42 SOIL AND SOIL PREPARATION 



Query. What effect on growth of crops has under- 

 drainage of a field? Does the color of soil have any effect 

 on its capacity for absorbing and holding heat ? 



Note. Where the amount of water in soil is excessive, the spaces 

 between the soil particles become filled with water to the exclusion 

 of air. Such a soil is said to be saturated. It is unfit for cultiva- 

 tion of all ordinary crops. Rice is the only cereal which can be 

 grown in very wet soils. 



31. EFFECT OF TILLING 



Object. To demonstrate the benefit of tilling the soil. 

 Apparatus. Flowerpots, soil, and seeds. 



First Method. Fill a flowerpot with coarse lumpy so 

 and another with the same soil which has been crumbled fine. 



Plant seeds of corn, squash, or other quickly germinating 

 seed. Water both alike and stand them in a favorable 

 location. In which does germination start first? Which 

 plants thrive best? How may this be explained? Why is 

 soil plowed and harrowed? 



Conclusion. What sort of soil is best adapted to the 

 germination and growth of young plants ? 



Note. Experiments in tilling the soil are better made in school 

 gardens when possible. Space in flowerpots is not sufficiently 

 large to present such exercises to the best advantage. 



Second Method. Put .equal weights of soil in two flower- 

 pots. Pack the soil down firmly in each flowerpot, then loosen 

 up about two inches depth of one. At the end of a week 

 weigh both flowerpots. Which has lost the greater amount 

 of moisture? Why? How does this exercise illustrate soil 

 tilling? 



