AIR IN SOILS 69 



process already mentioned, air passages are formed in 

 the soil. Animal manures exert an influence on the texture 

 of the soil, which enlarges the pore space. Applications of 

 lime affect the structures of certain soils very materially, 

 causing a rearrangement of the soil particles in such a 

 way as to open the soil to an appreciable extent. 



