GRAIN CROPS. 11 



12. WOOD ASHES AND TOBACCO STEMS AS POTASH FERTILIZ- 

 ERS. 



The above materials are used as fertilizers mainly because the potash, 

 which they contain, makes them valuable. The trouble is, however, 

 that the amount of potash is not a uniform quantity. Thus, wood- 

 ashes that were supposed to contain 5 per cent, of pure potash, are 

 frequently found to have not more than 2 or 3 per cent. This differ- 

 ence in the potash value cannot be detected by the appearance of 

 wood ashes. The potash in tobacco stems ranges from 4 to 9 per 

 cent. It follows, therefore, that the farmer should insist upon a 

 guaranteed chemical analysis in these substances, and should calculate 

 the market price of potash per pound contained in his wood-ashes and 

 like fertilizers before purchasing. 



Jhe following matter treats of the qualities of the three principal 

 fertilizing substances — potash, phosphoric acid and nitrogen — which 

 have been found useful upon many soils, and may be taken as a guide 

 in the fertilization of soils in which the manurial requirements have 

 not been ascertained: 



GRAIN CROPS. 



All the grain crops (wheat, oats, rye and barley) remove from the 

 soil large quantities of nitrogen, phosphoric acid and potash. The 

 experiences of the most successful farmers show that the cereals 

 should have a proper place in the rotation of crops on the farm. Thus, 

 wheat comes in very well after a crop of Indian corn; barley after a 

 well-manured crop of potatoes or Indian corn. 



By green manuring — that is, by '' plowing under" a crop of clover, 

 peas or other plants which draw their nitrogen from the air — the 

 economical farmer is able to obtain sufficient nitrogen to produce a 

 good grain crop, if a liberal supply of potash and phosphoric acid be 

 given to the soil. A light top-dressing of 40 to 50 lbs. per acre of 

 nitrate of soda may be profitably applied to wheat and oats in the 

 spring, even when they follow a nitrogen gathering crop. If grain 

 crops do not follow a nitrogen-gathering crop, a larger quantity of 

 nitrogenous fertilizer is needed; 200 to 300 lbs. of nitrate of soda per 

 acre are suitable quantities, and it is well to apply this in doses, one- 

 fourth (50 lbs.) in autumn at the time of planting, half the remainder 

 (75 lbs.) in the spring, and the balance (75 lbs.) just before the blossoms 

 appear. In spring-planted grain crops, half of the nitrate of soda 

 should be given at the time of sowing, and the rest at the time of stooling. 



