Abstract

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.

Keywords: Sesbania green manuring. Zinc and Sulphur fertilizers. Zn and S availability. Rice soils