Is Permaculture just bunny hugging hippy shit about growing a few vegetables in a bucket or a serious way of dealing with our planetary existential crises? That depends on us and what use we make of it.
This study just came out. https://www.nature.com/articles/s43247-024-01405-8
Abstract
Permaculture is proposed as a tool to design and manage agroecological systems in response to the pressing environmental challenges of soil degradation, climate change and biodiversity loss. However, scientific evidence on the effects of permaculture is still scarce. In this comprehensive study on a wide range of soil and biodiversity indicators, we examined nine farms utilizing permaculture and paired control fields with locally predominant agriculture in Central Europe. We found 27% higher soil carbon stocks on permaculture sites than on control fields, while soil bulk density was 20% lower and earthworm abundance was 201% higher. Moreover, concentrations of various soil macro- and micronutrients were higher on permaculture sites indicating better conditions for crop production. Species richness of vascular plants, earthworms and birds was 457%, 77% and 197% higher on permaculture sites, respectively. Our results suggest permaculture as effective tool for the redesign of farming systems towards environmental sustainability.
a Topsoil (30 cm) organic carbon content on nine permaculture sites, direct control fields of locally predominant agriculture and German grassland (n = 387) and arable land (n = 1683)36. b Humic topsoil depth on nine permaculture sites and direct control fields of locally predominant agriculture. c Topsoil (30 cm) organic carbon stock on nine permaculture sites, direct control fields of locally predominant agriculture and German grassland (n = 387) and arable land (n = 1683)36. d Roughly estimated topsoil (30 cm) carbon sequestration (p = 0.044, χ2 = 5.05, df = 52) on six permaculture sites under the assumption that carbon level was originally sufficiently equal on site pairs and did not change on control fields. To set today as a baseline, the age of the permaculture sites was set to zero, and the age of the paired control sites was set to the negative age of the corresponding permaculture site. Here, the black line indicates a significant linear regression slope and 95% confidence interval. Dots indicate individual data points. Colors indicate sampling pair locations and gray dots indicate data points of literature data. Crossbars indicate the model-predicted mean and 95% confidence interval. Treatments not sharing the same letters are significantly different.
Great to see the evidence. It's still just related to farming/agroecology though - when we see the same evidence about the benefits of using PC design for health & well-being, education, livelihoods/business and governance, I'll be fully satisfied!
"The plant-extractable concentrations of soil phosphorous, potassium, magnesium, boron, and zinc were higher on permaculture sites than on conventionally fertilized soils of the control fields, which can be explained by a higher input of organic matter....." and surely also explained by the actions of the soil food web between plant roots (including crops) and soil fauna - that's what's running the cycle of OM breakdown/take up. So imo putting improvement just down to OM inputs is simplistic at best. Still great evidence tho