The Effect of Iron-Enriched Vermicompost on Growth and Nutrition of Tomato

Iron deficiency or lime induced chlorosis is a common problem in calcareous soils. Application of mineral iron fertilizer in these soils is not usually fully effective in curing iron deficiency as compared to organic chelates. Cow manure and iron refuse (oxides), a by-product of iron melting factories were mixed in different properties of: 0, 5, 10, and 20 % V/V to make mixtures which of after four months incubation were converted into iron-enriched vermicompost through the action of earthworms. In a greenhouse study, growth and nutrient uptake by tomato grown in pot soils treated with normal vermicompost and Fe-EDDHA (synthetic iron chelate) and compared with those in plants grown in soils receiving iron-enriched vermicompost. The study design was a randomized complete block one with three replications. Total and available forms of iron in iron-enriched vermicomposts as well as in tomato tissues increased by an increase in the proportion of iron refuse in vermicompost. Shoot dry matter of plants produced in soil treated with iron-enriched vermicompost (15-20% V/V), was significantly higher than that of plants produced in the other treatments. Iron uptake by tomatoes grown in Fe-EDDHA treated soil was higher than that in plants grown in vermicompost amended soil and that in control, but it was lower than the uptake by plants grown in iron-enriched growth media.