Nitrogen Deficiency
Nitrogen Deficientia
About Nitrogen Deficiency
Nitrogen deficiency is the most widespread nutrient limitation in flooded paddy cultivation. Because flooded wetland soils cause rapid denitrification and ammonia volatilization, available nitrogen depletes rapidly. Starvation restricts photosynthetic green area, reduces productive tiller counts per hill, and causes incomplete panicle grain filling. For a side-by-side comparison on telling nitrogen deficiency apart from water stress or disease, see our Symptom Diagnosis Guide.
Taxonomy & Features
- Old Leaves Yellowing First: Symptoms start uniformly on older leaves at the bottom of the plant, while younger leaves remain light green.
- Reduced Tillering: Stems are thin and erect; plants produce very few tillers, leading to thin stands.
- Lighter Grains: Panicles are small, short, and grains fail to fill completely, reducing grain weight.
Seasonal Outbreak Calendar
Outbreak risk and activity timeline for Nitrogen Deficiency based on seasonal climate patterns:
Prevention & Cure
Natural & Organic Methods
- Incorporate green manure crops (e.g., Sesbania, Sunn hemp) before planting.
- Apply well-decomposed farmyard manure (FYM) or vermicompost during land preparation.
- Intercrop with legumes to fix atmospheric nitrogen in the soil.
Chemical & Professional Control
- Apply Urea (46% N) in split doses: 50% at basal dressing, 25% at active tillering, and 25% at panicle initiation.
- Use Neem-coated Urea to reduce leaching and volatilization losses.
- Spray 2% Urea solution (20g Urea per Liter of water) for quick recovery of foliage in standing crop.
Frequently Asked Questions
Why does nitrogen loss occur so rapidly in flooded rice fields?
Flooded paddy soils contain both aerobic and anaerobic zones. Nitrogen fertilizer undergoes nitrification in surface water and is quickly converted to nitrogen gas and nitrous oxide (denitrification) in the anaerobic mud, or is lost through ammonia volatilization.
What is the best split schedule for applying Urea in paddy crops?
Apply 50% at basal transplanting, 25% at maximum tillering (21-25 days after transplanting), and 25% at panicle initiation. Using neem-coated urea slows nitrogen release and matches crop uptake stages.
Can the Leaf Color Chart (LCC) help manage rice nitrogen levels?
Yes. The IRRI Leaf Color Chart (LCC) allows farmers to match leaf greenness against 4-6 calibrated color panels. Top-dressing is applied only when the average leaf color drops below critical threshold (LCC score 4 for semi-dwarf varieties).
Recommended diagnostics based on crop family and symptoms:
Remedy Disclaimer & Safety Notice
This disease guide is for educational screening purposes only. Pathogen behavior, severity, and host susceptibility can vary dramatically based on seed variety, weather conditions, and regional microclimates. Chemical pesticides and organic treatments are subject to strict regional environmental regulations and registration mandates. Please verify all chemical registrations and review manufacturer safety labels carefully with local certified agronomists or agricultural extension service offices before applying.