Nutrient Management - Transplanted Rice

Nutrient management: Pre planting phase (residue management | organic materials and manure management) | Early vegetative - transplanted | Early vegetative - wet-seeded | Late vegetative | Reproductive phase | Ripening phase

From 2 days before transplanting to 14 days after transplanting (DAT), apply:

• Only a moderate amount of nitrogen (N) fertilizer, because the rice plant’s need for supplemental N is small during this period of slow initial plant growth.
• All of the required phosphorus (P) fertilizer, because P is important for early crop growth, especially for root development and tillering.
• At least half of the required potassium (K) fertilizer, because K contributes to greater canopy photosynthesis and crop growth.
• All of the required zinc (Zn) and sulfur (S) fertilizer.

Nitrogen (N)

Use the following general guidelines to determine the early application of N before 14 DAT:

• Typically apply 20–30 kilograms of N per hectare in seasons when yield response to N is between 1 and 3 tons per hectare.
• Apply 25–30% of the total N in seasons when yield response to N is greater than 3 tons per hectare.
• Eliminate early application when yield response to N is less than or equal to 1 ton per hectare.
• Do not use the Leaf Color Chart (LCC) with early N application.
• Reduce or eliminate early N application when high-quality organic materials and composts are applied or the soil has a high existing N content.
• Increase N application to 30–50% of the total N when older seedlings (more than 24 days old) and short-duration varieties are used.
• Increase early N application in areas with low air and water temperature at transplanting, and for low-tillering and large-panicle varieties.

Phosphorus (P)

As a general rule for modern rice varieties with harvest indices of 0.45–0.55, when most of the crop residue is retained in fields after harvest and little or no manure is applied to fields, apply 4 kilograms of P₂O₅ per hectare per ton of grain harvested to replenish the P₂O₅ used by the previous season’s crop (for example, 20 kilograms P₂O₅ per hectare for a grain yield of 5 tons per hectare). When all crop residues are removed from fields after harvest and there is little or no P added from organic fertilizer (such as manure) is negligible, apply about 6 kilograms of P₂O₅per hectare per ton of grain harvested to replenish the P₂O₅ used by the previous season’s crop (for example, about 30 kilograms P₂O₅ per hectare for a grain yield of 5 tons per hectare).

Harvest index. The ratio of grain weight to total aboveground plant dry weight.

Potassium (K)

Apply about 3.5 kilograms of K₂O per hectare per ton of grain harvested to match the export of K₂O with harvested grain when all crop residues are retained in fields after harvest. For example, apply about 17.5 K₂O per hectare for a grain yield of 5 tons per hectare. When all crop residues are removed from fields after harvest, apply about 12 kilograms of K₂O per hectare per ton of grain harvested to match the net export of K₂O with harvested grain and straw and maintain soil K fertility. For example, apply about 60 K₂O per hectare for a grain yield of 5 tons per hectare.

When the total K fertilizer requirement is relatively low (less than or equal to 30 kilograms of K₂O per hectare), apply all K fertilizer before 14 DAT. On sandy soils or when larger amounts of K fertilizer are required, apply about 50% of the required K fertilizer before 14 DAT.

Sulfur (S)

If the soil is deficient in S, apply about 2.5–3 kilograms of S per hectare per ton of anticipated crop yield before 14 DAT.

Zinc (Zn)

If the soil is deficient in Zn, apply about 5 kilograms of Zn per hectare as zinc sulfate before 14 DAT. Alternatively, apply zinc sulfate in the nursery seedbed, or dip seedlings in 2–4 % zinc oxide suspension before transplanting.