance ; it forms hard white 
lumps round which black water collects or dries to leave a 
black crust behind. It is hard on top but often mushy helow 
especially in irrigated regions, and after you have kicked away 
the surface layer® you come into a thick stodgy clayey mass. 
Irrigation, drainage, and treatment with gypsum have done 
much to reclaim these lands. e . , 
Moving eastwards and northwards there is a rather moiste 
belt with more grass and less alkali, but the vegetation is still 
wiry or leathery and gives rise to organic matter characteristic 
in quality but sparse in amount. These are the steppe soils 
which can be found in parts of the Western States and 
Alberta. Alkali spots still occur, and Fig. 2 shows one taken 
by Dr. Alway on a farm on the Platte River, Nebraska. 
Still further eastwards and northwards is a zone or higher 
rainfall where the conditions were such that organic matter 
accumulated to a very marked extent in the soil. Here arose 
the wonderful black soils on which so much of our wheat is 
grown, especially developed in Manitoba, Saskatchewan, and 
Alberta, in Minnesota and other Middle Western States. 
Elsewhere, however, the black soil is not seen but the 
loess, a windcarried soil derived from glacial drift and mingled 
with calcareous debris but without the large amounts of organic 
matter of the black soils. These give the deep rich soils found 
in Eastern Nebraska, Iowa and parts of the Mississippi valley. 
All these areas are characterised by cold, clear winters and hot 
dry summers. In the aggregate the rainfall may be high, but 
its distribution is not always favourable to maximum crop 
production. These areas are in the main treeless, homing 
still further east into the regions of wood and forest where the 
climatic conditions approximate more closely to our own, the 
soils also resemble ours in England. 
A wholly different type of soil, known as the tundra, is 
found in the far north in the barren lands beyond the regions 
of our accustomed vegetation. It is like a peat bog with a 
permanently frozen subsoil and carries only mosses, lichens, 
and dwarf csespitose shrubs. ■ 
Any other continental area can similarly be divided into 
zones corresponding broadly with climatic zones. In Russia, 
for example, white desert soils poor in organic matter but 
often containing alkali are to be found in the dry Caucasian 
region ; further north under a limited rainfall of 8-12 inches 
occur the brown steppe soils, their deeper colour indicating 
their higher content of organic matter ; pushing still further 
north a belt of chestnut coloured soils is found stretching 
away in a north-easterly direction from Podolia in the south- 
west across Little Russia to Samaria and Orenburg in the east. 
