44 



THE FIRST BOOK OF FARMING 



Which soils have greatest power to hold the water 

 which enters them? 



Experiment. Use the same or similar apparatus 

 as for the last experiment. After placing the cloth 

 caps over the ends of the tubes label and care- 

 fully weigh each one, keeping a record of each ; 

 then fill them with the dry soils and weigh again. 

 Now place the tubes in the rack and pour water in 

 the upper ends until the entire soil is wet; cover 

 the tops and allow the surplus water to drain out; 

 when the dripping stops, weigh the tubes again, 

 and by subtraction find the amount of water held 

 by the soil in each tube; compute the percentage. 

 It will be found that the organic matter will hold 

 a much larger percentage of water than the other 

 soils ; and the clay more than the sand. The tube 

 of organic soil will actually hold a larger amount 

 of water than the other tubes. (See also Fig. 25.) 



In the experiment on page 40 we noticed that 

 the sand took in the water poured on its surface 

 and let it run through very quickly. This is a fault 

 of sandy soils. 



What can we do for our sandy soils to help them 

 to hold better the moisture which falls on them and 

 tends to leach through them? For immediate effect 

 we can close the pores somewhat by compacting 

 the soil with the roller. For more lasting effects, 

 we can fill them with organic matter. 



Which soils will hold longest the water which 

 they have absorbed? Or which soils will keep 

 moist longest in dry weather? 



