To determine the separate and interacting effects of crop residue quality, residue management, soil type, moisture and temperature on emissions of N2O and CO2. The experimental treatments will reflect Northern European pedo-climatic conditions and include crop residues from relevant arable cropping systems. Data will be used for validating the N2O emission and SOC storage models in WP4, and for improving methodologies for up-scaling of N2O and CO2 emission estimates to national levels (WP5).

Specific objectives are to:

• determine effects of crop residues of different qualities on soil inorganic N dynamics and N2O/CO2 emissions, in incubation experiments with control of abiotic conditions

• determine effects of soil type, temperature, moisture and freeze-thaw events on N2O and CO2 emissions, for selected crop residues, in incubation experiments

• determine effects of crop residue quality, quantity and distribution, and interactions with soil pH, on field N2O emissions in Norway and Sweden, from autumn to spring.

WP3 is led by senior lecturer Maria Ernfors, SLU