• Variety: Long duration variety needs more fertilizer than shorter duration variety.
• Soil: Light soil needs more split application of N and K compare to heavy soil.

Fertilizer should be applied based on a soil test and the desired  yield. The farmer should strive to obtain a fertilizer recommendation based on analysis of soil samples. This table serves as a guide.

When a soil test is not possible, general recommendations can be a good guide to applying fertilizer based on local recommendation.

• P and K fertilizer application: The best is at final harrowing just before seeding.
• N fertilizer application: Nitrogen is the most limiting factor in rice production. However, in seed production, judicial application of N fertilizer is  important since excess N facilitates vigorous plant growth that increases disease and insect infestation and delays fruiting resulting in a poor quality seed:
  • For every ton of yield required, 15 - 20 kg N is needed.
  • Apply in 2-3 splits.
  • Use more splits for longer duration cultivars.
  • Apply the first top dressing at the onset of tillering (21 days after seeding) and just after first weeding.
  • Apply a second top dressing at about panicle initiation - between 45–50 days after seeding.
  • Broadcast uniformly over the soil surface.
  • Don’t apply more than 30-35 kg N ha^-1 in a single split to minimize loss.
  • Use basal N only when it is necessary. Soils with high mineral releasing potential, e. g. Savanna soil, basal N may not be necessary
  • Use a Leaf Color Chart to estimate N need.

Because leaf color is affected by the sun, always shade the leaf being measured with your body. The same person should take the readings and at the same time of the day.