Availability of soil moisture, particularly as affected by depth, in the soil of the Kentucky Experiment Station Farm at Lexington
1939
Karraker, P.E. | Bortner, C.E.
Data are reported of the moisture in different layers of Maury silt loam soil on the Kentucky Experiment Station farm in variously cropped and uncropped land in the dry years of 1930 and 1936. Below 4 or 5 feet the soil contained approximately its maximum field capacity. Above this, moisture decreased towards the surface but below 2 to 3 feet no faster in the cropped than the uncropped areas. Above 2 to 3 feet the decrease was considerably greater in the cropped than in the uncropped areas. This indicates that the crops obtained water chiefly from the top 2 to 3 feet. Observations of depth of root penetration showed that the crops did not root effectively below this depth. In pot experiments, 12% of water in the surface soil and 23 to 24% in the subsoil was unavailable to corn plants so that even if crops rooted extensively in under soil layers, the amount of water obtained here would not be great.
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