Sunday, February 8, 2009

What Goes Around Should Come Around: Nutrient Cycling Part 1

Permaculture is a design system that is largely based on modeling natural systems, forests in particular (other ecosystems should also be modelled!). To successfully model something, a key component is first carefully observing it. Thus, one of the key principles of permaculture is listed as:

Observation: protracted and thoughtful observation rather than protracted and thoughtless labour.

If we observe a forest, we see that every autumn leaves of the trees fall to the forest floor where they are then broken down by bacteria, fungi, bugs, and worms (though the worms are a relatively new addition in North America and are changing some of the ecological dynamics of the deciduous forests). The breakdown of the leaves, and in fact anything else that the dies in the forest, results in the nutrients being released so that they can be taken up and incorporated in the growth of other plants and animals. The nutrients are cycled. Nothing is being wasted, it is all being reused and transformed - coming from the earth and returning to the earth. This fact is reflected in many of the creation myths that exist around the world. Many of them involve the first peoples being created from earth or mud. In one of the two biblical creation myths, there is a character named “Adam”, which apparently means “red earth”.

Another example is that we bury our dead in the earth. I haven’t looked into the origins of this, but it could reflect this knowledge of things coming and returning to the earth. Early peoples would have known that there is a transformation from life to death and from death to life (city dwellers have for the most part lost this connection, as they tend to not kill their own food, but instead opt to buy it at the supermarket). I have seen old Inuit camps in the tundra of the Northwest Territories where patches of wildflowers grow on small “refuse mounds” that contained the butchered remains of caribou or muskox. The nutrients contained in the bones, blood, and other animal parts support a diversity of life that is absent from the adjacent nutrient poor soils, even though hundreds of years may have passed since the mounds were made. The nutrients keep cycling and cycling and cycling. Native Americans were also said to bury fish with the corn crops to fertilize them and provide better growth. Similarly, gardeners today often amend their soils with bone and blood meal.

When our beloved cat Dr. Livingstone died, I buried him on the Hill behind her house that he used to frequent and planted some native prairie flowers on his grave. My kids know that this not only marks where he is buried, but also that he is being transformed into flowers. If this sounds bizarre, it is only because we have forgotten that this is how nature works and we, and everything else around us, are part of nature and its processes. Life to death, death to life.
Getting back to a wonderful process of nutrient cycling, I like to think of how the landscape developed in southern Ontario over the last 12,000 years or so since the glaciers melted. After perhaps a brief tundra/shrub tundra phase, spruce invaded the landscape creating the first forests. The spruce were then largely replaced by pines, which, in turn, were replaced by the deciduous species that we now have in the forests (varying in temporal and spatial abundance and composition, of course. I have the HARDEST time putting down statements without qualifying them… Nothing in nature is ever really so straightforward). During the majority of this 12000 year period, whatever died and fell to the ground was pretty much cycled back into the immediate system. There was no waste. Contrast that with our typical urban environments. In Kitchener, we have abundant lawns where the grass “wastes” are bagged and then picked up by the city every two weeks. The export of nutrients from the lawns typically necessitates the use of fertiliser to replace them. On of the typical trees planted in the city is Norway Maple. This, non-native tree, which seems to be particularly affected by fungal “tar spots” (unlike native maples), produces abundant leaves that make gardening around them difficult due to the shade. Again, in the fall these leaves (along with most other tree leaves in the city) are raked and bagged with all the carbon and nutrients being exported from the site. These “wastes” can and should be reincorporated into the site! What we are doing goes directly against what we observe in natural systems. Note that while I collect peoples bagged leaves for my garden, I don’t collect grass clippings as they often contain herbicides and pesticides. I have had a “hot” compost pile go cold as they beneficial bacteria within were killed by the addition of poisons in contaminated grass clippings that I added.

Another example, Kitchener has started a “green bin” program. It is an expensive program that is “designed” to save space in our land fills by picking up decomposable kitchen wastes and shipping them to another city for composting. So of course it involves buying plastic bins for everyone, as well as buying new trucks (or retrofitting old ones I don’t really know) with dual garbage/organic waste compaction systems. They evaluate the success of the program with the percentage of households participating. The higher the percentage, the more successful the program. However, in my humble view, the higher the percentage, the less successful the program is because people are NOT keeping the “wastes”, which are actually resources, onsite! Think of a nice environmentally conscious neighbourhood where most of the households compost their green and yard wastes. The city would designate the green bin program in this neighbourhood a “failure” due to their low participation! Now, the city does still promote composting, but I still think that adding the green bin program just adds on to a problem instead of fixing it.

Fixing the problem… A good design goes to the root of the problem and doesn’t just address the symptoms. Look at all of the costs associated with “fixing” the kitchen/lawn waste “problem”. Trucks costs and energy and pollution associated with their construction, operation, and maintenance, shipping the wastes to another city, labour, gas, exportation of nutrients, importation of fertilisers… My next entry will look at ways in which this problem can be fixed by modelling natural systems and the benefits of doing so. If have any other “cons” associated with the exporting of our yard/kitchen wastes, please add them in the comments section.