How do I calculate the carbon footprint of growing cotton per kg of seed cotton?
For seed cotton, sum the field N2O from nitrogen fertiliser using IPCC defaults, CO2 from urea, diesel at 2.68 kg CO2 per litre and pump electricity at 0.710 kg per kWh, then divide by kg harvested per acre. The gin later splits it between lint and seed.
Field sources
- N2O and urea CO2 from nitrogen fertiliser.
- Diesel for tillage, spraying and haulage.
- Irrigation pumping, if the crop is irrigated.
Lint and seed
Seed cotton is split at the gin into lint, seed and waste. Allocate the farm figure between lint and seed by mass or value, and say which.
What is left out
Fertiliser manufacture, pesticides and seed are upstream inputs. Add them from supplier figures when you have them, and say which are missing.
Worked example: one acre of cotton (illustrative inputs)
- Direct N2O: 60 kg N x 0.01 = 0.600 kg N2O-N x 44/28 x 273 = 257.4 kg CO2e
- Indirect N2O: 60 x (0.10 x 0.01 + 0.30 x 0.0075) = 0.195 kg N2O-N x 44/28 x 273 = 83.7 kg CO2e
- Urea CO2: 130 kg x 0.733 = 95.3 kg CO2
- Diesel: 15 litres x 2.68 = 40.20 kg CO2
- Irrigation electricity: 400 kWh x 0.710 = 284 kg CO2
- Per acre: 760.5 kg CO2e
- At 0.60 t an acre: 760.5 / 600 = 1.268 kg CO2e per kg
IPCC 2006 Tier 1 defaults (EF1 0.01; 10 percent volatilised, 30 percent leached for irrigated land); AR6 GWP 273 for N2O. Fertiliser rates, litres, units and yield are illustrative, and fertiliser manufacture is not included.
What Senseible does here
Senseible reads diesel, electricity and fertiliser invoices into dated, fingerprinted records that support a farm or crop figure. Field emissions such as N2O and methane are calculated with IPCC defaults in your method note and labelled as estimates, not measured values.
Sources: 2006 IPCC Guidelines, Volume 4 AFOLU, Chapters 10 and 11, IPCC AR6 WG1, Chapter 7, Table 7.15 (GWP100), CEA CO2 Baseline Database, version 21.0
Last reviewed 2026-10-21.