Vol. 12, Issue 7 (2023)

Field experiments were conducted during Kuruvai and Navarai seasons at two different locations. Location – I was conducted in wetland (Field No. Q7 and A2) of Experimental Farm, Annamalai University, Annamalai Nagar, Komaratchi Block and Location – II were conducted in farmer fields at Kiliyanoor Village, Keerapalayam block, Cuddalore District, Tamil Nadu, India to study the effect of different silicon sources on post-harvest soil available nutrients (N, P, K and Si) of rice under different establishment methods. The field experiments were laid out in a split-plot design with two replications. The main plots comprised of M₁- Dry Seeded Rice (DSR), M₂- Wet Seeded Rice (WSR) and M₃- Transplanted Rice (TR) and subplots are S₁- RDF, S₂ - S₁ + 100 kg Si ha^-1 through Calcium Silicate + Silicate solubilising bacteria, S₃ - S₁ + 200 kg Si ha^-1 through Calcium Silicate + Silicate solubilising bacteria, S₄ - S₁ + 100 kg Si ha^-1 through Diatomaceous Earth, S₅ - S₁ + 200 kg Si ha^-1 through Diatomaceous Earth, S₆ – S₁ + 100 kg Si ha^-1 through Lignite Fly ash + Silicate solubilising bacteria and S₇ – S₁ + 200 kg Si ha^-1 through Lignite Fly ash + Silicate solubilising bacteria. Among the methods of establishments, transplanted rice recorded higher post-harvest soil available nutrients (NPK) status and dry-seeded rice registered the higher post-harvest soil available silicon status which was followed by wet-seeded rice, Regarding silicon sources and levels, DE @ 200 kg Si ha^-1 along with RDF recorded higher values for post-harvest soil available NPK status. This was followed by DE @ 100 kg Si ha^-1 along with RDF whereas calcium silicate @ 200 kg Si ha^-1 + silicate solubilising bacteria along with RDF recorded the highest post-harvest soil available silicon status followed by lignite fly ash @ 200 kg Si ha^-1 + silicate solubilising bacteria along with RDF. From this investigation, it can be concluded that DE @ 200 kg Si ha-¹ + RDF to transplanted rice is a viable practice to enhance the post-harvest soil available NPK status of rice and dry seeded rice applied with calcium silicate + silicate solubilising bacteria along with RDF is a viable practice to enhance the post-harvest soil available silicon status of rice.