The climate is hot and dry, the rainfall being too small to influence climatic conditions.
This evidence of a gradual process of upheaval still in action may throw some light on the physical (especially the climatic) changes which must have passed over that part of Asia since Balkh was the " mother of cities," the great trade centre of Asia, and the plains of Balkh were green with cultivation.
In regions where climatic conditions are favourable, cotton grows more or less successfully on almost all kinds of soil; it can be grown on light sandy soils, loams, heavy clays and sandy " bottom " lands with varying success.
The nature of the soil appears, however, to be of secondary importance, provided that it is able to hold moisture and that climatic conditions of high and even temperature with considerable rainfall and absence of wind are satisfied.
Whilst, however, the plant adapts itself to a great variety of climatic conditions and will grow on almost all kinds of soil, the flavour and quality of the produce are profoundly affected by variations in these two factors.