178 PROFITABLE DAIRYING 



thing; keep a few cows, raise legumes for feed, 

 engage in diversified farming, practice rotation 

 of crops, sell less off the farm and feed more 

 on it. In this way he will preserve for himself 

 more of his most valuable asset, the fertility of 

 the land. 



EXERCISES 



1. What is meant by a three-year rotation? 



2. Outline a five-year rotation. 



3. Which removes the greatest amount of fertility 

 value from the soil, oats or tobacco? 



4. How do you dispose of your milk at home ? 



5. What is done with the barnyard manure ? 



6. What is done with the crop grown on the land ? 



7. Can you suggest a better way to keep up the 

 fertility on the home farm? 



LABORATORY PROBLEMS 



XXVI. To Determine Whether "Souring" Has Any Effect 

 on the Fat Content of Milk or Cream 



Mix well a quantity of milk and sample into from 

 6 to 10 milk test bottles. Test two of the milk samples 

 at once. Allow the other samples to "sour" for a 

 week or two. Test them in duplicate at intervals of two 

 weeks. Before adding the acid break up the curd by 

 shaking the bottle. If the sample is very dry, add a 

 few cubic centimeters of water. Add sulphuric acid 

 in small quantities of five to six centimeters at a time. 



Compare results obtained with those obtained when 

 the fresh milk was tested. 



