Skip to main content
Calcimator

Cover Crop Nitrogen Credit

Estimate nitrogen credit from cover crops based on species, biomass production, and termination timing. Calculate fertilizer replacement value.

Inputs

lbs/acre

Results

Total N Credit

66 lbs/acre

First-Year Available N

33 lbs/acre

SpeciesHairy Vetch
Termination TimingMid (At bloom)
Second-Year Available N17 lbs/acre
C:N Ratio11
N Immobilization RiskNo
Fertilizer Replacement Value$33.00
Weed Suppression RatingGood
How to Use This Calculator
  1. Enter the cover crop species or blend and the above-ground dry matter in lbs per acre.
  2. Input the nitrogen concentration percentage (from a tissue test or species average).
  3. Set the termination method (incorporation, roll-crimp, herbicide) to estimate decomposition rate.
  4. Review the Total N in Biomass, Available N in Season 1, and Carryover N.
  5. Credit the Available N amount against your planned synthetic nitrogen application.

How the result changes with Biomass Production

Biomass ProductionTotal N CreditFirst-Year Available N
1,00019 lbs/acre10 lbs/acre
3,50066 lbs/acre33 lbs/acre
6,500113 lbs/acre57 lbs/acre
9,000113 lbs/acre57 lbs/acre

What each input means

Cover Crop Species
Species: 1 = Crimson Clover (80 lb N max), 2 = Hairy Vetch (100 lb N max), 3 = Winter Pea (60 lb N max), 4 = Cereal Rye (20 lb N max).
Biomass Production
Dry matter biomass in lbs per acre at termination. Typical legume: 2,000–4,000; cereal rye: 3,000–6,000 lbs/acre.
Termination Timing
When the cover crop is terminated: 1 = Early (pre-bloom, 50% credit), 2 = Mid (bloom, 75%), 3 = Late (post-bloom, 100%).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    Cover Crop Species = 2, Biomass Production = 3500, Termination Timing = 2 = 3 input(s) provided
  2. Calculate Total N Credit
    Total N Credit
    66 = 66
  3. Calculate First-Year Available N
    First-Year Available N
    33 = 33
  4. Calculate Species
    Species = sp.name
    Hairy Vetch = Hairy Vetch
  5. Calculate Termination Timing
    Termination Timing = timing.name
    Mid (At bloom) = Mid (At bloom)

Related Calculators

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Soil Science

Nutrient Balance Calculator

Calculate nitrogen, phosphorus, and potassium surplus or deficit by comparing fertilizer and manure inputs against crop removal rates.

Soil Science

Organic Matter Calculator

Calculate compost needed to raise soil organic matter, with estimates for water holding capacity improvement, CEC boost, and nitrogen mineralization.

Organic Farming

Cover Crop Mix Calculator

Design multi-species cover crop seeding mixes by balancing grasses, legumes, and brassicas with appropriate seeding rates and cost estimates.

Soil Health

Cover Crop Biomass Calculator

Estimate above-ground biomass, carbon contribution, and nitrogen credits from cover crop species based on growing degree days.

Soil Science

CEC Calculator

Calculate Cation Exchange Capacity and base saturation from clay content, organic matter, and exchangeable cation levels. Evaluate nutrient retention capacity.

More in Agriculture & Farming.