New ideas are flowing down the Mamoni! Lately, the Ecofarms team has been getting into soil bioengineering. Otherwise known as a “lasagna bed”, which is a no-till type of sheet mulching. The concept of the lasagna bed is alternating layers of carbon-rich and nitrogen-rich biomass in a concentrated area to allow it to decompose over time. The biomass that takes the longest to break down will be put at the bottom, while the quickest will be placed towards the top. This allows for a slow yet constant regeneration of soil over time.
So how do we make it?
A few key things to keep in mind are how to make your lasagna bed environment suitable for decomposing microbes: aeration, warm temperature, little movement, and moisture. You want your biomass stable but not too compact that air cannot flow through it. Down in the tropics, we don’t have a big issue with it not being hot enough, especially considering it is currently the dry season. Being called the “dry” season — it becomes crucial to make sure moisture could stay trapped in our bed. Water plays a huge role in speeding up decomposition while keeping the environment oxygenated. Also keep in mind that it’s okay for your layers to mix! Now that you know the principles behind the lasagna bed, construction should be easy.
First, collect your biomass. Exactly what type of biomass will vary greatly according to your region. Your carbonaceous and nitrogen-rich matter will come in the form of dense, woody material, spong-ey plant mass, manure, green plant mass, leaf litter, etc. Using the most renewable, least energy-intensive materials has a lot to do with what organic yard waste, food scraps and agricultural by-products you already have available. This is another great benefit of biodiversity on a farm — as whether it will be harvested for food, animal fodder, medicine, or building materials — everything has a use.
Next, decide on a location for your bed and dig about 6 inches deep. You can also build this above ground with a barrier around it if weeds, pests, and fungi are a major concern. Now for the layering! Start out with your dead woody mass, for which we used slightly rotted sticks from around the farm. We intermixed coconut husks throughout each layer because they retain moisture well. We followed with chopped banana plants as our spong-ey plant mass and the banana leaves as our green plant mass. We added manure throughout the layers, usually above and below our green plant mass. Finally, we added leaf litter, more manure, and another layer of banana leaves. When we stepped back, we noticed our pit wasn’t quite full, so we repeated the process excluding more woody mass. To keep it moist in this dry season, we watered down the entire plant bed and covered it with a tarp. Now we wait!
Ask us about our soil in a month for an update!