Produce no waste

The old proverbs

Holmgren gives this principle two sayings: "Waste not, want not" and "A stitch in time saves nine".

The first is about abundance. What is squandered in a good season is missing in a lean one, and every place with a long dry summer knows this lesson. Winter rain that runs off the slope, green growth that is burned in spring, fruit that rots under the tree: each is a want prepared in a time of plenty.

The second is about maintenance. A small tear mended at once needs one stitch; left alone, it needs nine. On the land a rill on a slope can be stopped with a handful of brushwood and mulch before the next storm turns it into a gully. A gutter repaired in autumn saves the water the cistern needs in July. Timely care is the least visible way of producing no waste, and often the most effective, because it prevents losses that cannot be undone.

How it looks in nature

Nature does produce waste in the literal sense, at least for a while, and that is what makes the principle interesting. Oxygen began as the waste gas of bacteria that used sunlight to split water. Timothy Lyons and colleagues trace in their review how it built up in the atmosphere from about 2.4 billion years ago. For many organisms of that time, which lived without oxygen, it was a poison. Life adapted, and today almost every animal depends on that former waste. Given time, what burdens one organism becomes the livelihood of another.

Closer to the ground, decomposers do this every day. Fungi are among the few organisms able to break down lignin, the tough substance of wood. Dung beetles, woodlice, springtails and bacteria take apart what larger animals leave behind. Earthworms work on a scale that astonished Charles Darwin. In The Formation of Vegetable Mould through the Action of Worms (1881), his last book, he collected and weighed worm casts and estimated that in many parts of England worms bring more than ten tons of dry earth per acre to the surface each year, that is, more than 25 tonnes per hectare. The leaves they pull into their burrows become food for the soil life below. Compost gathers the same work in one place.

The lesson for design is not that nature leaves nothing over. It is that in a mature ecosystem almost every output already has a taker. Where takers cannot do their work, as in a waterlogged bog short of oxygen, matter piles up as peat. Where they are present, the same matter feeds the next round of life.

Where the principle works in the TerraWiki

• Compost turns kitchen scraps and garden residues into food for the soil instead of filling the bin.
• A composting toilet closes the loop the sewer breaks open and, after careful treatment, returns nutrients from human excreta to the land.
• Greywater gives lightly used water from sinks and showers a second use in the garden.
• Mulch and sheet mulching give prunings, leaves and cut green their first job as soil cover before they decay.
• Hügelkultur puts thick wood to use that would otherwise be burned.
• Biochar makes a stable soil material from wood too coarse for mulch, and terra preta shows how kitchen waste, ash and charcoal became fertile soil over generations.
• Biomass plants produce material on purpose, so that the land can supply its own mulch.
• The material cycle and the nutrient cycle follow these flows in detail and show where they leak.

At Sa Medada

Sa Medada is a slope in Jerzu, in Ogliastra on the east side of Sardinia, with mild winters and a dry season from about May to September. An old olive grove covers part of the land, and macchia grows on the steeper slopes. Both produce material every year: olive wood and leaves, and the shrubs of the macchia. As the page on the material cycle explains, burning olive prunings at the field edge is still common in southern Italy.

Project Eden goes the other way. In its plantings, pruned material is returned to the ground as mulch rather than removed, as the page on syntropic agriculture describes, so that it covers the soil and feeds soil life. The prunings of the nitrogen fixers already planted, among them Tephrosia, the coral tree and Inga edulis, can stay on the land in the same way; how much they give the soil where they grow has not been measured. In the dry season, material on the ground serves first as shade and only later as food, and compost is best built in the wet months, since an exposed heap soon dries out in the summer heat. A laboratory analysis of the soil does not exist yet, so we make no claims about how much humus the returned material builds.

Along the journey

The fifth principle, Use and value renewable resources and services, teaches us to value what renews; this one makes sure that none of it is squandered. The seventh, Design from patterns to details, steps back to the larger picture, because a taker for every output can only be found by someone who sees how the whole site fits together.