Nutrients

N Nitrogen
P Phosphorus
K Potassium
Ca Calcium
S Sulfur
B Boron
Cu Copper
Fe Iron
Mn Manganese
Mo Molybdenum
Zn Zinc

Rice - Growth retardation

Symptoms
The leaves of the deficient plant are erected and dark green. Older leaves turn brown and die. Red and purple tints may develop in some varieties.

Reasons
Phosphorus deficiency. Susceptibility to P deficiency varies among rice cultivars. Soils particularly prone to P deficiency: - Coarse-textured soils containing small amounts of organic matter and small P reserves (e.g. sandy soils in northeast Thailand) - Acid sulfate soils in which large amounts of active Al and Fe result in the formation of insoluble P compounds at low pH.

Rice - Growth retardation

Symptoms
The leaves of the deficient plant are erected and dark green. Older leaves turn brown and die. Red and purple tints may develop in some varieties.

Reasons
Phosphorus deficiency. Susceptibility to P deficiency varies among rice cultivars. Soils particularly prone to P deficiency: - Coarse-textured soils containing small amounts of organic matter and small P reserves (e.g. sandy soils in northeast Thailand) - Acid sulfate soils in which large amounts of active Al and Fe result in the formation of insoluble P compounds at low pH.

Phosphorus deficiency made worse by

  • Acidic or very alkaline (calcareaus) soils
  • Low organic matter
  • Cold or wet conditions
  • Crops with a poorly developed root system
  • Soils with low P reserves
  • Soils with a high phosphate capacity
  • Iron rich soils

Phosphorus is important for

  • Vigorous early crop
  • Healthy root system
  • Uniform crop development
  • Promotes tillering
  • Improves grain yield