RULES OF FERTILITY 39 



2. Frequent surface tillage at times of scanty rainfall, in order to 

 conserve the supply of soil moisture. 



3. A sufficiently rapid rotation of crops to insure good soil texture, 

 to allow the necessary frequency of applying fertilizing material, and 

 as a main result to secure a paying stand of crops. 



4. The introduction into the soil at frequent intervals of an amount 

 of organic matter necessary to proper soil texture and water holding 

 power, either by application of farm manures, by plowing down soiling 

 crops, or by the rotting of the turf. 



5. The scrupulous saving of all the excrement of farm animals, 

 both solid and liquid. 



6. The purchase of plant-food with due reference to the needs of 

 the farm and to the system of farm management prevailing. 



7. The maintenance in the soil of those conditions of drainage and 

 aeration which promote the growth of desirable soil organisms, and the 

 introduction into the soil, when necessary, of such organisms as are 

 essential to the growth of particular plants. 



