Waste equals food, part I

Här skriver jag om en bok som hade mycket bra att säga om våra teman här på bokashi.se. Cradle to Cradle heter den — och finns bara på engelska än så länge. Då kändes det lika bra för mig (som har engelska som modersmål) att blogga om den på engelska. Läsvärt (boken alltså)!

Foto: Jenny Harlen

A while ago I found myself going through a book with a pencil in my hand (something I don’t do often!) enthusiastically underlining words, sentences, whole paragraphs. The book was Cradle to Cradle, Remaking the way we make things, by William McDonough and Michael Braungart. The authors are guided by a basic principle – Waste equals food – that the “waste” from one process can become a valuable resource for another.

Nature operates according to a system of nutrients and metabolisms in which there is no such thing as waste. A cherry tree makes many blossoms and fruit to (perhaps) germinate and grow. That is why the tree blooms. But the extra blossoms are far from useless. They fall to the ground, decompose, feed various organisms and microorganisms, and enrich the soil.

A cradle to grave approach, they say, is not sustainable because in many fields we’re not replacing resources at the rate we use them up. And not giving nature the chance to do its work…

Early agricultural communities continued to return biological wastes to the soil, replacing nutrients. Farmers rotated crops, letting fields lie fallow in turn until nature made them fertile again. Over time new agricultural tools and techniques led to quicker food production. Populations swelled, and many communities began to take more resources and nutrients than could be naturally restored. With people more tightly packed, sanitation became a problem. Societies began to find ways to get rid of their wastes. They also began to take more and more nutrients from the soil and to eat up resources (such as trees) without replacing them at an equal rate.

The same can be said about the way we’ve handled many of our resources, but I found myself most interested in the chapter on one of our most unseen resources: good old fertile soil. How we’ve taken and taken but not given back.

Soils now yield more crops than they naturally could, but with some severe effects: they are eroding at an unprecedented rate, and they are drained of nutrient-rich humus. Very few small farmers return local biological wastes to the soil as a primary source of nutrients any longer, and industrialzed farming almost never does.

But what I didn’t realise is that nature needs so much time to replace the soil we’re so happily using up, we see it as an unlimited resource that can’t run out. Much as we saw clean water and air many years ago.

Humans are the only species that takes from the soil vast quantities of nutrients needed for biological processes but rarely puts them back in a usable form. Our systems are no longer designed to return nutrients in this way, except on small, local levels. Harvesting methods like clear-cutting precipitate soil erosion, and chemical processes used in both agriculture and manufacture often lead to salination and acidification, helping to deplete more than twenty times as much soil each year as nature creates. It can take approximately five hundred years for soil to build up an inch of its rich layers of microorganisms and nutrient flows, and right now we are losing five thousand times more soil than is being made.

 Food for thought. And there’ll be more to come on the subject later!!