52 



MASS. EXPERIMENT STATION BULLETIN 196. 



Table IX. — Percentage Results. 



The general percentage average for plots 1, 2, 4 and 5 for the entire 

 period 1912-19, inclusive, N being taken as 100, is 122.3 for S, while for 

 plot 3 a similar comparison shows the standing of S to be 138.2. 



The figures presented in the different tables bring out the fact very 

 clearly that the lasting effect of manure piled when taken to the field and 

 spread in the spring is much greater than that of manure spread in the 

 winter. For confirmation of the fact just stated, the reader should com- 

 pare the figures given in Table IX with those in Tables VI and VII, 

 which refer to the period during which manure was applied annually. 



The figures for successive years presented in Tables VIII and IX in- 

 dicate clearly that the superiority of plots S as compared with plots N 

 as yet shows no signs of diminution. On the contrary, it is considerably 

 greater during the later years of the period under consideration than in 

 the earlier. This is most clearly sho'UTi in the last column of Table IX, 

 which gives the percentage averages of the five plots; thus, for example, 

 during the first and second years of the period under consideration, plots 

 S in mixed grass and clover showed a percentage superiority of 111.0 

 and 104.6; in the last two years, 1918 and 1919, corresponding figures 

 were 115.9 and 151.8. A similar relation is shown between the percentage 

 advantage of plots S in 1915 as compared with 1914, soy beans being the 

 crop; and in 1917 as compared with 1916, corn being the crop. This 

 advantage in the case of the corn crop is less than with the others. 



