SOIL MANAGEMENT FERTILIZATION OF ORCHARDS. 51 



As has been stated, there was a strip across the north ends of the plots 

 that remained in sod during the entire experimental period. The trees 

 on this strip made considerabI.y less growth than those in cultivation, as 

 shown in Table 2. 



Table 2. — Average Increase in Trunk Circumference, 1908-17. 



The trees on plot 7 made relatively more growth in sod than those on 

 the other fertilized plots, but owing to the small number of trees involved 

 there is a question if the difference is significant. With this one exception 

 the two series of plots parallel each other very closely. The parallel be- 

 tween plots 4 and 5 is very close. As previously stated, there was some 

 indication that in the station orchard, under sod or sod mulch conditions, 

 low-grade sulfate of potash was superior to muriate. In this orchard, 

 what slight difference there is is reversed in both the sod and cultivated 

 portions of the plots. 



It has been stated that in 1914 and following years row 2 of each plot 

 received no fertilizer, while row 1 of each plot received only one-half the 

 amounts previously applied. Table 3 shows the average increase in trunk 

 circumference of the trees in cultivation; no dependable comparison can 

 be made of those in sod because of too few trees. 



Table 3. • — Average Trunk Circumference of Trees in Cultivation, All 

 Plots except Check (Inches). 



