Here's an interesting article regarding top soil over on Time website. For years now we were warned about major fresh water shortages which is rapidly becoming a reality for a lot of countries rather than a crackpot conspiracy so why not take this a bit more seriously to add to your list of future worldwide doom and gloom.
Is soil really in danger of running out?
A rough calculation of current rates of soil degradation suggests we
have about 60 years of topsoil left. Some 40% of soil used for
agriculture around the world is classed as either degraded or seriously
degraded – the latter means that 70% of the topsoil, the layer allowing
plants to grow, is gone. Because of various farming methods that strip
the soil of carbon and make it less robust as well as weaker in
nutrients, soil is being lost at between 10 and 40 times the rate at
which it can be naturally replenished. Even the well-maintained farming
land in Europe, which may look idyllic, is being lost at unsustainable rates.
Why haven’t we heard more about this?
Probably because soil isn’t sexy. People don’t always think about how
it’s connected with so many other things: health, the environment,
security, climate, water. For example, agriculture accounts for 70% of
our fresh water use: we pour most of our water straight onto the ground.
If soil is not fit for purpose, that water will be wasted, because it
washes right through degraded soil and past the root system. Given the
enormous potential for conflict over water in the next 20-30 years, you
don’t want to exacerbate things by continuing to damage the soil, which
is exactly what’s happening now.
How does soil erosion happen?
Soil is a living material: if you hold a handful of soil, there will
be more microorganisms in there than the number of people who have ever
lived on the planet. These microbes recycle organic material, which
underpins the cycle of life on earth, and also engineer the soil on a
tiny level to make it more resilient and better at holding onto water.
Microbes need carbon for food, but carbon is being lost from the soil in
a number of ways. Simply put, we take too much from the soil and don’t
put enough back. Whereas the classic approach would have been to leave
stubble in the field after harvest, this is now often being burnt off,
which can make it easier to grow the next crop, or it’s being removed
and used for animal feed. Second, carbon is lost by too much disturbance
of the soil by over-ploughing and by the misuse of certain fertilizers.
And the third problem is overgrazing. If there are too many animals, they eat all the plant growth, and one of the most important ways of getting carbon into the soil is through photosynthesis.
What happens if this isn’t addressed?
There are two key issues. One is the loss of soil productivity. Under a
business as usual scenario, degraded soil will mean that we will
produce 30% less food over the next 20-50 years. This is against a
background of projected demand requiring us to grow 50% more food, as
the population grows and wealthier people in countries like China and
India eat more meat, which takes more land to produce weight-for-weight
than, say, rice.
Second, water will reach a crisis point. This issue is already
causing conflicts in India, China, Pakistan and the Middle East and
before climate change and food security really hit, the next wars are likely to be fought
over unsustainable irrigation. Even moderately degraded soil will hold
less than half of the water than healthy soil in the same location. If
you’re irrigating a crop, you need water to stay in the soil close to
the plant roots. However, a staggering paper was published recently
indicating that nearly half of the sea level rise since 1960 is due to
irrigation water flowing straight past the crops and washing out to sea.
Read the rest of the article;