EXERCISE 136 



The forest is said to conserve the water on the hillside not only through the shielding of the soil 

 against the downpour and against evaporation, and through the action of the roots, but also through 

 the formation of the mulch, consisting of decaying leaves and other 

 organic matter. 



Problem. What is the relation of the mulch to the removal of rain 

 water ? 



What to use. Two funnels of the same size ; two test tubes or 

 bottles of the same size ; sand ; forest mulch ; absorbent cotton ; water ; 

 supports for the funnels. 



What to do. Plug the funnels loosely with cotton ; fill to within 

 an inch of the top with sand ; cover surface in one funnel with mulch. 

 Place a bottle or test tube under each funnel and pour the same quantity 

 of water on top of each. 



Record. After a few minutes note the amount of water that has 



come through the soil in the two funnels ; what does the result show regarding the relation of the 

 mulch to the water flow ? 



Questions. 1. How would you determine the drainage quality of different kinds of soil? 



2. Where would mulch be produced in the largest quantity ? 



3. In what way would a mulch be of value on a farm or in a garden ? 



4. Why cannot the natural soil cover serve as a mulch in the cultivated fields ? 



5. In what rivers has the flow of water been affected by the cutting down of forests ? 



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