576 EXPERIMENT STATION RECORD. 



(1 gm. and 0.5 gin. of the latter iu case of the white sulphate and 0.5 

 gm. in case of the brown sulphate). 



"[The results show that] -without lime the yield where the brown ammouium sul- 

 phate was used was practically the same as from the white lot, so that if any ill 

 effect had resulted from the use of the white product it is obvious that the ill effect 

 from the brown lot was no greater. In fact no positive ill effect was noticed in 

 either case. Comparing the two kinds again, where lime was used with each the 

 results were practically the same, for we have 31.2 gm. from the white ammonium 

 sulphate aud 30.4 and 31.6 gm. from the brown, so that whether used with or with- 

 out lime it gave results fully equal to the product which w;is free from ammonium 

 thiocyanate. Where ammonium thiocyanate was used in connection with the brown 

 ammonium sulphate, even with lime, the yield was seriously affected. The same 

 was likewise true where the thiocyanate was applied iu connection with the white 

 ammonium sulphate and lime, and where the larger quantity was applied . . . 

 the weight of oats was but 7.6 gm. In view of the fact that the growth was 

 excellent except where ammonium thiocyanate was added, and in consideration 

 of the fact that ammonium sulphate has always worked well upon this soil after 

 liming, the poisonous action of ammonium thiocyanate upon plants is again 

 demonstrated." 



Field experiments with fertilizers, 0. E. Thorne, J. F. Hickman, 

 and W. J. Green {Ohio Sta. Bid. 71^ pp. 109-1G4). — A preliminary dis- 

 cussion is given of the amount of fertility removed from the soil by 

 average crops of corn, oats, wheat, clover, and timothy grown in a 

 5-years' rotation ; the quantity and cost of fertilizers used in the State 

 iu 1894, and the most economical means of restoring the fertility 

 removed in crops. 



"To return the fertility removed by the average crops of the rotation under con- 

 sideration would require : 



1,157 pounds nitrate of soda, costing $26.00 



354 pounds dissolved bone black, costing 3.20 



272 pounds muriate of potash, costing 6.80 



Total cost 36.00 



"It will be observed that there is a wide margin between the cost of these mate- 

 rials and that of the ordinary mixed fertilizers as sold in Ohio, but even this cost 

 would consume the greater part of the value of the crops produced if it were neces- 

 sary to return to the soil all the nitrogen, phosphoric acid, and potash which the 

 crops carry away. ... 



" However, no one believes that it is necessary to return to the soil all the nitrogen 

 which the crops have carried away, however it may be with regard to the phosphoric 

 acid and potash." 



The experiments of the station were undertaken to determine (1) 

 whether one of the essential constituents may be economically omitted 

 from a fertilizer mixture, (2) the most economical proportion of these 

 ingredients, (3) to what extent the use of nitrogen may be reduced by 

 growing clover, (4) the relative powers of different crops to secure their 

 own supplies of plant food, (5) what proportion of the fertilizing con- 

 stituents applied to the soil is recovered in the crop, and (6) the best 

 forms of the fertilizing constituents. Following is the general plan: 



"Nitrogen, phosphoric acid, and potash, as carried in nitrate of soda, dissolved 

 boneblack, and muriate of potash, are applied singly, by twos, and all three 



