Glossary

C/N Ratio

A ratio measured by weight of the number of parts carbon to each part nitrogen, e.g. 10:1, 50:1, etc. This ratio is very high for fresh vegetal material (more than 100 for a straw) and decreases with the decomposition until 10 for humus. The value of this ratio allows to know the organic material evolution and its potential for mineralization:
  • when C/N < 15, there is nitrogen production
  • when 15 < C/N < 30, nitrogen needs are supplied
  • when C/N > 30 nitrogen consumption is assured by soil reserves