How can nitrogen deficiency in plants be corrected?
Written by
Michael Sullivan
Reviewed by
Prof. Martin Thorne, Ph.D.When grown in nitrogen-deficient conditions, plants exhibit yellow leaves, growth inhibition, and reduced yields. Remediation of this situation begins with a soil test, which I require from my clients without exception. Last season, a soybean producer was able to avoid a yield loss of 30% because he performed a soil test before planting, resulting in a pH increase from 5.2 to 6.8.
Diagnose Accurately
- Use SPAD meters for leaf chlorophyll readings below 35
- Conduct soil nitrate tests (ideal: 25-50 ppm)
- Check petiole sap levels (corn needs 2,000 ppm at VT stage)
Choose Fertilizers Wisely
- Quick fix: 5% urea foliar spray (avoid midday to prevent burn)
- Long-term: Apply 150 lb/acre ammonium nitrate for cereals
- Organic: 10 tons compost/acre releases nitrogen over 8 weeks
Apply Strategically
- Side-dress corn at V6 growth stage
- Inject anhydrous ammonia 6-8" deep in fall for spring crops
- Drip systems deliver 65% efficiency vs. 40% broadcasting
Monitor & Adjust
- Re-test soil every 3 weeks during peak growth
- Track NDVI drone maps for 0.05-0.1 ΔNDVI improvements
- Adjust irrigation to prevent leaching in sandy soils
Maintain soil fertility year-in and year-out by planting nitrogen-fixing cover crops such as crimson clover. I work with a dairy farm in Wisconsin that was able to increase its soil nitrogen by 1.2% each year using crimson clover-vetch mixes in a cover crop rotation. Now, their corn averages 180 bu/A with a 25% reduction in synthetic fertilizer.
Excessive fertilization does more harm than good. Too much nitrogen burns roots and pollutes waterways. I have remediated fields after seeing 200 lb/acre of uptake where nitrates leached out in wells. Follow soil test recommendations, they are your road map for managing nutrient balance.
Read the full article: Nitrogen Deficiency in Plants: Signs & Solutions
