Comparison of chelated zinc vs mineral zinc on the yield of rice applied through soil and foliar application

Abstract Zinc is essential for plants, animals and humans. Zinc deficiency persists in our soils which creates problem in many physiological processes of plants. Presently many chelated Zn compounds are available in the market for foliar application with the claim that these compounds perform better than mineral Zn application. To test this claim a field experiment was conducted for three consecutive years (2009-2011) at Soil Chemistry Section, ISCES, Ayub Agricultural Research Institute Faisalabad on a permanent lay out to compare the efficiency of chelated vs. mineral zinc applied through soil and foliar application. The experiment was laid out according to randomized complete block design with three replications. Three levels of mineral Zn viz. 2.5, 5.0 and 7.5 kg/ha were applied at the time of soil preparation. The foliar application of zinc sulphate and cheated Zn was made @ 0.1, 0.2 and 0.3% solutions at transplanting and at 30 days after transplanting. A control was also kept where no Zn fertilizer was applied. Basal dose of NPK was applied @ 150-90-60 kg/ha. The results showed that rice crop significantly respond to Zn application as expected. The three year pooled data revealed that foliar application of mineral Zn and chelated Zn @ 0.3 %gave statistically similar paddy yields (4.67 and 4.50 t/ha, respectively). The plant analysis at panicle initiation stage showed that Zn concentration in plant significantly improved by foliar application of chelated Zn @ 0.3%. Cost benefit ratio showed that foliar application of 0.3% mineral Zn gave maximum return by spending minimum, however the grain yield was also at par with the foliar application of cheated Zn @ 0.3% and soil application of mineral Zn @ 7.5 kg/ha. It is concluded from the study that 0.3% chelated zinc and 0.3% mineral zinc application produced similar yield but the use of chelated zinc is not economically friendly.