96 



FARM ARITHMETIC. 



275. How many more inches of rainfall will be needed 

 on tlie cloVer plot than on the other ? 



Influence of method on producing power of soils. 



Soils differ in producing power. The same soil often is 

 influenced in productive power by a change in the method 

 of tillage, cultivation, and treatment. 



The following results were obtained during three 

 years' growth of crops showing the influence of thorough 

 tillage. 



Tillage Increases Crop Yields. 



276. How many tons of forage were produced during 

 the three years where spring plowing was done ? 



277. Where fall plowing was done? 



278. Where both spring and fall plowing were done? 



279. What is the per cent of increase of fall plowing 

 over spring plowing? 



280. What is the per cent of increase of fall and 

 spring plowing over spring plowing only? 



281. Twenty acres of land, fall and spring plowed, are 

 the equivalent of how many acres of land spring plowed 

 only? Are thefe other savings? 



