Nitrogen fertilization and management in tropical rice

It is the only important crop capable of growing in flooded soils because of its ability to oxide its rhizosphere. Rice responds almost universally to nitrogen fertilization. Nitrogen reactions are markedly affected by oxidation-reduction status of the soil, which largely depends on water management and soil physical conditions. Temporary flooding in most tropical areas causes loss of native or applied nitrogen. The responses of rice to nitrogen are minimal when tall varieties are used. In contrast, the responses are large and economical when higher rates are applied to short-statured varieties. Nitrogen recommendations for flooded rice are based on soil properties, plant type, solar energy, temperature, water management, and spacing.