SUBSOIL A FACTOR IN GROWTH OF APPLE TREES 7 



orchards in which the area is less than 5 acres. Three hundred 

 orchards, more than one-half of which belonged to the commercial 

 class, were counted. The average size of the orchards was about 30 

 acres. 



The objection may be offered to these data that the stand of an 

 apple orchard depends as much on the care which has been given it 

 as on the soil on which it is planted. This is true, especially of 

 orchards in the earlier stages of development. In the area studied 

 there are good orchards which show a high percentage stand on 

 soils of both groups and on each of the four principal soils consid- 

 ered. Some of the better orchards are on soils which are not most 

 desirable for orchard planting, such as Gerald soil in which the clay 

 layer is not highly developed or Lebanon soil where the hardpan has 

 a cleep soil covering. This is undoubtedly in a large measure due to 

 good care and skillful handling. A poor stand may be due to disease, 

 gnawing of rabbits, fire, or other causes, but a check of stand in a 

 large number of orchards would determine if the subsoil is an im- 

 portant basic cause in determining the length of life and stand of 

 trees. 



The most striking fact brought out in this count is that the percent- 

 age stand in the area as a whole is low. Orchards seen from a dis- 

 tance or from the highway may seem to have a perfect stand, but on 

 actual count many trees are found to be missing. The next most 

 noticeable fact is that the percentage stand is lower in the small 

 orchards than in the larger ones, due to the better attention given the 

 larger orchards. Counts in the small orchards, however, gave much 

 valuable information. In these the influence of soil conditions is 

 more manifest than in orchards receiving better attention, and in 

 most of them variation in stand can be traced directly to subsoil 

 conditions. 



The most striking variations in stand are on the Lebanon and Bax- 

 ter soils. On Lebanon soils on top of ridges, where a highly de- 

 veloped hardpan lies near the surface, the stand is almost invariably 

 poorest. Poor stands are frequently found on small areas of Baxter 

 soils where the soil is very rocky or where underlying, unbroken 

 chert beds are near the surface. In orchards planted partly on Bax- 

 ter and partly on Lebanon soils the stand is better on the slopes 

 where the Baxter soil occurs than on top of the divides or on flat 

 areas which consist of Lebanon soil. In the Gerald soils the stands 

 are usually poorest where the surface is extremely flat and drainage 

 is poor. On the Xewtonia soils there is much greater uniformity of 

 stand than on the other soils. The subsoil conditions are the prin- 

 cipal cause of lack of uniformity in stand. 



Summarizing the results of these counts, the stand of orchards 

 counted on different soils is as follows : Gerald soils, 70 per cent ; 

 Lebanon soils, 71 per cent; Baxter soils, 79 per cent; and Newtonia 

 soils, 81 per cent. Soils having tight subsoils have 70.5 per cent of 

 stand, whereas those having open subsoils have 80 per cent. 



The size and appearance of the trees on soils having open subsoils, 

 as compared with those on soils having tight subsoils, are even more 

 striking than the difference in stand. Even in orchards which have 

 received good care there is a close relation between the size of trees, 

 diameter of trunk, and normal limb spread and subsoil conditions. 



