302 



THE HOME GARDEN 



up the soil particles so that water can soak out the ma- 

 terials which the plants use for food. It allows the air to 



Cultivation in the Central West. 



pass through the soil, and by making a loose mulch or 

 broken surface (see diagram below) water is more easily 

 kept in the garden soil. 



PLOWED SOIL 



I NOT-.: HARROWED 



.SUBSOIL -MSppp jalte,' SUBSOIL f 



HH I 



A B 



A, Soil as left by the harrow. B, The same soil packed by rain. (After Mayne 

 and Hatch.) 



Mineral materials in the soil. While soils differ a good 

 deal in their mineral content, there are certain min- 



