CAMPBELL'S SOIL CULTURE MANUAL 131 



In fact it is well known that by far the larger proportion 

 of the soils of the semi-arid country is of almost unlimited 

 depth and of uniform texture. This is an advantage. 



DIFFERENCE IN THE RAINS. 



In Farmer's Bulletin 266, published by the Depart- 

 ment of Agriculture, Washington, D. C., we find also 

 some discussion of the difference in the rains of 'the differ- 

 ent sections. The Bulletin says: 



"There is an important difference in character between 

 the rains of the east and those of the west. The summer 

 rains of the west, and especially of the plains country, 

 consist largely of infrequent heavy showers. If the soil 

 be open and deep, this rain sinks deeply into the ground. 

 As previously mentioned the hot sun and drying winds 

 of the semi-arid regions rapidly 1 dry the topsoil and this 

 forms a mulch, or covering, which retards evaporation. 

 Light showers in a dry time do very little good. They 

 wet the surface, and if the water extends to the moist 

 soil below, water from below actually flows to the surface 

 over the wet soil grains, and the water of the light shower, as 

 well as some of that previously in the soil, is lost by evap- 

 orating into the air. In humid countries, where much of 

 the precipitation consists of frequent light, slow falling 

 rains, with much cloudy weather, the surface dries more 

 slowly, giving less protection to the lower soil, so that 

 much more water is lost from the soil as a whole than 

 would be the case if the same quantity of water came 

 in less frequent rains, provided, of course, the heavy rains 

 all sink into the soil." 



Bear in mind that it is practically always and ever 

 true that the soil of the semi-arid country is in the best 

 possible condition for soaking up all of the water rain 

 which falls. If it is perfectly dry down to a great depth 



