Fertilizer Calculator
Calculate optimal NPK requirements
Soil Test Results (lbs/acre available)
Fertilizer Calculator
Calculate the optimal fertilizer application rates for your crops based on soil test results, crop nutrient requirements, and field conditions. This tool helps farmers determine the exact amount of nitrogen (N), phosphorus (P2O5), and potassium (K2O) needed for maximum yield.
How It Works
Pro Tips
- •Always use recent soil test results for accurate nutrient calculations
- •Consider organic matter content and soil pH when planning fertilizer applications
- •Split nitrogen applications for better efficiency and reduced losses
- •Account for nutrient credits from previous crops and organic amendments
Common Crop References
Why Use Our Fertilizer Calculator?
Precise NPK Calculations
Get accurate fertilizer rates based on soil tests, crop requirements, and scientific formulas.
Soil Test Integration
Account for existing soil nutrient levels to avoid over-fertilization and save costs.
Save Time & Money
Optimize fertilizer use, reduce waste, and maximize return on investment.
Easy to Use
Simple interface with crop-specific recommendations and helpful guidance.
Multiple Units
Support for both metric and imperial units to match your farming practices.
Cost Analysis
Get detailed cost breakdowns and fertilizer efficiency calculations.
Frequently Asked Questions
How often should I test my soil?
Soil testing should be done every 2-3 years, or annually for intensive cropping systems. Test in fall after harvest for best results.
What do N-P-K numbers mean?
N-P-K represents Nitrogen-Phosphorus-Potassium, the three primary nutrients plants need. Numbers show the percentage of each nutrient in the fertilizer.
Should I apply all fertilizer at once?
For nitrogen, split applications are often better to reduce losses and improve efficiency. Phosphorus and potassium can usually be applied all at once.
How do I account for organic matter?
Organic matter releases nutrients slowly. Credit 20-40 lbs N per acre for each 1% organic matter, and adjust fertilizer rates accordingly.
What if my soil pH is too high or low?
Extreme pH affects nutrient availability. Correct pH first with lime (low pH) or sulfur (high pH) before applying fertilizers for best results.
Can this calculator work for organic farming?
Yes, but adjust for organic fertilizer release rates and nutrient availability. Organic sources typically release nutrients more slowly than synthetic fertilizers.
Try GLandGo Field Measure App
For more advanced and comprehensive measurement features—includingGPS area,distance,perimeter,SHP/GeoJSON import/export, and more—download our GLandGo Field Measure app.
Perfect for land surveyors, farmers, real estate professionals, and anyone needing precise field measurements.
