104 HATCH EXPERIMENT STATION. [Jan 



Per Cent. 



South Carolina rock phosphate, 100.0 



Phosjihatic slag, 99 . 



Dissolved bone-black, 97.7 



Mona guano, . 95.4 



Florida lihosphate, 64.2 



No-phosphate, 55.4 



The crops which have been raised on the fiekl in the order 

 of their succession are as follows : potatoes, wheat, serra- 

 della, corn, barley, rye, soy beans, Swedish turnips, corn, 

 oats and cabbages. All the plots in the field received an 

 application of lime at the rate of one ton to the acre of quick- 

 lime, slaked, spread after ploughing and deeply worked in 

 with a harrow in the spring of 1898. 



This statement of the conditions of the experiment and of 

 the relative yields on the different plots should perhaps l)e 

 further supplemented by the statement that, supposing the 

 crops harvested to have been of average composition and 

 that there has been no waste, there would remain of the total 

 phosphoric acid applied to the several plots the following 

 amounts in each : — 



Pounds. 



The phosphatic slag plot, 63.6 



Mona guano, 29.7 



Florida phosphate, 132.4 



South Carolina rock phosphate, 102.0 



Dissolved bone-black, 9.5 



The following conclusions appear to be justified by the 

 results which we have obtained : — 



1. It is possible to produce profitable crops of most kinds 

 by liberal use of natural phosphates, and in a long series of 

 years there might be a considerable money saving in depend- 

 ing, at least in part, upon these rather than upon the higher- 

 priced dissolved phosphates. 



2. None of these natural phosphates appear to be suited 

 to crops belonging to the turnip or calibage fiimily ; but 

 whether it is because these crops require the presence of 

 an unusually large amount of solul)lo phosphoric acid, or 

 whether it is because of some other effect of the dissolved 

 phosphates, our experiments do not enable us to say. While 

 we have obtained much the largest crops of turnips and cab- 



