Tillage, Fertilizing and Rotation 111 



10 to 15 wagon-loads to the acre. It may be applied 

 broadcast, and harrowed into the soil, or drilled into the 

 rows before bedding. 



Peat, muck and leaf-mold. — Clay soils and others 

 having a tendency to compactness and those deficient in 

 organic matter can often be improved for the growth of 

 sweet potatoes by an application of peat, muck, or leaf- 

 mold. Sometimes these substitutes contain as high as 

 4 per cent nitrogen. Their chief value, however, is in 

 the humus which they contain. The distance which 

 such substitutes have to be hauled will determine the 

 advisability of use. 



Poultry manure. — The value of poultry manure is 

 too often unappreciated by farmers. This substance is 

 rich in nitrogen and phosphoric acid. It is valuable as 

 a fertilizer for sweets in the North where they are 

 grown as a garden vegetable. If the full utility of this 

 fertilizer is received, care must be taken of it, as a 

 large part of the nitrogen may be lost by evaporation. 

 Poultry manure, or any other barnyard manures should 

 never be mixed with ashes since they contain alkalies 

 which increase fermentation, causing a loss of nitrogen. 



Hardwood ashes may be applied to sweet potato land 

 at the rate of 1200 to 2000 pounds to the acre. A 

 good grade of wood-ashes should analyze from 6 per cent 

 to 8 per cent of available potash. They also contain 

 considerable lime. The food value may be reduced by 

 excessive leaching. 



Lvme is also applied to sweet potato land when a large 

 amount of green material has been turned under for 

 organic matter. This neutralizes the sourness that 

 often is caused by the green crop. From one to two 

 tons may be applied to the acre. Lime present in the 



