Calculator Inputs
Use one main page column. The input grid below adapts to large, medium, and mobile screens.
Example Data Table
This sample dataset illustrates one possible 30-day ecosystem budget.
| Variable | Example Value | Unit | Meaning |
|---|---|---|---|
| Study Area | 12 | ha | Total modeled site area. |
| Assessment Period | 30 | days | Window used for turnover estimates. |
| Biological Fixation | 18 | kg N/ha | New nitrogen from fixation. |
| Atmospheric Deposition | 7 | kg N/ha | Wet and dry deposition combined. |
| Fertilizer or Manure Input | 40 | kg N/ha | External management input. |
| Ammonification Flux | 52 | kg N/ha | Organic N converted to ammonium. |
| Nitrification Efficiency | 68 | % | Share of ammonium converted to nitrate. |
| Plant Uptake | 45 | kg N/ha | N retained in biomass. |
| Immobilization | 10 | kg N/ha | N stored in microbial or organic pools. |
| Total Measured Losses | 30 | kg N/ha | Denitrification, volatilization, leaching, and runoff. |
Formula Used
1) External Inputs
External Inputs = Fixation + Deposition + Fertilizer
2) Gross Available Nitrogen
Gross Available N = External Inputs + Ammonification
3) Estimated Nitrification Flux
Estimated Nitrification = Ammonification × (Nitrification Efficiency ÷ 100)
4) Biological Retention
Biological Retention = Plant Uptake + Immobilization
5) Total Losses
Total Losses = Denitrification + Volatilization + Leaching + Runoff
6) Net Balance
Net Balance = Gross Available N − Biological Retention − Total Losses
7) Retention Efficiency
Retention Efficiency = (Biological Retention ÷ Gross Available N) × 100
8) Turnover per Day
Turnover per Day = Gross Available N ÷ Period Days
How to Use This Calculator
- Enter the total study area in hectares.
- Set the analysis period in days.
- Select whether your flux inputs are in kg N/ha or g N/m².
- Fill in external inputs such as fixation, deposition, and fertilizer or manure additions.
- Enter internal transformation data, especially ammonification and nitrification efficiency.
- Enter retention terms, including plant uptake and immobilization.
- Enter loss terms, including denitrification, volatilization, leaching, and runoff.
- Press Calculate Fluxes to display the results above the form and below the header.
- Review the result cards, table, interpretation badge, and Plotly chart.
- Use the CSV or PDF buttons to export the current result set.
Frequently Asked Questions
1) What does this calculator estimate?
It estimates a practical nitrogen budget across fixation, transformation, retention, and loss pathways. The outputs help compare how nitrogen moves through a site during the selected period.
2) Is ammonification treated as a new input?
No. It is an internal recycling flux. The calculator adds it to external inputs only when estimating gross nitrogen made available during the selected period.
3) Why is nitrification estimated from efficiency?
Many field datasets report ammonification more often than direct nitrification. The efficiency method gives a transparent estimate when full nitrate production measurements are unavailable.
4) What does a positive net balance mean?
A positive balance suggests nitrogen remains after measured retention and losses. That surplus may indicate storage, later losses, or missing sinks not captured in the current dataset.
5) What does a negative net balance mean?
A negative balance means measured demand and losses exceed available nitrogen. This can signal underreported inputs, strong depletion, or high uncertainty in field observations.
6) Can I use g N/m² instead of kg N/ha?
Yes. Choose g N/m² in the unit field. The calculator converts values internally to kg N/ha, which keeps all results comparable.
7) Is this suitable for research publication?
It is useful for screening, teaching, and rapid budgeting. For publication-grade work, validate assumptions with site-specific measurements, uncertainty analysis, and peer-reviewed methods.
8) Which ecosystems can use this tool?
It can support cropland, pasture, forest, wetland, and restoration studies. The quality of the budget depends on how representative your input flux estimates are.