EXTENSION" COURSE IN SOILS. 89 
10. If 300 tons of manure are produced on the farm annually, in problem 8, how 
can this manure be most economically used? 
11. A man owns the W. | of the NW. \ of a section of land. On the north end 20 
acres are taken out of the crop-producing portion of the farm on account of woodlot, 
farm buildings, and railroad right of way. Each year this man raises 20 acres of corn, 
20 acres of oats, and 20 acres of hay (5 of alfalfa and 15 of a mixture of clover and a 
little timothy). A 3-year rotation is practiced, with the exception of alfalfa, which 
is left four years. Draw a diagram showing how this man rotates his crops. 
12. A farm located in the S. \ and the NE. I of the SE. ^ of a section contains 20 acres 
woodlot in the W. half of the NE. J, 10 acres of hillside subject to erosion in the NE. \ 
of the NE. |, and 20 acres of acid sandy soil at the west end of the S. \. Five acres in 
the SE. corner of the farm are taken out for buildings. Plan a system, or systems, of 
rotation on this farm when the following crops are to be raised each year as far as 
possible: 30 acres of corn, 20 acres of oats, 10 acres of barley, 10 acres of alfalfa, 15 
acres of clover, and 30 acres of pasture, including woodlot. 
REVIEW QUESTIONS, LESSON XII. 
1. Give specific reasons why it is best to grow more than one crop on a farm. 
2. Name five advantages derived from a crop rotation. 
3. What is understood by tilled crops? Intertilled crops? 
4. Explain how grasses are better adapted to humus formation than cultivated 
crops. 
5. Name the essential parts of a rotation. 
6. What determines largely the kind of rotation a farmer may practice? 
7. Discuss the rotation best suited to a sandy farm. 
8. Suggest a 6-year rotation for a dairy farm. A 5-year rotation. 
9. On. a farm consisting of sand and marsh, where can manure be used to best ad- 
vantage? Why? 
10. Discuss the relation of different types of soils in a farm to crop rotations. 
11. Outline a cropping system and a plan of fertilization for grain farming whereby 
the fertility of the soil of the farm may be maintained or increased. 
12. Compare grain farming with live-stock farming from the soil-fertility stand- 
point. 
13. What is the most important problem in connection with permanent agriculture. 
14. Are you now able to figure out accurately a profitable system of cropping and 
fertilization whereby the fertility of your farm will gradually be increased? 
