Here at Maya Mountain Research Farm in the jungles of southern Belize, Chris and his small but dedicated team are managing an agroforestry system that ranges over 70 acres of land. As you can imagine they are spread thin. So over the course of one morning, I thought I would experiment with the concept of doing the least to achieve the most. In permaculture it's often a question of how best to match your energy expended to generate productive outcomes.
The rainforest is subject to torrential rainfall, there is a continuous flow of nutrients off the landscape. Most of the nutrients are locked up in the plants themselves rather than the soil which is prone to leaching. However in permaculture, we are seeking to create beneficial interactions around the systems we design. So, I turned my attention to a small stand of coffee plants with the idea to improve their vigour by setting up micro earth berms to capture and retain more moisture and nutrients. An earth berm is a mound of earth and organic matter placed on the lower side of a slope to create a mechanical barrier that will intercept nutrient flows.
The coffee stand is close to the house, beyond the chicken coop and on the way to the piggery. This is a zone of high activity and therefore any system implemented here has a good chance of benefitting from on going maintenance once I leave the farm. The house is located on an ancient Mayan plaza, chosen as the site is a plateau where water naturally flows away from. On several occasions over the previous two weeks, I spent time observing the water patterns in this area during rainy spells. My finer observations revealed where the leaf litter was accumulating, the depth of the silt trapped and the effectiveness of the breadnut tree buttress roots in halting further soil erosion.
Thanks to careful successional planting, this zone lent itself to the creation of a coffee stand. Initially, heavily planted out to banana, which produced biomass for soil conditioning and a quick return in bananas, subsequently breadnut has established itself providing erosion control and is one of the species that have contributed to a closed canopy. These are ideal conditions for coffee to prosper in as they prefer the cool sheltered shade that the mature canopy provides. From within this zone, I realised that I could find all the materials I needed to create the earth berms and I set to work.
I staked out the stacked heliconia in a “u” shape oriented down the slope for maximum effectiveness. I located and dug out a source of rich soil from a vaculative pond in the path of the erosional flow. In no less than a breath, the brave ducks were under my spade eagerly hoovering up the worms and grubs that I had unearthed. This earth became the plug behind the barrier. To this I added fallen banana trunk, which provides a slow release of nutrients back to the soil. From further down the slope, I quickly raked up a big bag full of mulch comprising leaf litter and decomposing tree matter which I spread around the base of the tree. The mulch will trap moisture and supress weeds too. Almost before I had finished, the chickens had moved in, scratching up the leaf litter! I'm not concerned, as any manure deposited is a quick hit of nitrogen for the tree. On another occasion, I will plant arachis pintio, a shade tolerant nitrogen fixing creeper on the up side of the slope, that in time will cover the area. All these components an interactions will support the soil food web necessary for bacterial and fungal activity that will ultimately contribute to building soil fertility.
So, for the duration of one morning, I managed my efforts attempting to match the energy expended to useful outcomes. I have demonstrated a technique taken from my permaculture toolkit, which can be repeated by future farm visitors. In sustainable agriculture, translating human capital into biological capital, can determine how effective we are. This example highlights a low tech human scale solution that with incremental maintenance, and should result in the coffee crop benefiting from increased localised moisture retension, improved soil biology and protection from soil erosion.