Geoscience Reference
In-Depth Information
Our Indispensable Soil
As the bee collects nectar
and departs without injuring the flower
or its colour or scent,
so let a sage dwell in the community.
Buddha
Abstract
This chapter describes the significance of soil for humanity. Concepts
such as sustainability and nutrient balance are discussed. Most plants live in sym-
biosis with mycorrhizal fungi which spread their finely branched mycelium in
the ground and facilitate the uptake of nutrients but the fungal hyphae also help
to bind soil particles together into stable aggregates, providing a loose soil struc-
ture which is beneficial to the vegetation. Erosion, desertification and salinisation
are global problems that arise when we use the land in the wrong way. My own
experiences from research in Nepal and Tunisia serve here as current cases of
such problems and how they can be resolved, along with historical examples of
American farmers forced to abandon their farms and try their luck in California.
Lastly, the chapter discusses organic farming from a sustainability perspective.
When attending a meeting at Bristol University, I was treated to a rare moment of
popular science in a usually strictly academic environment. We were listening to a
PowerPoint presentation full of graphs and tables describing the state of Europe's
soil when a grey-bearded man wearing a woollen waistcoat approached the lectern.
Squinting at the audience, he held up an apple grown organically in his garden and
said it represented the Earth. He cut it in half with a knife and told us one half repre-
sented the oceans, with no soil for cultivation, and handed this piece to a colleague
sitting nearby, who proceeded to take a bite. He sliced the remaining half in two and
set one piece aside, saying it represented mountainous and polar terrain too cold or
inhospitable for agriculture. After discarding one-eighth of the apple as representing
urban areas, roads and polluted areas where crop growing was also impossible, he
was left with a small segment that he carefully peeled. “This is the arable soil left for
us to live on,” he said, holding the thin sliver up. “We need to take care of it.”
1
