FARM MANURES 185 



to use stable manure in excess for trucking, but to 

 supplement it with special fertilizers as the crops may 

 require. Soils which contain a large amount of cal- 

 cium carbonate will not become acid from farm manure, 

 and hence admit of more frequent and heavier applica- 

 tions than soils which are deficient in this compound. 

 The lime aids fermentation and nitrification. Some- 

 times a judicious combination of farm manure and 

 commercial fertilizers can be made that will prove 

 more economical than farm manure alone. 



209. Crops Most Suitable for Manuring. Soils which 

 contain a low stock of fertility admit of manuring for 

 the production of almost any crop. Soils well stocked 

 with plant food, like some of the western prairie soils, 

 which are in need of manure mainly for its physical 

 action, will not allow its direct use on all crops. On 

 a prairie soil of average fertility a heavy application 

 of manure may cause wheat and other grain crops to 

 lodge. When manure cannot be applied directly to 

 a crop, it may be used advantageously on a preced- 

 ing crop and the land thus be brought into good 

 condition for the crop that will not bear direct ma- 

 nuring. Manure never injures corn by causing too 

 rank a growth, and wheat may follow corn which 

 has been manured with but little danger of loss from 

 lodging. 



On some soils stable manure cannot be used for 

 growing sugar beets ; on others it does not seem to exer- 



