Soil Application of Silicon: Effects on Economic Yield and Nutrition of Phosphorus, Zinc and Iron in Rice (Oryza sativa L.)

A field experiment was conducted for the two consecutive seasons to evaluate the effect of diatomaceous earth as a silicon (Si) source along with recommended doses of fertilizer nitrogen (N), phosphorus (P), potassium (K) and zinc (Zn) as well as farmyard manure (FYM) in nine different treatment combinations on the yield and P, Zn and iron (Fe) nutrition of rice. The results showed a significant increase in grain yield of rice upon Si application with a concomitant improvement of P metabolism. Increased phosphatase activities in soil by the application of Si showed synergism between Si and P in grain (r = 0.91**) and straw (r = 0.90**). Zinc and Fe nutrition was affected by Si application through 600 kg diatomaceous earth ha⁻¹ with a decline in their concentrations in the grains by 39.6 and 25.7 per cent and in straw by 21.1 and 27.1 per cent, respectively over standard fertilizer practice. Better P metabolism as a results of Si fertilization may increase the production of phytic acid in rice which may retard translocation of micronutrients.