18 



Most remarkable was the continuous cultivation of wheat on the 

 same land on the farm of the University at Columbus. The crop 

 was also totally destroyed in 1896, but in 1897 the land, which had 

 been sown with wheat for nine years in succession, without having 

 received any fertiliser, yielded 39 bushels of wheat per acre. This 

 hows how favorable a season 1897 was. The clay land at the Ohio 

 Station reached also 40 and more bushels per acre. As regards the 

 fertilisers used phosphoric acid has given more than twice as great 

 a. value of total increase as that obtained from either potash or nitro- 

 gen and a 50 per cent, greater increase than that obtained 

 rVom potash and nitrogeii combined, although the 

 phosphoric acid had been used in smaller quantity 

 than either potash or nitrogen. Potash added to phos- 

 phoric acid showed about an increase equal to the sum of that 

 obtained from the two used separately ; but the increase was much 

 greater from phosphoric acid and nitrogen combined than that from 

 these two used separately. With potash added to the last combination, 

 we have a complete manure, and an aggregate increase more than 

 tvv'o and a half times as great as that produced by the phosphoric 

 acid used alone. Phosphoric acid, potash, and nitrogen, all three- 

 produced the greatest increase of crop. The Director of the Ohio 

 Station then states that for wheat the proportion of nitrogen may 

 ^closely approximate that of phosphoric acid, and he recommends 

 slaughter-house tankage, although a less effective carrier of nitrogen 

 than nitrate of soda. He thinks it the most economical source of 

 nitrogen when due allowance is made for the phosphoric acid carried 

 by the tankage. At all events, the large quantities of nitrate of 

 soda (from 5 to 7 cwt.), used with either superphosphate or Thomas 

 phosphate and muriate of potash, swallowed the whole of the good 

 cr'vp. With tankage a good profit was made. 



Director Buhl, of Lorraine, had a similar result with nitrate 

 of soda, combined with either potassic or phosphatic manures, unless 

 Le used all three fertilisers in the proportion of only 256 Ib. of nitrate 

 of soda, with 480 Ib. of Thomas phosphate and 108 Ib. of muriate 

 of pota-sh, when his crop of wheat sold for 4/6/5, and the manure 

 -costing 2/3/5 ; the profit was 2/3/ per acre. 



Professor Wagner also made a number of experiments with wheat 

 ir. pots containing 36 Ib. of soil to verify resiilts obtained in the fields 

 of the late lamented Schultz-Lupitz, and plates explain themselves 

 sufncientlv, viz., that wheat requires also potash, besides a full 

 supply of phosphoric acid and nitrogen/. 



Experiments in Germany on a mild loam in good heart by Mr. 

 Leesch, of Wolgast: 



^Vithout manure 25 cwt.'grain, 34 cwt. straw per acre. 



With 3 cwt. kainit, ") 



3 cwt. Thomas phosphate, 1 30-20 " " 42-20" " " 

 3 cwt. nitrate of soda, " Profit, 17 2. 



8 cwt. lime, 



The nitrate was given on 15th May (here perhaps September) 

 the others before winter. 



