Environmental Characteristics of Flood Water in Eastern India: Relevance to Flooding Tolerance of Rice

Data are presented on floodwater O₂, CO₂, HCO₃- and light in rice fields of flood-prone areas in Eastern India. Floodwater [O₂] of submerged or non submerged plants was low in the morning and increased to about 0.12 mol m⁻³ during the day (air saturated water contains 0.24 mol m⁻³ O₂); opposite trends occurred for CO,. Low [O₂] in floodwater in fields contrasted with measurements at an experiment station where floodwater was supersaturated with O₂ at 0.59 mol m⁻³ (equivalent to >50% v/v O₂). Results demonstrate the need for monitoring plots for relevance to field environments. Results from experimental plots demonstrated the possibility of manipulating floodwater [O₂] to increase submergence tolerance of rice during flooding in the field.