ISSN:
1573-5036
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Plastic columns of 11 cm diameter and 35 cm length were uniformly packed to 30 cm depth with two different soils and subjected to percolation with different amounts of simulated precipitation after the addition of ZnSO4 labelled with Zn65 to the surface of each soil column. When drainage stopped, soil columns were frozen and cut into 3-cm segments, and radioactivity was determined with a well-type scintillator. Total Zn was calculated from activity counts. Soil samples were also analysed for exchangeable Zn, Ca, and Mg. Although a greater fraction of zinc was retained by the upper 3 cm of soil, Zn moved to a depth of 12 cm in soil A, and 18 cm in soil B on leaching with water equivalent to 300 mm of precipitation. A similar trend was discernible but with relatively higher concentrations at the lower depths, on leaching with water equivalent to 1200 mm of precipitation. Alternating oxidation and reduction conditions and the presence of Mn had no appreciable effects on the movement of Zn. Exchangeable Zn displayed a pattern similar to that for total Zn. The percentage of the CEC occupied by Zn in the first 3 cm averaged 18 and 7 in soils A and B, respectively and decreased proportionately when half the amount of Zn was replaced by Mn. The concentrations of exchangeable Ca and Mg were lowest in the upper 3 cm, then increased to a depth of 9 cm or more, thereafter becoming nearly uniform throughout the soil columns. It is concluded that movement of Zn through soils depends not only on CEC, but also on additional factors such as water flow-rate, pH, initial Zn content and the migration of other fractions of soils.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02185820
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