ISSN:
1573-5036
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary Fe-EDTA and Fe-HEEDTA, labelled with Fe59, were applied at rates of 10 and 100 ppm iron to 50-g samples of dry soil, which were then stored for periods ranging from one to fifteen days before extracting with water. The analyses of the extracts lead to the following general conclusions. 1. The decrease in soluble iron could be attributed to both sorption of chelate anions by the clay and to replacement of iron by calcium in the chelate molecule. 2. The amount of each chelate sorbed changed little with time and was proportional to the quantity applied. More HEEDTA was sorbed than EDTA. 3. The initial decrease in the concentration of soluble iron was rapid for both chelates, but was the greater for Fe-HEEDTA. 4. The precipitation of iron from the soluble Fe-HEEDTA was slower than from Fe-EDTA, so that fifteen days after treatment more soluble iron was obtained from the Fe-HEEDTA treatments. 5. Marked increases in the recoveries of Fe-EDTA were made when the treated soils were sealed within small containers, compared with those allowed free access to the air. Comparable treatments using Fe-HEEDTA had a much smaller effect. 6. Isotopic exchange of Fe59 with natural soil iron was greater in the treatments with 10 ppm chelated iron than the 100 ppm level. Fe-HEEDTA was subject to more exchange than Fe-EDTA at both levels. These results are discussed in relation to the treatment of soils with iron chelates for the control of lime-induced chlorosis, and to the importance of isotopic exchange when using chelates labelled with radioactive iron in soil.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01666161
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