Ecology, Environment and Conservation Paper

COMPARISON OF EFFECT OF ZINC-ENRICHED POD OF PHASEOLUS VULGARIS AND INNER RICE HUSK COMPOSTS WITH ZINC SULFATE AND ZINC 14% CHELATE ON ZINC AVAILABILITY IN MAIZE PLANT IN A CALCAREOUS SOIL

Shabnam Rasouli. Pirouz Azizi, Akbar Forghani and Ahmad Asghar Zade

Abstract

Mixtures of Zn salts and organic matter- uch as manure, compost, and various organic industrial byproducts - have been used successfully in controlling zinc deficiency in various crops. The aim of the present study was to optimize the effectiveness, on zinc availability in maize, of natural organic substances by enriching them with zinc sulfate. For this purpose, pod of phaseolus vulgaris and inner rice husk, as abundant organic wastes in the north of Iran, were incubated with increasing quantities of zinc sulfate. The effect of these zinc-enriched composts, zinc sulfate, and zinc 14% chelate on zinc availability in maize in a calcareous soil was studied in a greenhouse experiment. DTPA-extractable zinc of the soil, total zinc concentration, and chlorophyll of plant leaves were measured. Soil applications of all treatments, especially zinc-enriched composts, increased DTPA-extractable zinc more than the control treatment, but this increase is not significant for zinc chelate. The plant analysis indicated that zinc-enriched composts of both organic matters significantly increased total zinc concentration in plant leaves more than the control treatment, and their effects increased by increasing the level of enrichment until toxic level, even over that.of zinc chelate. Non-enriched of both organic matters and zinc chelate had the most effect on leaf chlorophyll and significantly increased the amount of chlorophyll more than the control treatment.