08-10-27 Development of Microbial based Denitrification module

Previous model assumed that N-fluxes to denitrifier to be minor part of overall N-budget for soil and using a small time step allowing correct updating of anaerobic gas pools and Denitrifier biomass.  Recently the model was improved to be more robust also for longer integration time steps. The present step of development is in line with previous step attempting to create realistic results also when turnover of pools are very high in relation to estimated fluxes.

The previous step checked for a consistent estimation of production and consumption of the gas for each step in the chain from NO3 to N2. The present step is also including the exchange from the anaerobic domain to the air filled pore space (or  direct emission).  When the demand based on the rate functions for each of the transfers exceeds the available storage a common scaling to reduce the flux rate is adapted for each of the transfers are adapted.  This allows for a sharing of the available pool.

The time step for estimating fluxes of N gases are recommend to set according to the switch from (Numerical module) to be allow for at least 8 iteration per days. When using daily time resolution of input data we recommend the user to  set the switch (NitrogenCarbonStep) to independent of input time resolution.

The Nitrogen balance check  is now updated with consideration of both N I microbial biomass and N in the anaerobic gas domain.  New auxiliary variables NTotDenitStorage and  NTotGasStorage  are introduced as part of the Soil mineral N module.  The N transfer that represents the death of microbes are assumed to represent a N flux to the Litter1 organic pool.