Silicon-enhanced seedling root-dipping for transplanted rice in acidic soil

Rice cultivation in problematic acid soils poses challenges for sustainable agriculture. To address this issue, seedling root-dip (SRD), rhizospheric nutrient management technique, in soil-water slurry amended with nutrient prior to crop transplantation has gained recognition. The study reported critical doses of silicon (Si) in SRD (Na ₂ O ₃ Si.9H ₂ O amended soil-water slurry) for three rice types (Hybrid: Arize 6444, HYV: Ranjit and Traditional: Mendri) from two acid soils (Sandy clay loam, SCL, pH 4.98 and clay loam, CL, pH 4.52) and 10 h incubation, respectively using the critical curve approach by Cate and Nelson. In SCL, the order of critical Si doses (mg/kg ^− 1 ) was Hybrid (275) > HYV, Traditional (225), while in CL, it was Hybrid (325) > HYV (225) > Traditional (175). From the field experiment I, the Si content and uptake was significantly higher in soil application (SA) of P-Zn-Si at tillering stage, while in Experiment II, it was comparable among the Si applied treatments (either SRD/foliar application). At harvest, the yield increase over control in Experiment I was SA of P-Zn-Si (130%) > P + MCRD + Zn-Si foliar + 50% RDP (96.12%) > MN + MCRD (30.28%) > MCRD (19.01) > MNRD (2.82%) while in Experiment II, the yield in Si added treatments along with 50% RDP gives a comparable yield with conventional method (100% RDP) and additionally, it can also save the P fertilizer input up to 50%. Based on this result, the study recommends the application of Si (SRD/foliar application) along with 50% RDP may sustain higher rice yields in acid soils.