...(Pig. 3), and if the pan is broken by dynamite or other means, irrigation waters and plant roots will readily work down into the underlying soil mass. In...recements very slowly. In some cases the hardpan is underlain by a compact, semi-cemented layer of soil, sand and gravel that is practically impenetrable...

...cases the material beneath the hardpan is loose soil very similar to that above the hardpan (fig. 6), and if the pan is broken by dynamite or other means,...practically impenetrable to water or to plant roots. (See fig. 7.) With such soils, dynamiting the hardpan is of little or no value as there is no good...

...(Fig. 3), and if the pan is broken by dynamite or other means, irrigation waters and plant roots will readily work down into the underlying soil mass. In...practically impenetrable to water or to plant roots. (See Pig. 4.) With such soils, dynamiting the hardpan is of little or no value as there is no good...