26 4 



SOILS AND FERTILIZERS 



cloth. Fill the tube with sandy soil (No. i). Compact the soil 

 after the addition of each measured quantity of soil by allowing the 

 weight from the compaction machine to drop twice from the 12 

 inch mark. 



Fig. 38. Capillary Action of Water on Soils. 



In a similar way, fill a second and a third tube respectively with 

 clay and loam ; then immerse the lower ends of the tubes in a 

 cylinder of water and support the tubes, as shown in the illustra- 

 tion. Measure each day for one week the height to which the 

 water rises in the soils. If desired, three additional tubes filled 

 loosely with the soils can be used, and the influence of compaction 

 upon the capillary rise of water in the soils noted. 



Experiment No. 5. 

 Influence of Manure and Shallow Surface Cultivation Upon the 



Moisture Content and Temperature of Soils. 

 Weigh and fill four boxes, each a foot square and a foot deep, as 



