REVIEW QUESTIONS 337 



289. What is the essential point to observe in the manuring of 

 potatoes? 290. What kind of manuring is required by sugar beets ? 

 291. Why should the 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, and 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 important princi- 

 ples 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 humus be considered in a rota- 

 tion? 301. What is the object of growing crops of dissimilar feed- 

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

 advantage? 303. How is decline of soil nitrogen prevented by 

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

 crops and their cultivation influence the mechanical condition 

 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 344? 313. Is it essential that all elements re- 

 moved in crops 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 



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