SOIL MANAGEMENT FERTILIZATION OF ORCHARDS 



43 



Many experiments have shown that abundant nitrogen favors the set of 

 fruit. There is also no doubt that on these plots the fruit has been larger 

 than on the unfertilized plot. These additional factors would contribute 

 to the increased yield of the trees on the four fertilized plots. Inasmuch 

 as the trees on the unfertilized plot now approach those of the other plots 

 in size, it is probable that this inferiority would be somewhat less marked 

 in the future were the treatment to be continued as in the past. 



Fig. 5. — Yields by plots in percentages of total yields of the whole orchard. Plots 1, 

 and 3. 



It was observed that the ashes, muriate and sulfate plots produced con- 

 siderable growth of clover while fertilizer applications were kept up. 

 When these ceased in 1916 the clover gradually disappeared. Xo doubt 

 this growth of clover contributed nitrogen to the trees. The decline in 

 growth and production of these three plots during the last four or five 

 years may have been in some measure due to this lessened nitrogen supply. 



The relative yields of the five plots are shown from another viewpoint 

 in Figs. 5 and 6, where the yields are shown in percentages of the total 

 crop of the whole orchard. Fig. 5 shows plots 1, 2 and 3, and Fig. G shows 

 plots 4 and 5. Here, again, the heavy lines show the on-year yields and 

 the light lines the off-year yields. Inasmuch as there are five plots, the 



