SOILS 



BARREN SAND SOILS 

 Material 



Organic Matter 



Fine Gravel, 2-1 mm 



Coarse Sand, 1-5 mm 



Medium Sand, -S-.25 mm 



Fine Sand, .25-.! mm 



Very Fine Sand, .I-.O5 mm 



Silt, .os-.oi mm 



Fine Silt, .oi-.oos mm 



Clay, .OO5-.OOOI mm 



Per cent 



3-75 



1.40 



27.92 



31.64 



17.48 



12.66 



1.90 



0.86 



I. XI 



The above percentages tell their own story : they show 

 the classes in which these soil particles fall. In other 

 words, as much as 84 per cent, of these barren soils is com- 

 posed of sand. You can note readily the small percentage 

 of silt, humus, and the clay components. Were plant 

 food to be added, it would be lost as quickly as the water 

 that falls as rain. 



Soils containing so high a per- 

 centage of sand may be used for a 

 limited number of crops, and then 

 only when reen forced with or- 

 ganic matter, chemical fertilizers, 

 and water at frequent intervals 

 (by irrigation, if possible). 



What special soil types show. 

 To develop this idea further, let 

 us take the analyses of a few soils 

 where certain standard crops grow 

 to their fullest perfection, not for 

 a single year, but for a time of 



sufficient duration to give these soils the right to the name 

 of model examples of their type or class. 



SECTION OF THE SOIL 



SHOWING AIR SPACES 



AND PARTICLES 



