The influence of crop residues with different C: N ratios on the N2O emission from a loamy sand soddy-podzolic soil

The influence of crop residues with different C: N ratios on the N₂O emission from differently managed loamy sand soddy-podzolic soils was studied in a 50-day laboratory experiment. The application of crop residues into the soil increased the N₂O emission from the soil. The N₂O emission was lower from the poorly managed soil as compared to the soil with the high degree of cultivation. The crop residues form the following decreasing sequence in terms of their effect on the cumulative N₂O flow: cabbage > red clover > perennial grasses > straw of spring wheat. The composting of crop residues with a wide C: N ratio for 50 days did not exceed the critical value of the emission factor (1.25%), whereas, in the composting of crop residues with a narrow C: N ratio, the critical value of the emission factor was 1.3–2.0 times higher.