Success of Modern Society Depends on Quality of Our Soil, Study States

Soil degradation has brought down more than one great civilization, researchers from the University of Witwatersrand write in a new study, warning the same fate could befall the modern world if measures are not taken to preserve soil quality.

Published in the journal Science, the report cites a drop in agricultural productivity due to soil erosion, rising salinity and dropping nutrients.

"Cultivating soil continuously for too long destroys the bacteria which convert the organic matter into nutrients," said Mary Scholes, a professor in the School of Animal, Plant and Environmental Sciences at Wits University.

Soil fertility baffled early farmers who were simply forced to move on until their land recovered. During the mid-20th century this began to change as soils and plants started undergoing routine testing to determine deficiencies.

This resulted in the creation of a worldwide agrochemical industry in order to respond to these shortcomings; however, while this triggered a sharp rise in food production, the solutions carried with them their own set of problems, including pollution and global warming, according to the researchers. In all, agricultural activity contributes to nearly one-third of greenhouse gas emissions, with more than half of these originating from the soil, they note.

The researchers argue that improved technology provides a false sense of security, with its unsustainably high use of fertilizers, irrigation and ploughing. Roughly 1 percent of global land area is degraded every year; in Africa alone, erosion has reduced yields by 8 percent.

"Soil fertility is both a biophysical property and a social property -- it is a social property because humankind depends heavily on it for food production," said Bob Scholes, a systems ecologist at the Council for Scientific and Industrial Research.

Feeding the world using an "organic" approach would not prove more environmentally sound due to the massive amount of land it would require, both argue.

According to the study, if lasting food and environmental security is to be achieved, the world needs an agricultural system that mimics "the close and efficient cycling in natural ecosystems, and that also benefits from the yield increases made possible by biotechnology and inorganic [fertilizers]."