FARM CROPS. 179 



fresh manure or sod diminish the moisture supply and 

 are apt to favor the production of scabby potatoes. 

 Potatoes may follow corn which has been heavily fer- 

 tilized with green or farm manure. 



Fertilizers. Irish potatoes are an exhaustive crop 

 from the fertilizer standpoint, but from the money 

 value viewpoint they are less exhaustive than the small 

 grains. They are grown as an early and a late crop 

 in the North, and in the South they are generally most 

 profitable when harvested in early spring. The 

 early crops are forced with heavy fertilization, while 

 the late crops are allowed to grow slowly and with less 

 fertilizer. Potash as sulphate seems to be best, as 

 it produces more uniform potatoes which stand stor- 

 age better than when fertilized with potash in the form 

 of chloride. For early potatoes 800 to 2,000 pounds 

 per acre of a fertilizer containing plant food in avail- 

 able forms, carrying 3 to 4 per cent, of nitrogen, 6 to 

 8 per cent, of available phosphoric acid, and 8 to 10 

 per cent, of potash as sulphate is recommended. For 

 late potatoes 600 to 1,200 pounds of a fertilizer con- 

 taining 2.5 to 3 per cent, of nitrogen, 6 to 8 per cent, 

 of available phosphoric acid, and 8 per cent, of potash 

 as sulphate is desirable. It should be understood that 

 these fertilizers supplement barnyard manure or legu- 

 minous green manure. The fertilizers should be ap- 

 plied before the crop is planted, and covered with suffi- 

 cient earth to prevent injuring the tubers. 



Planting. Experiments show that vigorous pota. 

 toes that weigh 4 ounces when cut in half are the 

 best. Scabby and shriveled potatoes should not be 

 used. The tubers should be planted in rows 3 feet 

 apart and 15 inches should be the distance between the 

 plants. The planting may be accomplished with any 

 of the modern potato planters. In level culture the 

 seed pieces may be planted at a depth of 3 to 4 inches, 

 while in ridge culture i to 2 inches is deep enough. 



Cultivation. Potatoes require a large amount of 

 water for successful growth and frequent shallow 



