248 CROP GROWING AND CROP FEEDING 



The Southern grower of the second crop potatoes for seed to plant the 

 following season will do well to make this selection from the early crop, and 

 not do as many now do, plant only the refuse of the early crop. In the end 

 such a course must finally lead to deterioration. Even now there are growers 

 who say that they find it desirable to return to the Northern seed stock every 

 five or six years. This would be entirely needless if the proper course of 

 selection. was made for the growing of the second crop seed potatoes. 



SOME STATION INVESTIGATIONS IN POTATO CULTURE AND MANURING. 



Bulletin 136 of the New Jersey Station gives the details of experiments 

 with nitrogenous fertilizers on various crops. The experiments with the 

 potato were to determine the relative effect of the three different and distinct 

 forms of nitrogen, as well as the amounts of the same when applied to a light, 

 sand soil, which lacked "condition" and was poor in respect to physical char- 

 acter. It is well understood that the usefulness to the immediate crop of 

 the best forms of the fertilizer constituents is modified by the character of the 

 soil to which it is applied, that larger returns per unit of application may be 

 expected from soils which have been well cultivated and are in good heart or 

 condition than from soils that do not possess these characteristics. The soil 

 was, however, well supplied with phosphoric acid and potash previous to 

 planting the potatoes, the former derived from acid phosphate and bone and 

 the latter from muriate of potash. 



Two experiments were included, each containing ten plats one-twentieth 

 of an acre each, and the table shows the amount of nitrogenous fertilizers 

 applied and the yields per acre of each individual experiment as well as the 

 combined experiments, calculated on the basis of an acre. 



Without giving the detailed table here we will summarize from the bul- 

 letin that none of the plats reached as much as 100 bushels per acre, though 

 the relative increase in yield from the use of the different forms of nitrogen 

 was quite considerable. The forms used were nitrate of soda, cotton seed meal 

 and sulphate of ammonia in various amounts. There seemed to be little 

 difference in the yield from variations in the amount used, the smaller quan- 

 tity having been practically as efficient as the larger. With one exception 

 the nitrate of soda was uniformly more effective than the other forms, the 

 increased yield from the nitrate being on the average 84 per cent. ; from the 

 sulphate of ammonia, 77 per cent., and from cotton seed meal, 38 per cent. 

 The experiment, it is stated, is chiefly valuable in showing that in growing 

 potatoes on such poor soils the first need is for physical improvement, rather 

 than for large doses of the best forms of plant food. That is, they should be 

 made more absorptive and retentive of moisture by the accumulation of 



