WATER LOSS FROM MULCHED SOIL SURFACES 57 



No. 2. Remove two inches of soil and replace with cut 



straw. 

 No. 3. Remove two inches of the surface and replace 

 it in a loose condition. 

 Care should be taken to have all of the surfaces at the 

 same distance below the top of the cylinders. Why? The 

 surface of No. 3 is to be removed to the shallow pan and 

 mixed before it is returned to place. It should then be 

 stirred occasionally to keep the surface in a loose condition. 

 As soon as the mulches are in place, fill all of the water 

 jackets to the same level and weigh each cylinder. Repeat 

 the weighings every other day for a week and record the 

 weights in the accompanying table: 



Which cylinder lost the greatest amount of water by 

 evaporation? 



How does the farmer and gardener make use of soil and 

 straw mulches? 



Discussion: Any covering placed upon the surface of 

 the soil to prevent or lessen evaporation of moisture is called 

 a mulch. An artificial mulch is a covering of straw, leaves, 

 sawdust or other material of a like nature. A natural mulch 



