Agroforestation of Grasslands in Southeast Asia: WaNuLCAS Model Scenarios for Shade-Based Imperata Control During Tree Establishment - Smallholder Tree Growing for Rural Development and Environmental Services - page 136

Fig. 6.1 Three stages in the development of an agroforestry system and the consequences for
Imperata control
C. Reliance on shade-based control once canopy closure has reduced light at the
ground level.
In practice this leads to the following three questions:
● What are the thresholds for the end of intercropping (end of Stage A) and the
start of effective shade-based control (Stage C) and how can a farmer recognize
these stages?
● How can the duration of stage B ( Imperata regrowth window) be minimized by
tree spacing and management for the different tree species?
● How can fire risk in stage B be minimized?
The WaNuLCAS 3.1 model (Van Noordwijk et al. 2004a), a generic tree-soil-crop
interaction model calibrated for the experiments of the Smallholder Agroforestry
on Degraded Soils (SAFODS) in Lampung (Indonesia) and Claveria (the
Philippines), is used here to explore the expected performance of various tree-based
systems in achieving shade-based Imperata control, especially aimed at reducing
the duration of Stage B (question 2).