50 MASS. EXPERIMENT STATION BULLETIN 196. 



of plant food remaining in the manure applied during the ^vinter were in 

 many cases at least sufficient to give the maximum yields possible under 

 the other conditions affecting the crop. 



4. I believe that our results indicate that conclusions based upon 

 relative results of the two systems of applying manure compared for a 

 single year or for a short series of years in current farm practice are in 

 many cases unreliable because of the fact that the rate of application has 

 often been sufficient so that even after such losses as occurred the supply 

 of plant food was adequate for the crop under the conditions under which 

 it was grown. 



5. Whether the results of the comparisons made would have been 

 similar on land more nearly level is a question on whicfi I am able simply 

 to express a general opinion. That opinion, based upon extensive oppor- 

 tunities for observation of conditions existing on Massachusetts farms, 

 is that in almost all parts of the State there is sufficient slope to the land 

 under cultivation so that some wash over the surface during winter and 

 consequently some transfer of soluble plant food or absolute waste must 

 usually be expected. 



Relative Lasting Effects of Winter and Spring Applications. 



Manure having been applied annually, with the exception noted, 

 under the two systems compared from 1900 to 1911, inclusive, it was 

 thought best to continue cropping the plots for a series of years without 

 further differing application of either manure or fertilizer to plots N and 

 S. As a matter of fact, the only apphcations made to any of the plots 

 during the period 1912-19, both inclusive, were dressings of lime applied 

 in 1914 and again in 1917 at the rate of 1,866 pounds per acre of calcium 

 and magnesium oxides. Different forms of lime were used on each of 

 the plots 1, 2, 3 and 5, namely, plot 1, hydrated lime, plot 2, marl, plot 

 3, fine-ground limestone, and plot 5, hmoid. In each case both the form 

 and quantity of Ume applied to the two halves of the original plots (N 

 and S) were precisely the same. It would therefore seem that the lime 

 applied cannot have any immediate bearing upon the comparison of the 

 lasting effects of the two systems of appliyang manure previously used. 



The crops grown in the different years now to be considered, and the 

 jdelds on the several plots, are shown in Table VIII. 



It will be noted that the yields on plots S are in general considerably 

 greater than on plots N. The percentage averages for the five plots in 

 the different years, the yields on plots N being taken as 100, are shown 

 in Table IX, also the relative percentage standing of N and S for the 

 several plots. 



