“Soil consists of a huge range of types of processes taking place. Some of which are chemical, some of which are physical, and biology,” said Professor Mary Scholes of the School of Animal, Plant and Environmental Sciences at Wits University.
Professor Scholes and Council for Scientific and Industrial Research systems ecologist Dr Bob Scholes’s paper, Dust to Dust, was recently published in the eminent scientific journal, Science.
Among other issues, the paper deals with modern civilisation’s failure to deal with soil fertility.
“The biology could be something as big as an earthworm or something as small as a virus. All of those biological organisms need carbon as their energy source. They obtain that carbon from material deposited into the soil such as tree leaves.”
As is the way of things, there is an entire world in the ground that most of us are unaware of which contains a delicate balance of widely diverse organisms exclusively dependent on one another.
“Not only do we have very large numbers of micro-organisms such as algae, bacteria, proto-viruses and viruses, but they are very diverse.
“There is a lot of redundancy, that is a number of organisms would be responsible for a particular process, but if that link breaks, there is going to be a problem,” Scholes said.
When the human link in the chain fails to fertilise soil, the system begins to degrade and it is the hapless worth-its-weight-in-gold micro-organism, previously happy to survive on the odd micro-chunk of appropriate carbon, that receives the sharp end of the stick.
These micro-organisms are responsible for healthy and sustainable soil.
Scholes dispelled the myth that produce today is less nutritious because of the amount of nitrogen-rich nutrients used to fertilise the earth and the selective breeding of plants.
The problem with fertiliser is the excess run-off pollutes rivers, aquifers and contributes to global warming. An easy example of nitrate pollution is Hartbeespoort Dam, well known for the algae blooms that have plagued its fetid water for decades.
The biological diversity and processes must be restored, said Scholes.
How? The paper sums it up best, saying that integration of best practices of soil sciences coupled with “… natural resource governance is the only viable route to both feeding the world and keeping it habitable”.