36 ELEMENTARY AGRICULTURE 



dishes, and pour into each from the top the same 

 amount of water. When it soaks out of sight pour in 

 more. Use your graduate for this, so that you will get 

 exactly the same amount of water in each tube. Which 

 soil holds water best? Which soil allows it to soak 

 through most rapidly? 



Free Bulletins, U. S. Dept. of Agriculture. 



Bureau of Soils. 



Circular No. 4. Soils of Salt Lake Valley, Utah. 

 Circular No. 8. Reclamation of Salt Marsh Lands. 

 Circular No. 13. The Work of the Bureau of Soils. 



Table IV. 

 Table showing fertilizing substances in average soils: 



POUNDS PER TON. 



Phosphoric 



Soil. Nitrogen. Acid. Potash. 



Loam 7 Ibs. 3 Ibs. 8 Ibs. 



Clay 3 Ibs. 3 Ibs. 15 Ibs. 



Drift 3 Ibs. y 2 Ib. 6 Ibs. 



Sand i Ib. 2 Ibs. 5 Ibs. 



(Adapted from Stockbridge.) 



Problems. 



1. Suppose soil is cultivated to the depth of 4 in. 

 How many cu. ft. of cultivated soil per sq. ft. of area ? 

 Per sq. yd. ? Per sq. rod ? Per acre ? 



2. If a cu. ft. of soil weighs 75 Ibs., how many Ibs. 

 of cultivated soil per sq. yard? Per sq. rod? Per 

 acre? 



