282 SOILS AND FERTILIZERS 



manuring of mangels be different from that of turnips? 292. What 

 may be said regarding the food requirements of buckwheat and 

 rape? 293. What kind of manuring do hops and cotton require ? 

 294. What kind of manuring is most suitable for leguminous 

 crops ? For garden crops, for orchards, or lawns ? 



CHAPTER XII. 



295. What is the object of rotating crops? 296. Should the 

 whole farm undergo the same rotation system? 297. What is 

 meant by soil exhaustion ? 298. What are the nine important 

 principals to be observed in a rotation ? 299. Explain why it is 

 essential that deep and shallow rooted crops should alternate ? 

 300. Why is it necessary that the humus be considered in a rota- 

 tion ? 30 r. What is the object of growing crops of dissimilar feed- 

 ing habits ? 302. How may crop residues be used to the best 

 advantage ? 303. In what ways may a decline of soil nitrogen be 

 prevented by a good rotation of crops ? 304. In what ways do 

 different crops and their cultivation influence the mechanical con- 

 dition of the soil ? 305. How may the best use be made of the soil 

 water ? 306. How may a rotation make an even distribution of 

 farm labor ? 307. How are^manures used to the best advantage in 

 a rotation ? 308. In what other ways are rotations advantageous ? 



309. What may be said regarding long and short-course rotations? 



310. How is the conservation of fertility best secured? 311. Why 

 does the use made of crops influence fertility ? 312. What are the 

 essential points to be observed in the two systems of farming com- 

 pared in Section 323? 313. Is it essential that all elements re- 

 moved in crops should be returned to the soil in exactly the 

 amounts contained in the crops? Why? 314. How does manure 

 influence the inert matter of the soil ? 315. What general systems 

 of farming best conserve fertility? 316. Under what conditions 

 may farms be gaining in reserve fertility ? 317. Why in continued 

 grain culture does the loss of nitrogen from a soil exceed the 

 amount removed in the crop? 



CHAPTER XIII. 



318. Why do soils need further treatment for the preparation of 

 the seed bed? 319. Why should different soils receive different 

 methods of treatment in the preparation of the seed bed ? 320. 

 How would you determine the best treatment to give a soil for the 

 preparation of the seed bed ? 321. How do different methods of 

 plowing influence the condition of the seed bed ? 322. Why does 

 complete inversion of sod frequently form a poor seed bed ? 323. 

 How should the plowing be done to form a good seed bed? 324. 

 Why is it economy to pulverize the soil as much as possible when 

 it is plowed? 325. What effect does the moisture content of the 



