%Smmm 



marbles would carry is represented in the tube placed beside the 

 tumbler. The soil in the other tumbler (Fig. 2) is of the same 

 weight as the marbles in Fig. i , and it represents the 

 marbles reduced to the fineness of common sand. Its 

 capacity for holding film moisture is represented by the 

 water in the standing tube (Fig. 2). The weight of 

 material is the same in each tumbler, and the reason why 

 one holds three times more film moisture than the other 

 is due to the increase of surface that comes by dividing 

 a coarse lump into fine particles. 



The marbles represent the careless tillage of Mr. 

 Black, and the finer particles the thorough tillage of 

 Mr. White. Mr. White plows about one-third deeper 

 than Mr. Black, and thereby makes another addition to 

 the capacity of his reservoir. 



The coarse soil, as represented 1\v the marbles, will lose 

 its film moisture b}' evaporation much more readily than 

 the soil represented by Fig. 2, particularl}'- if the surface 

 of the latter is covered by fine particles representing 

 an eartli-niulch. 



4. 'Jlllage makes plant-food available. — Another differ- 

 ence in the culture given by Black and White is that the 

 better tillage enables the plant to realize more food from 

 all fertilizers which may be applied. There is also a 



benefit in making avail- 

 able some of the plant- 

 food that nature has put 

 in the soil. Broadly 

 stated, the native plant- 

 food amounts to as 



1 i 



much as can be bought ^'-■■M^^^^^^ffM^- 



in $2,000 worth of com- 

 mercial fertilizers. 

 The finer soil has anoth- 

 er advantage in afford- 

 ing a greater area for root 

 pasturage. It is not uncommon for farmers to think of plant-food 

 in the soil as in the condition of salt or sugar which is capable of 



Fig. I . — Watei^ h eld by 

 a coarse soil. 



Fig. 2. — Water held by 

 fine soil. 



