Abstract
Lowland rice (Oryza sativa L.) is an important food crop for large world population. Knowledge of dry matter yield and nutrient uptake of rice during growth cycle is important aspect of mineral nutrition and improving yield. A field experiment was conducted during three years on an Inceptisol to determine dry matter yield and nutrient uptake during different growth stages. Plant samples were taken at initiation of tillering (IT), active tillering (AT), panicle initiation (PI), booting (B), flowering (F), and at physiological maturity (PM). Dry matter yield of shoot was significantly (P < 0.01) increased and having quadratic response in relation to plant age. Concentrations of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), zinc (Zn), manganese (Mn), iron (Fe), and boron (B) significantly (P < 0.01) decreased with the advancement of plant age. However, uptake of these nutrients was having significant (P < 0.01) quadratic increase with increasing plant age. Optimum concentration of macro- and micronutrients at different growth stages was established for lowland rice. These values can be used as references for interpretation of plant tissue analysis results for lowland rice. Among macronutrients, Mg was having maximum utilization efficiency (grain produced per unit of nutrient accumulated in the plant) and K was having minimum efficiency. Nutrient utilization efficiency was maximum for B and minimum for Mn among micronutrients.