The Slimy World of Vermiculture
Earthworms! You may have heard that these little guys are great for the garden. They aerate the soil and thoughtfully deposit nutrients at the same time. Now this isn’t just great for our own small vegetable patches; it’s excellent for larger-scale composting, and is a potentially highly successful solution for soil fertility losses in many parts of the world [1]. Composting with worms is known as “vermicomposting”.
Worm excreta (worm casings) are rich in nitrate, Phosphorus, Potassium, Calcium and Magnesium. Adding worms to compost has allowed for less human labour, as the constant tunnelling of worms mixes the soil. People aren't needed to manually turn sitting compost heaps. Worm activities also hasten the decomposition of organic waste [1].
African earthworms used in vermiculture. (source).
A community vermicomposting project in Gagalphedi Nepal. (source).
Benefits from vermicompost have included increased yield, better growth of crops and suppression of disease [2]. As well, a huge benefit from vermicompost is carbon sequestration, where more carbon is retained in the soil than with synthetic fertilizer. A major contributor to climate change comes from the high amount of carbon released from soils in farms. Here vermiculture offers an alternative, more sustainable solution [2].
As well, the system seeks to work with the oft-discarded household waste. In Nepal, household waste normally collected by municipal waste trucks was turned into quality compost with vermiculture [3]. In this instance, the idea was not introduced by a foreign agency. Rather, a local Nepali NGO organized the youth to focus on the vermiculture initiative. This is empowering and likely to have longer-lasting impacts than the classic top-down style intervention of years gone by, as the youth are the “drivers of change” [3].
So... what's the cost?
In hillside communities where soil is often less fertile thanks to erosion and other factors, vermiculture is a potential solution.
Vermicomposting is a low-cost, viable alternative for many smallholder and subsistence farmers, because of its simple techniques and the fact that the worms do much of the work, reducing labour on the farmer’s part. Indeed, where infrastructure has been altered for vermicompost systems, the higher efficiency it gave the venture offset the improvement costs [1].
Vermiculture has huge potential benefits for smallholder farmers around the world, especially those in places with low soil fertility and where compost systems are already in place. The increases in crop growth and yields from successful implementation are grounds for its placement as a low-cost solution with high potential for subsistence farmers.
Vermicompost training in India. (source).