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

Mulching and/or maintaining ground cover vegetation within tree crops

It is common practice to clean-till between tree crops after every significant rain, and this method is applied to olives, almonds and vines. This practice increases depression storage and breaks up surface crusting, so maintaining good infiltration characteristics. It also removes competition for water from competing growth by eliminating herbs and grasses. One alternative strategy consists of allowing some herb growth between trees, and controlling this growth through cutting or herbicide application. This may be associated with reduced or zero tillage. Another strategy is to mulch the surface with plant residues which may be pruned material from the trees or imported material. In PESERA tree crops are generally represented by a look-up table which specifies cover in each month of the year. Mulching can then be represented by editing this table to increase the cover in this table. There has already been one pre-determined type for inter-sown or mulched tree crops, and this is edited in response to the chosen density of mulching.