41. In the area of the finds, the ground was originally covered by a shallow, loose soil sitting atop a hardpan layer. 42. Iron and aluminium content is high, which causes hardpans , duracrust, or cuirasses to form near the surface due to oxidation. 43. Common salts such as sodium ions contained in wastewater can fulfil this role and lead to a localized hardpan in some soil types. 44. The dandelion is also one of several species which break up hardpan in overly cultivated fields, helping crops grow deeper root systems. 45. Low pH conditions support formation of an iron hardpan , preventing the trees from setting deep roots and preventing internal drainage of soil water. 46. If you're hitting off dirt or hardpan , be sure to put the ball farther back in your stance to assure solid contact. 47. Wind and dust forced Noble and Craig Breedlove's rival Spirit of America team to huddle in their makeshift garages on the hardpan playa. 48. This because a layer of hardpan just below the loam prevented good drainage and kept the plants from getting their roots to the soil below. 49. Deep, poorly drained acidic sandy soils are typical for the area; they have gray topsoil, white subsoil, and a dark hardpan . 50. Cultivator teeth work near the surface, usually for weed control, whereas chisel plow shanks work deep beneath the surface, breaking up hardpan .
