SOIL FERTILITY 321 



most economical and satisfactory method of spreading man- 

 ure is by use of the manure spreader. This machine saves 

 labor, and distributes the manure more evenly than is pos- 

 sible by hand. 



The amount of manure to be used will depend on the 

 strength of the manure and the condition of the soil. Five 

 tons to the acre is a light application, ten or twelve tons 

 average, and twenty tons a heavy application. 



TOPICS FOR INVESTIGATION 



1. Has the yield of the principal crops increased or 

 decreased in your region within the last ten or twenty 

 years ? To make sure of this, ask your father, or some one 

 who has farmed in the vicinity for some time. 



2. Are there run-down farms in the neighborhood? 

 If so, is the land naturally poor, or has it been depleted by 

 single cropping or poor methods' of farming? Learn the 

 history of all such farms as accurately as possible, with ref- 

 erence to cropping, rotation, manuring, and so on. 



3. Based on the figures given in section two, what was 

 the approximate value of the manure produced on your 

 home farm last year? (See p. 318.) 



4. What care is given to saving the manure on your 

 home farm? Is it collected under cover? Does it ever 

 "fire-fang"? Is there a water-tight floor under the heap? 

 Should the liquid manure be saved? How closely is the 

 manure gathered up from the yards? What is the method 

 of distributing it on the fields? How many loads are used 

 to the acre? 



5. How much hay, oats, corn and other farm products 

 were sold from your home farm last year? What was the 

 approximate manurial value loss to the farm ? 



3. Green Manuring 



As already suggested, the returning of the barnyard 

 manure to the soil, no matter how skilfully done, is not 

 enough to maintain the fertility. Our soils are everywhere 

 being gradually worn out. One of the most successful 



