67 



a complete manure, containing nitrogen, potash, and phosphoric 

 acid gave 7 tons 3 cwt. 32 Ib. per acre ; without phosphoric acid, 

 4 tons 19 cwt. 40 Ib. ; without nitrogen, 4 tons 9 cwt. 24 Ib. ; and 

 without potash, 3 tons 1 cwt. 56 Ib. Experiments conducted m 

 Cumberland by C. D. Hunter, F.C.S., with complete manure, con- 

 taining nitrogen, phosphoric acid, and potash gave 9 tons 2 cwt. and 

 8 tons 3 cwt. : without potash, 5 tons 7 cwt, and 4 tons 10 cwt. ; 

 without manure, 4 tons 14 cwt. and 3 tons 4 cwt. Dr. Aitken finds 

 that 2J cwt. per acre of refined potash salts with other manure* 

 give best results. Professor Dr. P. Wagner says to produce 400 cwt. 

 per acre potatoes require 80 Ib. of phosphoric acid, and in an 

 article on the necessity to supply nitrogen to the land, gives us the 

 results of four experiments with potatoes grown in a sandy soil 

 at Arheilgen. While respectively 156 cwt., 128 cwt., 100 cwt. 40 Ib., 

 and 167 cwt, 20 Ib. per acre were obtained without manure, against 

 186 cwt., 242 cwt., 197 cwt. 60 Ib., and 229 cwt. 60 Ib. with potash, 

 phosphoric acid and 4 cwt. of nitrate of soda, when omitting the 

 nitrate of soda the first plot gave no increase over the unmanured 

 plot, the others respectively 69 cwt. 20 Ib., 49 cwt. 20 Ib., and 18 

 cwt. 40 Ib. per acre. 



From twenty experiments made in Southern Pines, N. Carolina, 

 U.S., the following conclusions are formed, that aoa increase of 

 potash showed a gain in the percentage of first-grade potatoes by 

 12 per cent, when double the normal ration was given. Increasing 

 the phosphoric acid to double normal ration increased the first- 

 grade potatoes by only 3 per cent., and where the nitrogen was 

 so increased the first-grade potatoes were 4 per cent, ahead. But 

 both phosphoric acid and nitrogen promoted the total yield of 

 tubers by 8 per cent, of all sizes. Two plots unmanured of one- 

 twentieth of an acre, yielded 86.4 and 98.7 Ib. of potatoes, while 

 250 Ib. of nitrate of soda, 400 Ib. of acid phosphate, and 160 Ib. 

 of muriate of potash yielded 239.4 Ib., and with an addition of 2,000 

 Ib. lime, 306.7 Ib. tubers. French experiments generally show the 

 importance of nitrate of soda, even where large quantities of farm- 

 yard dung were given, except where M. Monville had at Bellevaux 

 planted Magnum Bonum in very good soil, rich in humus. He 

 had three plots of 150 ft. square, giving to No. 1, 4 Ib. of Thomas 

 phosphate and 2 Ib. of sulphate of potash ; to No. 2, 4 Ib. of 

 Thomas phosphate, 2 Ib. of muriate of potash, and 2 Ib. of nitrate 

 of soda; and to No. 3, no manure. The crop was alike in No. 1 

 and 2 of more than double the quantity of finer tubers than taken 

 .from No. 3. 



M. Le Henry's, of Ferre, experiments resulted from no manure 

 in 9,600 Ib. of tubers; No. 2, with farmyard dung, in 11,200 Ib. ; 

 No. 3, with farmyard dung and 480 Ib. of Thomas phosphate, in 

 24,000 Ib. ; No. 4, with the same as No. 3 and 80 Ib. nitrate of soda, 

 in 26,720 Ib. ; No. 5, with the same as No. 4 and 160 Ib. of sulphate 

 of potash, in 28,800 Ib. per acre. 



M. Gallien, of Leotoing, had nearly one-third more tubers when 



he added 800 Ib. of Thomas phosphate to farmyard dung, and netted 



6/14/6 per acre. M. Kunsch, of Montfaucon, planted "Magnum 



