282 IMPROVEMENT OF THE SOIL 



hence must be fed with richer food. The soil must hejinely 

 pulverized, and, so far as is practicable, freed from stones. 

 This is necessary in order that the roots may not be ob- 

 structed ; finally, they should be kept free of weeds. The 

 ground should be stirred with the cultivator and hoe. If 

 sowed in rows, as they should be, this may be easily attend- 

 ed to with the plough and cultivator, without the necessity of 

 resorting to the hoe more than once in the season. 



Theory of the action of roots upon the soil. I. They di- 

 vide it better than most crops ; 2. they deepen the soil by 

 their roots; and 3. return to the soil a larger amount of ma- 

 nure than other crops. 



Three acres of grass, at two tons per acre, will give less 

 than 9,000 lbs. to the cattle-yard, while one acre of ruta ba- 

 ga or beets, will give 36,000 lbs. or more than four times 

 as much as the three acres of grass land. It would, there- 

 fore, be economy for the farmer to raise roots merely for ma- 

 nure. But the one acre of ruta baga or beets (600 bush- 

 els) are nearly equal to three acres of hay, as food for farm 

 stock ; hence the modes by which roots improve the soil, are 

 dividing and deepening it, furnishing a larger supply of food, 

 which enables the farmer to keep a larger farm stock, by 

 which the quantity of manures are increased. Manure is the 

 great source of fertility. In proportion, therefore, as root 

 culture is made a part of a rotation system, we should ex- 

 pect the soils to increase in fertility. 



CHAPTER VII. 



IMPROVEMENT OF THE SOIL BY MANURES AND TILLAGE. 



The improvement of the soil by manures surpasses all 

 other methods. This subject is one that comes more di- 



