26 FOOD FOR PLANTS 



Clay loam runs between twenty-nine (29) to 

 thirty-nine (39) per cent, of sand, and a clay soil 

 would be described as a soil containing about sixty- 

 one (61) per cent, or more of clay. 



A very rich soil may be described as a soil con- 

 taining 2 per cent, of lime and 1.80 per cent, of 

 potash and from .02 to .10 per cent, of sulphuric acid, 

 in the form of sulphate, and from .10 to .30 per cent, 

 of phosphoric acid, in the form of phosphates, with 

 humus running from 1.20 per cent, to 2.20 per cent, 

 and Nitrogen from .20 to 1 per cent. 



According to French authorities a good soil would 

 contain .20 per cent, of Nitrogen and .20 per cent, of 

 phosphoric acid, in the form of phosphates, and .30 

 per cent, of potash. Anything above these figures 

 would be called very rich. 



Very poor soil would average about .08 per cent, of 

 Nitrogen and .08 per cent, of potash and .08 per cent, 

 of phosphoric acid with humus of .30 per cent. Any- 

 thing less than these figures would be very poor 

 indeed. 



The pounds of available fertility are reckoned to 

 be contained within eight (8) inches of the surface. 

 The weight of an acre generally would rijn about 

 two thousand (2,000) tons. 



