Seeding a forest with 1t of rock powder, a pinch of charcoal and 300kg of native seeds

Just before heading back to the city after one and a half months on the farm of PRETATERRA, we had the honor to participate in a second pilot project: Seeding a forest – Watch the video here!

On Wednesday night a white 1980s Hilux arrived on the farm carrying 300kg of Seeds on the trunk and Paolo Sartorelli in the front, the founder of Baobá Florestal and advisor to the team for this pilot. Paolo is already seeding forests for more than 10 years throughout different biomes in Brazil and has worked, inter alia, with the Xingu Seed Network which we mentioned in an earlier blog post. We unloaded the diversity of bags and stored them in the farm’s barn to protect the valuable asset from rain and weathering. Carrying the bags of different weight and form already gave a clue about what would await us on the next day. So, with a certain excitement for the next morning, we ended the day.

The next morning we spread a large blue tarp in front of the barn and started unpacking. Yesterday’s excitement grew with every new package we opened. An incredible diversity of forms, sizes and colors began to appear on the tarp. It felt like setting up an altar worshiping the biodiversity of our planet itself. Personally, I had never seen so many seeds from so many species in my live: Jatobá, Caju, Ipê, Guapuruvu, Aroeira, Capitão do Campo, Timburi, Mutamba, Pequi, Angico…these are only some of the 80 species I manage to remember. The seeds were mainly from the Brazilian Cerrado and Atlantic Rainforest, two miscellaneous and complex tropical ecosystems which must be studied for a lifetime to start unraveling their manifoldness.

In a next step we added the bacteria to the seeds, a couple of bags with gray powders that will benefit the germination and resistance of the young trees. Moreover, we added 300kg of gray rock powder which radically decreased the colorfulness of our earlier shining altar. After mixing everything with hoes, hands and feed there she was… our „muvuca“. The name goes back to the indigenous word muvuca which in Brazilian Portuguese refers to a „noisy agglomeration of people, esp. young people, in public areas, bars, etc., as a form of recreation; agitation, disorder“. Indigenous tribes have been using the technique to seed a variety of species together already for centuries which inspired this style of restoration. Muvuca as a name for the here presented restoration technique, however, was made popular by the above mentioned Xingu Seed Network. 

After measuring the tractors running time for a distance of 50m and calibrating the limestone spreader accordingly, we prepared the final mix by adding rock powder and some charcoal until the total mass of our muvuca was sufficient for the area of restoration. By the way, the aggregate is crucial for the muvuca as it homogenizes the mixture of seeds. Without it, the seeds would separate according to their size and we would end up seeding certain species concentrated in certain places. Other materials can be used as an aggregate, like sand, however, the mixture of rock powder, charcoal, bacteria and seeds seems to be just perfect as all these components are co-benefiting each other while simultaneously capturing carbon dioxide through enhanced weathering. We mixed the final muvuca with the tractor and filled it into the limestone spreader, covered the spreader with a tarp and pulled it to the field. 

For a successful seeding process the soil needs to be prepared with a harrow until the ground is fluffy and the grass roots are destroyed. In fact grass is the biggest enemy of the young growing forest, thus a control needs to happen 30, 60 and 90 days after seeding. To avoid the grass from coming back strongly, cover crops can be added to the muvuca, e.g. leguminosas, crotalária or pumpkin, which we added right in the beginning of the process. The actual spreading of the muvuca with the limestone spreader was eventually quite fast and less spectacular than mixing the seeds…and maybe a little dusty due to the rock powder we used. For the area of 2,7ha we restored about 1h of spreading time was sufficient with an additional 1h of hand seeding the areas where the tractor could not enter. If we would have planted the same area with seedlings, at least one day, if not two, would be necessary depending on the available man force. In a final step the harrow passed once more over the area where we seeded the muvuca to incorporate the seeds…and that’s it. 

After participating in this experience we must say that natural restoration through direct seeding seems to make a lot of sense. As a natural restoration technique we predict that it probably will start replacing the planting of seedlings in the future, especially for large scale restoration activities. As Paolo said at the end of the video „there is no way back once you start with direct seeding…with the agility, economics, ecology and socio-ambiental aspects the muvuca is almost unbeatable…“.

We feel like this was just the beginning of a long partnership were all three parties involved will take the idea of the muvuca even further. For example, how can we use the muvuca to seed an agroforestry system, how can we use the muvuca in silviculture or how can the muvuca play a role in forest restoration in temperate climate zones ? These are just three of the exiting outlooks where this ancient yet innovative technique may contribute a great deal.

Thanks for reading our blog. To learn more about direct seeding, rock powder and restoration, get in touch. Let’s seed carbon hubs together!

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