Soils, Fertilizers and Irrigation 155 



Blasting or Tiling. 



In planting:, trees zvheic hardpait is four feet front the surfaee is it 

 necessary to blast the hardpaii, or is there no benefit derived by the bUist- 

 ing? 



If there should be a good available soil under a shallow layer 

 of hardpan, which you say is four feet from the surface, it might 

 be of considerable advantage to bore into the hardpan and explode 

 a dynamite cartridge in it. But if your good soil is really only four 

 feet deep and hardpan continuous below, the blast might cause fis- 

 sures which would prevent standing water in the upper stratum. If 

 you are sure of four feet of good soil above the hardpan you will 

 have no difficulty in growing good trees, if you get the moisture 

 just right and the hardpan slopes in such a way that surplus moist- 

 ure will move away. If, however, you have hardpan at different 

 depths on the tract, so that it may really make basins which will 

 hold water, you are likely to have trouble from accumulations of 

 water which will not only prevent the roots extending to the full 

 depths of the soil, but will also cause some trees to die. Such a 

 danger could be removed by draining the soil to a depth of three 

 and a half or four feet with tile, in order to prevent accumulations 

 at any point. This would be expensive perhaps, but you would be 

 sure that you had rendered your four feet of soil safe and available. 

 If you trust to blasting you will have to wait several years for the 

 trees to tell you whether you helped them or not. 



Effects of Blasting. 



/ have land which is underlaid zvith hardpan tn'o or three feet deep 

 and this in turn is underlaid zvith sand or sandpan. What I would like 

 to know is whether blasti)ig the holes before setting trees zuould alloxv 

 more moisture coming from this sandpan, or, rather, zuhat effect it zcould 

 have as to moisture. 



We do not know. It might make the soil better for the trees 

 by allowing escape for surplus water through previous layers. It 

 might allow the tree to root more deeply for moisture in those strata. 

 It might allow water to rise from such strata if they have water 

 under pressure. It might do other things good or bad, according to 

 conditions prevailing under the hardpan. If you are to irrigate the 

 land the effects would probably be good. 



The Sub-soil Plow. 



/ am contemplating using a sub-soil plozv for the purpose of breaking 

 plozv-sole on grain land. This is about Ayi inches belozv the surface and 

 is about 5 inches thick. This soil is comparatively loose and seems to 

 be of good quality. Do you think that the sub-soil plozv run lozv enough 

 to break this plow-sole will benefit the landf 



There can be no question about the benefit of breaking up this 

 tight stratum, provided you use a long-tooth harrow or a subsoil 



