208 VEGETABLE GROWING PROJECTS 



it is dry enough to work. Not a day nor an hour should be lost 

 in harrowing, in order that the escape of moisture from surface 

 evaporation may be reduced to a minimum. A fine soil mulch 

 should be maintained by harrowing until the potatoes are planted, 

 and then weeders and cultivators should be used for the same 

 purpose. 



There is a very great difference in practices relative to the use of 

 commercial fertilizers for potatoes. The growers of early potatoes 

 on light sandy soils used an immense quantity of high-grade 

 complete fertilizer before the World War. It was not uncommon 

 to apply a ton of fertilizer to the acre, which contained 4 to 6 per 

 cent of nitrogen and 8 to 10 per cent of each of the mineral 

 elements. 



When a clover sod or other leguminous crop is plowed down for 

 late potatoes it is unnecessary to use as much nitrogen as for the 

 early crop, especially in light soils. Under most conditions in the 

 North, it is likely that 2 or 3 per cent of available nitrogen in a 

 1000 pound application to the acre will furnish as much nitrogen, 

 in addition to the nitrogen of the legume plowed down, as will be 

 required to secure a satisfactory growth of plants. It is admitted 

 by most growers that liberal amounts of the mineral elements are 

 essential, though very large crops were grown during the war 

 without applications of potash. Ordinarily, about 150 pounds of 

 nitrate of soda, 500 pounds of 16% acid phosphate, and 300 pounds 

 of muriate of potash, used as a supplement to stable manure, or 

 after a clover sod is plowed down, will give good results, if other 

 conditions are favorable. The fertilizer, however, should not be 

 applied until spring, when the land is harrowed. If the plowing 

 is not done in the fall, it should have the earliest attention in the 

 spring. 



Inasmuch as fresh lime encourages the development of scab on 

 potatoes, the liming should be done in connection with other crops, 

 preferably the cereal which precedes the clover. 



