Although the seedlings we planted at our San José site are growing poorly and about 1/4 of them have not survived, this is a strategically important site for us. This is because it represents a worst-case scenario in terms of land-use: top-soil removal combined with heavy compaction by a bulldozer. Compaction causes severe and long-lasting damage to soils that can take decades to recover from. The community of San José, by electing to establish an agroforest plot on this site, have given us an opportunity to gauge growth and mortality rates Inga edulis on such areas and so evaluate their potential with respect to restoring them to productivity.
Since my last post for this plot the seedlings have gone through the stress of the dry season, a time when mortality in seedlings is greatest (their root systems are not very deep). We have experienced mortality for this site of 23%, much higher than for abandoned slash-and-burn sites where it ranges from 0 to 7%. Also growth has been much slower with surviving seedlings putting, on average, 2.7 cm a month. This compares poorly with the 11-18 cm average for our abandoned slash-and-burn sites. The preliminary conclusion we are drawing from this experiment is that the San José site will need at least an additional year of weeding and growth before we could contemplate trying to grow any crops on it.