Nitrogen Fertilizer Response m³/yr Gain

Calculate paired before/after/control annual volume-growth contrasts, retaining signed response; observational contrasts alone do not establish causal fertilizer efficacy or an application rate.

Description

A paired before/after control contrast can describe treatment-associated volume-growth differences.

A paired before/after control contrast can describe treatment-associated volume-growth differences. Annualizing each pair requires its own elapsed interval.^[1]

Calculate paired before/after/control annual volume-growth contrasts, retaining signed response; observational contrasts alone do not establish causal fertilizer efficacy or an application rate.

When to use Nitrogen Fertilizer Response m³/yr Gain

Use this tool to calculate paired before/after/control annual volume-growth contrasts, retaining signed response; observational contrasts alone do not establish causal fertilizer efficacy or an application rate.

Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.

How to use Nitrogen Fertilizer Response m³/yr Gain and understand its results

Gather the tree inventory, plot measurements or model parameters. Check diameter, area, time and moisture conventions; keep paired observations aligned.
Enter treatedBeforeVolumesM3PerHa, treatedAfterVolumesM3PerHa, controlBeforeVolumesM3PerHa, controlAfterVolumesM3PerHa, elapsedYears using the field table and calculation rules, then run the tool.
Read pairedControlAdjustedVolumeResponseM3PerHaYear, meanControlAdjustedResponseM3PerHaYear. The explanation below defines the units, signs, ordering and any flags or placeholder values.
If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.

Input field	Meaning	Value type; see rules below	Requirement
treatedBeforeVolumesM3PerHa	Treated before volumes m3 per ha	list of number	Required
treatedAfterVolumesM3PerHa	Treated after volumes m3 per ha	list of number	Required
controlBeforeVolumesM3PerHa	Control before volumes m3 per ha	list of number	Required
controlAfterVolumesM3PerHa	Control after volumes m3 per ha	list of number	Required
elapsedYears	Elapsed years	list of number	Required

Pair four nonnegative volume inventories in m³/ha with positive elapsed years. Return signed pairwise adjusted m³/ha/year responses and their unweighted arithmetic mean.

Paired lists must be nonempty and have equal lengths.

adjusted response=(treated after−treated before−control after+control before)/elapsed years

Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.

Output field	Meaning	Value type
pairedControlAdjustedVolumeResponseM3PerHaYear	Paired control adjusted volume response m3 per ha year	list of number
meanControlAdjustedResponseM3PerHaYear	Mean control adjusted response m3 per ha year	number

json

{
  "input": {
    "treatedBeforeVolumesM3PerHa": [
      10,
      20
    ],
    "treatedAfterVolumesM3PerHa": [
      20,
      40
    ],
    "controlBeforeVolumesM3PerHa": [
      10,
      20
    ],
    "controlAfterVolumesM3PerHa": [
      15,
      30
    ],
    "elapsedYears": [
      1,
      2
    ]
  },
  "output": {
    "pairedControlAdjustedVolumeResponseM3PerHaYear": [
      5,
      5
    ],
    "meanControlAdjustedResponseM3PerHaYear": 5
  }
}

Limitations and assumptions

The contrast does not by itself establish causal fertilizer efficacy or an application rate.

Numeric inputs and returned numeric values must be finite; an unrepresentable returned value produces an error. Numeric lists are limited to 100,000 entries; the rules above may require smaller limits. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.

Alternative or Complementary methods

Use Improved Seed Genetic Gain Height Percent: Compare matched improved/control height observations using pooled and paired relative gains; signed reductions remain and contrasts alone do not attribute causal genetic gain. For a complementary task, use Culmination Age MAI PAI: Audit sampled cumulative production through MAI and interval PAI, returning first age of sampled MAI maximum; distinct from existing one-interval increment formulas and no continuous unsampled peak inferred.

References

Nitrogen Fertilizer Response m³/yr Gain — tool.io

Similar or alternative tools

Improved Seed Genetic Gain Height Percent
Compare matched improved/control height observations using pooled and paired relative gains; signed reductions remain and contrasts alone do not attribute causal genetic gain.
Culmination Age MAI PAI
Audit sampled cumulative production through MAI and interval PAI, returning first age of sampled MAI maximum; distinct from existing one-interval increment formulas and no continuous unsampled peak inferred.