256 CROP GROWING AND CROP FEEDING 



MANURING FOR THE SWEET POTATO CROP. 



There is no doubt that the organic matter needed by the sweet potato 

 could be more cheaply grown on the land by a crop of legumes than by the 

 laborious raking up and hauling and spreading of the forest mold, and it 

 is hoped that the growers will soon find out this fact. There need be no 

 fear that there will be an excess of nitrogen, provided it is balanced by a 

 liberal application of phosphoric acid and potash. It is not the amount of 

 nitrogen that is harmful but the excess in proportion to the other constituents, 

 and a very rank growth of vines may produce a fine crop of roots if the food 

 is at hand which is needed for the storing of starch and sugar. It is the 

 unbalanced ration in the soil that does the harm and not the amount of plant 

 food present. We have explained that in discussing the garden culture of the 

 Irish potato in which similar conditions exist. The rotation of crops and the 

 growing of legumes is just as important to the vegetable grower as to the 

 farmer, and in no way can he so economically stock his soil with the needed 

 humus as by the growing of legumes between sale crops. 



But no matter whether we haul the rotten leaves from the forest or get 

 the vegetable decay from a crop of pea vines, the getting of it in the soil in 

 abundance is an important matter to the success of the sweet potato crop. 

 Having this organic matter then there will be no need for the application of 

 any nitrogenous fertilizer whatever, except in Northern localities where the 

 short season requires that the crop be hurried. In such cases the top dressing 

 along the rows of nitrate of soda at rate of 25 pounds per acre at two applica- 

 tions, will be the best. The general mixture for use in the Middle and South- 

 ern States will then be: Acid phosphate, 1,600 pounds; sulphate of potash 

 (high grade), 400 pounds. Five hundred pounds per acre of this mixture 

 will be an abundant dressing for the sweet potato crop. 



GROWING THE PLANTS. 



Sweet potatoes are always grown from plants sprouted in the spring 

 from roots kept over for this purpose. That is, these plants are always used 

 for the first planting in the South and for the entire planting in the North. 

 The late crop in the South is produced from cuttings of the vines of the early 

 planted crop. In the North it is the common practice to bed the potatoes 

 in a hotbed under glass, and in the potato growing section of the Middle 

 States fire-heated beds are often used. In the South the bedding is general- 

 ly done in the open ground with a cover of straw to assist in keeping out cold. 

 As the plants cannot be set in the open ground till it is settled and warm, 



