Field experiments on rice (Oryza sativa L.) during two rabi seasons were conducted in an Aeric Haplaquept (pH, 6.7; organic carbon, 0.54%; CEC, 14.28 cmol (p⁺) kg^-1; DTPA-extractable Zn, 0.32 mg kg^-1). The amount of Zn content in rice plant was determined with the help of an Atomic Absorption Spectrophotometer (Perkin elmer, model- AAnalyst 100) after acid digestion of the samples. The results show that the amount of Zn content in and uptake by grain (17.6 mg kg^-1 and 85.6 g ha^-1) and straw (17.0 mg kg^-1 and 123.4 g ha^-1) have been found to be increased significantly in the treatment F3 where twice foliar applications of Zn as Zn-EDTA @ 0.05% was made with the simultaneous highest increase in grain (4.9 t ha^-1 ) and straw (7.2 t ha^-1) respectively, as compared to foliar applications of same levels of Zn as ZnSO₄being 16.0 and 38.8 percent increase in the yield of grain and straw respectively over that of the control, no application of Zn. The results also clearly indicated that the yield of both grain and straw due to foliar application of Zn either in the form of Zn-EDTA or ZnSO₄ were significantly positively correlated with the Zn uptake by grain and straw, being more significant with Zn-EDTA application. The grain yield vs. Zn content in grain showed a significant positive correlation (r=0.82**) suggesting an important role of Zn towards contributing the yield of rice.

Key words: Lowland soil conditions, yield of rice, sources of Zn