552 Report of the Department of Horticulture of the 



Plat 1, in sod five and tilled five Carbon Nitrogen 



years 29,400 pounds 2,600 pounds 



Plat 2, tilled ten years 41,800 pounds 3,400 pounds 



Plats 3, 5 and 7 (average of the 



three) in sod ten years 39,400 pounds 3,100 pounds 



Plats 4, 6 and 8 (average of the 



three) tilled five and in sod 



five years 34,300 pounds 3,000 pounds 



One cannot draw positive conclusions from these figures. It is 

 safe to assume, however, since the quantities of carbon and nitrogen 

 are so materially larger in the plat tilled ten years than in any other 

 plats in the orchard, that the tillage and cover-crop treatment has 

 conserved humus and nitrogen rather better than any other treat- 

 ment. In fact, since considerable quantities of nitrogen were added 

 to a part of the trees in sod, thereby increasing the growth of vegeta- 

 tion and adding more nitrogen to the soil than the treated trees 

 have probably taken from it, we are safe in assuming that the tillage 

 and cover-crops of clover are unmistakably more conservative of 

 humus and nitrogen than would the sod-mulch method have been 

 without the application of nitrate of soda. 



The lower carbon and nitrogen content of Plat 1 is probably 

 accounted for by the difference in the soil type between this and 

 other parts of the orchard, as explained in the description of the 

 soil — the plat is in a depression which has more surface wash than 

 other parts of the orchard. Yet, bear in mind that this was the 

 most productive plat the last half of the experiment. 



Comparison of the analyses of the tilled and the sodded soils proves, 

 we again insist, that the miserable condition of the trees in sod can- 

 not be wholly due, in fact can hardly be largely due, to differences 

 in the food constituents in the two soils. Or, if it be a matter of 

 food, the quantities removed from the soil by the apple are so small 

 that they are not appreciable by our rough methods of sampling 

 and analyzing. At any rate we think the statement is warranted 

 from both the soil analyses and the behavior of the trees in this 

 experiment, and from observation in other orchards, that the 

 intensity of the deleterious action of sod is not much influenced by 

 the richness of the soil. 



