PLACE FOR MANURE 383 



when plowed under. Composting, or plowing under after 

 it has been applied to sod for several months, or incorpo- 

 rating with a green manure, are methods that must be 

 used with "dry farming." 



Even on heavy soils in a humid region, there is an 

 advantage in applying small dressings of farm manure 

 frequently, rather than large amounts at long intervals. 

 Organic matter decomposes more rapidly when present 

 in the soil in relatively small amounts, and its influence 

 on the solubility of plant nutrients is therefore greater 

 in proportion to the amount of manure used. There can 

 be no doubt that the bacterial flora introduced into the 

 soil by the incorporation of farm manure is an important 

 factor in its usefulness, and when this occurs at frequent 

 intervals it has a marked effect on productiveness. 

 Applications of ten tons to the acre are better than 

 twenty tons at twice the interval. 



252. Place in crop rotation. When a crop rotation 

 includes grass or clover as one of the courses, the appli- 

 cation of farm manure may well be made at that time 

 as a top-dressing. The spreading can be done at times 

 when cultivated land would not be accessible, and the 

 crop of hay will profit greatly. The sod, when plowed, 

 is frequently planted to corn a crop that is rarely 

 injured by farm manure. On light, dry soils this practice 

 is of advantage, as already explained. 



Most cultivated crops, with the exception of tobacco, 

 and occasionally sugar-beets, are much benefited by 

 farm manure. Small grains are usually benefited when 

 grown on poor, heavy soils with plenty of rainfall; but 

 in a dry region farm manure should not be applied 



