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PLANETARY BOUNDARIES PART 5 OF 9 BIOGEOCHEMICAL FLOWS

Part 1 – Stratospheric Ozone Depletion

Part 2 – Loss of Biosphere Integrity

Part 3 – Climate Change

Part 4 – Ocean Acidification

The biogeochemical flows, this planetary boundary is referring to, is the phosphorus cycle and the nitrogen cycle. These cycles happen naturally in nature over time, and without our intervention, remain in balance.

Let’s start with nitrogen

Nitrogen makes up 78% of the air we breath and so, it is all around us. This gas is made of two atoms with triple bonds. These bonds are very difficult to break. Plants and animals, including us, need nitrogen to survive. We cannot use the nitrogen in the air and neither can plants. So how do we access this nitrogen?
Tiny microscopic bacteria that live in the soil take nitrogen from the air and fix it into the soil. These bacteria produce enzymes that break these triple bonds and put nitrogen into a form that is accessible to plants. We can then access our nitrogen requirements by eating the plants. Nitrogen is returned back into the system when plants and animals die or when animals urinate or produce manure. Plants take this nitrogen up from the soil to grow. There are also special bacteria that convert this accessible nitrogen into atmospheric nitrogen or nitrogen gas. Another name for this  gas is dinitrogen.

Commercial agriculture uses synthetically made nitrogen to fertilize crops but this chemical leaches into rivers and lakes when it rains and causes algae blooms. When the algae dies, bacteria break them down but consume all the oxygen in the water by doing so. These oxygen consuming bacteria turn the river or lake into a dead zone. It’s called a dead zone because no other aquatic life can survive in water without oxygen. America’s dead zone off the eastern coast is visible from space. 

You can see from looking at the planetary boundaries picture, that we have crossed this boundary into the red high risk areas. This means we have too many dead zones around the world because of nitrogen pollution in seas and lakes. Commercial agriculture takes a lot unhealthy shortcuts to produce food but affects the natural balance of nature and thus negatively impacts our ecology. Permaculture methods do not use chemical fertilizers but lets nature do the work for us. 


The Phosphorus Cycle

Phosphorus is found in rock especially sediment layers and with constant weathering, is released into the ground. Plants take up phosphorus from the ground and we take up our needed phosphorus from plants. When animals and plants die, this phosphorus is returned back to the soil or runs into the sea, becomes a sedimentary layer and in a few million years, pops up as a mountain exposed to weather again. It’s a really slow process.

Commercial agriculture has messed up the phosphorus cycle so badly, that it is becoming deplete in the soil. Phosphorus is mined and used in chemical fertilisers that commercial farmers use. Permaculture does not use synthetic fertlizers to grow crops and harmonises with nature’s processes. Permaculture is the sustainable and regenerative method of farming because it treats the land as a permanent source of nutrition by building top soil and not depeleting it.

Nitrogen and phosphorus cycles
The Phosphorus Paradox
Fritz Haber – his paradoxical life
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