Improved process descriptions in the PESERA model

Table of Contents

1. Authors
2. Abstract
3. Introduction
4. General extensions to PESERA
   1. Grazing
   2. Fire
   3. Wind Erosion
5. Particular extensions to PESERA
   1. Mulching and/or maintaining ground cover vegetation within tree crops
   2. Retention of crop residues as litter layer at harvesting of arable and other crops
   3. Irrigation and water harvesting for croplands
   4. Invasion and clearance of unpalatable species
   5. Terracing and strip cropping
   6. Nitrogen budgeting and rotations
6. Other extensions to PESERA
   1. Mass movements
   2. Data collection calibration of PESERA against reservoir data
7. Conclusions
8. References

Nitrogen budgeting and rotations

The PESERA model already has a nitrogen cycling component, that was added for work on fertiliser application for upland UK environments. For simplicity, a single soil nitrogen store is simulated in the model. Nitrogen is added to the soil from litter-fall, fertiliser application, animal excretion and a small amount in precipitation; and lost in runoff and to plants. Plants take up nitrogen from this store, and by direct atmospheric fixation, returning it to the soil store and being removed to market. This component of the PESERA model then provides the response in biomass and yield to fertiliser application and nitrogen fixing crop rotations.