An Estimate of Certain Chelated, Non-Chelated Zinc Sources and Levels on Zinc Use Efficiency, Availability and Yield of Rice Grown in Texturally Different Soils

This study was planned to estimate the performance of three zinc fertilizers [Zn sulfate heptahydrate (non-chelated), Zn- EDTA and Zn-humate (chelated)] at four levels (0, 2.5, 5.0, and 7.5 mg kg-1) on zinc use efficiency, availability and crop productivity with rice. Field trials were conducted in clay loam and sandy clay loam textured soils using factorial randomized block design (FRBD) with three replications. Data recorded on yield, Zn uptake, DTPA-Zn, Zn uptake efficiency (ZnUPE), Zn utilization efficiency (ZnUTE), Zn use efficiency (ZnUE), fertilizer Zn uptake efficiency (FZnUPE), fertilizer Zn utilization efficiency (FZnUTE) and fertilizer Zn use efficiency (FZnUE). Among sources, Zn- EDTA recorded the highest grain (5307, 5545 kg ha-1) and straw (6691, 6913 kg ha-1) yield, Zn uptake and DTPA-Zn in both soils, respectively. Among Zn levels, invariably of zinc sources the highest grain (5556, 5771 kg ha-1) and straw (7029, 7120 kg ha-1) yield obtained with 5 mg kg-1 Zn, while 7.5 mg kg-1 Zn registered the highest zinc uptake and DTPA- Zn both in clay loam and sandy clay loam soil, respectively. Our results identified that increased Zn levels increased ZnUPE, ZnUTE, and ZnUE. Addition of 2.5 mg kg-1 Zn recorded the highest FZnUPE and FZnUE, while 5.0 mg kg-1 Zn recorded the highest FZnUTE invariably of soil textures. Amongst the sources, Zn humate recorded higher ZnUE and its components. The study concluded that chelated zinc sources performed well than non-chelated (Zn sulphate heptahydrate), and Zn EDTA was more effective than Zn humate in both experimental soils.