Zinc deficiency in soils and plants is the worldwide problem causing considerable yield reduction and indirectly affects human health due to its lesser concentration in the crop produces grown on zinc deficient soils. Hence to know the effect of zinc supply on the growth, clove yield and Zn accumulation, four field experiments were conducted with varied levels of zinc sulphate (0, 5, 10, 25, 37.5 and 50 kg ha-1) using garlic variety Ooty 1 as test crop on zinc deficient sandy loam soils during the Rabi season of 2018-19. Soils with deficient zinc availability showed better response to different levels of zinc sulphate and application of recommended NPK along with 10 kg zinc sulphate ha-1 was found sufficient and economical in increasing the clove yield of garlic by 20.6 per cent. The same treatment resulted in higher farm income with the benefit cost ratio of 3.28. Slight yield reduction (5-7%) at all the four farms was observed for the higher levels of zinc sulphate addition (37.5 and 50 kg ha-1). The highest soil Zn availability, zinc accumulation and uptake by garlic crop were obtained with the addition of 50 kg zinc sulphate ha-1. Although there was a higher variability in the garlic crop response to zinc levels at all the farms, zinc sulphate addition at different levels considerably improved the growth and yield of garlic and also increasing the zinc accumulation in cloves and plants on zinc deficient soils.

A greenhouse experiment was conducted at Tamil Nadu Agricultural University, Coimbatore on two soils, deficient in S and Zn viz. Typic Ustochrept and Typic Haplustalf using rice as test crop to study the effect of green manure on soil Zn and S availability. Two sources of Zn (ZnSO, and EDTA-Zn @ 5 kg Zn ha-1) and S (gypsum @ 50 kg 5 ha-1) along with green manure viz. Sesbania aculeata @ 10 t ha-1 were applied. The GM application in sandy loam soil manifested higher availability of DTPA-Zn, more particularly with EDTA-Zn than in clay loam soil. Incorporation of GM with EDTA-Zn+ NPK enhanced the availability of Zn (2.91, 3.60 and 2.80 mg kg-1) at active tillering (AT). panicle initiation (PI) and harvest stages, respectively followed by GM aplication along with NPK+ ZnSO4 + gypsum. The highest sulphur availability was obtained with NPK+ GM + ZnSO4 gypsum at AT (21.38 mg kg-1) and PI (20.13 mg kg-1) and with the treatment, NPK+GM+ gypsum at harvest (26.38 mg kg) stages.