The feasibility of using electro-osmosis for removal of heavy metals (Cd, Cu, and Pb)

The objective of this study was to evaluate the distribution of cotton (Gossypium hirsutum cv GSA 71) root system under four depths of trickle irrigation emitter. Cotton was grown on an Amarillo fine sandy loam (fine loamy, mixed thermic Aridic Paleustalf) at Lubbock, Texas. Trickle irrigation was applied at the surface (0), 0.15, 0.3, or 0.45 m depths in amounts calculated using daily pan evaporation, crop coefficient, and crop development stage. Effects of depth of trickle irrigation were evaluated by measuring the cotton root-length density in 0.15 m increments to the 0.90 m depth at distances of 0, 0.25, and 0.5 m perpendicular to the cotton rows. The root-length distributions were not significantly (0.05 %) different in the top 0.15 m when the surface irrigated treatment was compared with the 0.45 m irrigation depth treatment. Root-length densities for the 0.15 and 0.3 m treatments were not significantly different from one another nor were they different from treatments within the evaluated zones (0 to 0.3 m or 0.15 to 0.45 m). Root-length density within the 0.3 to 0.6 m zone, was not significantly different for the 0.45 m treatment compared with the surface irrigation treatment. Root-length density in the 0.6 to 0.9 m zone was not significantly different for any treatment. Emitter depth of trickle irrigation did not significantly influence the depth or distribution of cottonroot development.Knowledge of root-length distribution as a function of depth and lateral distance from the plant is essential to development of models used in irrigation management. However, little information is available on rooting patterns of cotton under trickle-irrigated conditions. Rooting distribution of field-grown cotton has been documented (Weaver 1926;Bruner 1932;Long 1959) and McMichael (1986) described the development of the cotton-root system. Klepper et al. (1973) discussed the interrelationship between soil-water status and cotton root-

No abstract

No abstract