METHODS OF APPLYING MANURE. 



53 



Effect of the Two Systems previously followed in- the Appli- 

 cation OF Manure on Growth during the Early Part of the 

 Season and the Maturing of the Crop. 

 From the very first year of the period under consideration, 1912-19, 

 it was noticed that much earher and more vigorous growth took place 

 on plots S than on plots N. Whatever the crop, the superiority of S was 

 clearly shown by better color and more rapid advancement. It would 

 have been a matter of great difficulty to determine the difference in amount 

 of growth made at any given period by measurement, but the field was 

 under constant careful observation, and my own judgment I feel sure is 

 accurate. When corn was the crop, I should say that by the last of June 

 or the first of July the average height of the plants on plots S was some 

 3 or 4 inches greater than on plots N . When the field was in mixed grass 

 and clover, the degree of superiority was in my judgment about the same, 

 and indicated in inches would, I think, equal about 3 inches by the first of 

 June. The earlier maturity of the crops on plots S also clearly indicates 

 an earlier start and more rapid progress. This is shown most conclu- 

 sively by the figures in Table X, showing the relative proportions of 

 hard and soft corn at the time of husking. 



Table X. — Effect on Ripening Corn (Pounds per Plot). 



It will be noted that plot 5 is an exception to the general rule that the 

 proportion of hard corn is considerably greater on plots S than on plots 

 N. A considerable number of mj^ different experiments, confirmed, I 

 believe, as a rule, by the experiments of others, indicates that the period 

 of ripening is affected more by the supply of phosphoric acid in highly 

 available form than by any other plant-food constituent. An excessive 

 supply of potash or of nitrogen does not, I believe, favor early ripening, 

 but quite the contrary, unless there be a very liberal supply of phosphoric 

 acid. It seems to me highly probable that the relative high standing of 

 plot N on 5 in the proportion of. hard corn is connected with the fact, 

 which is generally known, that the proportion of phosphoric acid in 

 manure from horses is higher, as a rule, than in that from milch cows, 



