CROPS 145 



The best soil is a deep, warm one, with good drainage and 

 free from acidity, well supplied with potash and nitrogen. 

 Heavy manuring is generally done for this crop, and farmyard 

 manure is especially useful for its water-retaining power in 

 dry seasons, though open to the objection that it favours 

 " scab." On soils rich in lime, superphosphate, potassium sul- 

 phate and sulphate of ammonia are suitable artificial manures, 

 applied before planting, while on soils poor in lime, basic slag 

 should be substituted for the superphosphate and nitrate of 

 soda (ps top-dressing to the growing crop) for the sulphate of 

 ammonia. From 12 to 15 cwt. of "sets " per acre are usually 

 required. In wet districts these are sown in the ridge, in 

 dry ones on the flat. The rows are usually 20 to 30 inches 

 apart, and the " sets " are placed from 12 to 18 inches apart. 

 Potatoes about the size of a hen's egg should be used as "sets"; 

 if larger, they should bo cut, care being taken to leave at least 

 two " eyes " on each piece. The cut surfaces are often dusted 

 with quicklime before planting. 



The fruit of the potato — " apple " or "berry " — is poisonous, 

 as are also, though to a less extent, the leaves or " haulms.V 

 Potatoes consist largely of starch, with very small amounts of 

 protein and ash constituents. The amount of water present is 

 subject to considerable variation — from about 75 to as high as 

 83 per cent. Potatoes are largely used as food for men and 

 animals ; also, especially on the continent of Europe, for the 

 manufacture of alcohol and of fusel oil. 



Average Composition of Potatoes, 



Per cent. 



Water 78-9 



Ash 1-0 



Crude fibre 0-6 



Carbohydrates . , 17 '3 



Protein 21 



Fat • a . . . . . . .0-1 



100-0 



