No. 7. DEiPARTMENT OF AGRICULTURE. p39 



PROF. STEWART: That brings in an entirely different matter. 

 Our work is to find out what is the effect of the various systems of 

 soil management on yield. We find that tillage and cover crop is 

 distinctly best in orchards in which the bearing habit is established. 

 In the side-hill orchard, it would not always be practicable to apply 

 this system, because they would wash, but if you can prevent the 

 washing, I don't see why the effect there would be any different from 

 that in any other orchard. 



PROF. SURFACE: The question has been asked here, to what 

 depth were the orchards cultivated and with what implements, — 

 that is, on old orchards — and for what purpose? 



PROF. STEWART : Three or four inches. The main purpose of 

 tillage, as I see it, is to conserve moisture. A four-inch cultivation 

 will do that as well as a deeper one, and will avoid unnecessary 

 injury to the roots. The implements used were plows, or double- 

 action discs or spading harrows, followed by spring-tooth and smooth- 

 ing harrows. I don't see that there is any objection to any imple- 

 ment that will thoroughly stir up the soil and keep the weeds down. 



PROF. SURFACE :" If it should be a rocky soil, would it be broken 

 up? 



PROF. STEWART : Yes, unless there was too much rock. 



PROF. SURFACE : How late do you till ? 



PROF. STEWART : Up to the 1st of August, this year, although 

 there was very little tillage done in July, there was no need of it 

 either to preserve a mulch or to kill weeds. The reason for this 

 tillage up to August was that we wanted to sow our cover-crop at 

 that time. This was because we thought the chances were better 

 then for enough moisture to get the seed started. And there is 

 plenty of time after that in most Pennsylvania orchards for proper 

 fall growth. ~~ 



PROF. SURFACE : What do you sow for the cover crop? 



PROF. STEWART: A combination of alsike and medium red 

 clover this past year. We have added hairy vetch in some cases, and 

 have used it and rye in others. 



MR. GOOD: I would like to ask the gentleman if cultivation, 

 especially where it is a little bit rocky, so as to bring the roots near 

 the surface, does not injure the roots a few years afterwards? Then, 

 another thing; don't the cover crop in the orchard absorb a great 

 deal of the moisture that the tree should have just at that time — 

 the latter part of the summer? 



PROF. STEWART : I don't now of any injury from cultivation, 

 and as for the demand for moisture, I may again call attention to 

 our results in the Wyoming county orchard this year, where 52 per 

 cent, over the mulch system. 



MR. GOOD : And yet you say that tillage causes the fruit to 

 drop. 



PROF. STEWART: No, the effect seems to be quite the reverse, 

 the figures show this and it is not necessary to argue one way or the 

 other. Now, as to the question as to whether tillage injures the 

 roots of the tree. I suppose that we have some soils that are so 

 shallow that a three-inch tillage would take up all the soil that there 

 is for the apple roots, but orchard soils should be deeper than that 

 if you expect the trees to grow properly. If you have soil of a proper 

 depth, a three-inch tillage will not injure the tree. We have records 

 from over 15,000 acres of bearing orchard in Orleans county, N, Y,, 



