THE POTATO 79 



of the hay the third year being plowed under ten 

 inches deep in the fall; two years in potatoes, and 

 one year in grain, reseeding to grass with the 

 grain. 



Good crops are raised on both spring and fall 

 plowing, but the latter has several advantages. 

 The ground can be plowed to a greater depth, mak- 

 ing a deeper seed bed and a larger storage capacity 

 for moisture. The weathering through the winter 

 makes fertility available, so that the same soil, if 

 turned up, unweathered, in the spring would con- 

 tain less food in shape to be used by the plant. 

 Fall plowing for potatoes should be deep, at least 

 eight inches, but ten is better. 



Fall plowing in north latitudes or high altitudes 

 makes possible the storage of heat from the sun's 

 rays. Land that has been fall plowed is often 

 eight to ten degrees warmer at planting time than 

 land plowed deep in the spring (thereby turning up 

 a cold subsoil). Fall plowing, in this way, length- 

 ens the growing season, where seasons are short, 

 and often eliminates fungous development that 

 might be damaging to tender potato sprouts. 

 Fall plowing should generally be followed by 

 another plowing in the spring. 



In the Channel Islands the potato land is plowed 

 eighteen inches deep every four years. 



When alfalfa or clover sod is turned under, the 

 plow should be sharp enough to cut the roots; 

 otherwise it is not all killed and the grass may come 

 up later and bother in cultivation. 



If manuring is done, it should be in the fall. 

 Probably the best time to apply manure is to the 

 crop that precedes the potatoes — on the clover or 

 alfalfa sod. In this way there is no possibility of 

 the fermenting or rotting manure making a breed- 



