Actualizado: 13 de ago de 2020
10 weeks after the first intervention in the coffee lot there has been an enormous growth pulse in the system and the species that were introduced are growing well
10 weeks after the intervention, the coffee lot has exploded in new growth and many, many new natural regeneration species have emerged. The short to mid term cover crop was largely successful, especially the canavalia and cow pea (Vigna unguiculata). The pigeon pea seeds I suspect were bad as very few have germinated. We have had alot of rain since the system was planted.
The large Inga trees that I cut back are resprouting rapidly and will contribute to closing the canopy and creation of biomass. When I take out the old coffee I will also cut back the inga and eventually take it out of the system to give way for the new inga trees from seed at 3x6.
Gliricidia and Senna reticulata
The tree seed mix of Gliricidia sepium, Senna reticulata, and Acacia mangium have germinated well with at least 1 tree growing at the base of approximately 80% of coffee trees. What most impresses me are the quantity and diversity of native trees that are growing, at least 20 species with 2 endangered species that I readily identified. The diversity of non-woody natural regeneration is incredible with an estimated 80 different species growing. This is compared to before the intervention where there were approximately 30 species in total growing, including the coffee and inga.
This tree Guácamo (Calophyllum sp.) was a very common primary forest species in this community 70 years ago that has excellent quality wood but has been cut down close to extinction in this region and is of special interest to plant and grow as many as possible. The seed must have been in the seed bank and with the heavy canopy of the abandoned coffee system it germinated.
The Bracken fern has grown especially aggressively and I have cut it back twice in the 10 weeks. I also spot applied one or two handfuls of lime to each clump, and they are easily cut back with the machete. There seems to be some ferns that are dying back on their own, I left some clumps to see if with the lime I applied they will be affected. Some are over 2m tall.
In some sections a soft vine has taken over, I imagine that it is there to tie up the nutrients that were released by the cut biomass and it will be interesting to see if there is an ecological mechanism to kill the vine and incorporate the nutrients back into the system.
As pigeon pea seeds become available from the bushes close to the house I will plant out one in between the coffee plants. It will end up 1.5mx1.5m although with enough seeds a much higher density is possible.
This is Yarumo (Cecropia sp.) a sun loving secondary tree that mostly grows through low cover and needs shade to germinate but reaches for the sun and occupies the emergent strata. This is a straight and hollow trunked that is non woody, with short branches that hold large multi pointed leaves. The fruits are small and grow direcly from the trunk and are very sweet and loved by many different bird species. In comparison, the papaya tree is another straight and hollow trunked tree that is non woody with short branches that hold large multi pointed leaves. The main difference between the two is that the papaya produces fruits that are valuable in local markets and also are high quality people and chicken food and high in vitamins but the yarumo does not. And is a great example of where we can imitate natural regeneration with production plants, these both trees are fast growing trees that at the end of their life cycle will leave thick hollow trunks on the soil that will break down rapidly and feed the next consortium in the system. But by planting the papaya we are able to cultivate fruit that create income, food security, and is great chicken food without leaving a successional niche open in the system.
Banana clump after intervention and 10 weeks later:
Coffee lot after intervention and 10 weeks later:
This system was a non-productive abandoned coffee lot, and the trees in the system were slowly dying of disease especially the coffee and inga which are later succession species and were artificially supported by chemical fertilizers under the previous owner. Eventually what would have happened is that the coffee and inga would have died giving way to the species that have emerged over the last 10 weeks but it could have taken years. By cutting and recycling practically all of the biomass in the system and planting out early secondary trees I have sped up the natural process and the system is metabolizing the nutrients that were previously biologically held in the biomass and unavailable for the early secondary trees like the rubber tree (Ficus sp.) and the spiny cedar (unknown scientific name). The quickly biodegrading biomass as well as the increase in sunlight triggered a massive growth pulse in the system and an incredible increase in photosynthesis even in the native shade trees I left almost without pruning. The 3 tree species I introduced to the system are service trees that grow quickly, fix nitrogen, and resprout strongly when pollarded. These trees will be the motor for the system´s fertility over the next few years. In a year I will take out the old coffee and prune the system again, although not as intensively, and at the same time I will plant the new coffee along with the production species (banana, fruit, inga, and hardwood overstory) that will form the next consortium in succession. With every prune the system´s fertility grows and the system moves forward in succession.
After this first intervention I can clearly identify increased fertility, increased photosynthesis and increased biodiversity. It will be interesting to see how the system develops.