Calcium Sulphate. 



The following comparison between the amounts of the essentials 

 furnished by the fertilizers used and the amounts found in fifty bush- 

 els of corn and its usual proportion of stover and cobs is of interest : 

 Furnished pounds. Required 'pounds. 



Nitrogen, 25.12 91 



Phosphoric acid, 48.19 29 



Potash, 81.55 63 



It will be noticed that nitrogen is applied in far less amount than 

 the crop requires, while phosphoric acid is applied in large and 

 potash in moderate excess of the requirements of the crop. 



The manures used in the several experiments varied widely ; but 

 all supplied far more nitrogen than the fertilizers, while the potash 

 was in a number of cases much less. Herein, perhaps, lies, at least 

 in part, the explanation of the fact that of the different elements of 

 plant food potash seems to be more often proportionally deficient in 

 soils than either phosphoric acid or nitrogen. 



In all cases fertilizers and manures were evenly spread broadcast 

 upon the ploughed land and harrowed in just previous to planting 

 the seed. 



The selection of seed was left to the individual experimenters, as 

 it was felt that success would be more certain with varieties suited 

 to the several localities and familiar to the cultivators. In most cases 

 a variety of yellow flint corn was selected. The rows were in all cases 

 three and a-half feet apart and hill planting was generally adopted. 



Each experimenter was furnished with a standard maximum and 

 minimum thermometer and a rain guage ; and, although accidental 

 breakages of instruments caused some irregulaiities, observations 

 were generallj' kept up from the time of planting to the time of 

 harvest. A summary of the record of each observer will be found 

 under the account of his experiment. 



Each experiment was visited twice either by myself or by my 

 assistant, Mr. F. 0. Williams, and the latter gentleman assisted in 

 the harvest, weighed the crops on the several plots and took a sample 

 from each in every experiment. 



