In our report Sustainable Use of Soil, published this week, the Royal Commission on Environmental Pollution set out to establish whether the effects would be sustainable if current human activities that affect soils, and present trends, continued unchanged for the next 100 years.
Sustainability in the use of soils does not mean avoiding all changes, or trying to restore damaged soils to some pristine state. But it implies that human activities ought not to deplete resources of soil at a faster rate than these can be replenished by natural processes or human intervention. We must be careful not to cause lasting damage to the natural resilience of soils, about which we have little understanding.
At global levels there are extensive areas degraded by over-exploitation and mismanagement. Within the next 20 years the world will probably begin to run out of land that can be brought into agricultural use. It will also be increasingly difficult to meet the rising demands for water. Feeding the world's growing population may be made considerably harder by climate change.
The UK has fertile soils and there is no widespread damage of the kind apparent in many other countries. The UK might have to become more self- sufficient in food in the 21st century - we might even become a net exporter of food. That makes our own resources of soil even more precious.
The Royal Commission believes that there ought to be an explicit policy to protect soil. Our central recommendation is that the Government should draw up and implement such a policy. The aim will be to ensure that the use made of soils for all purposes is the optimal sustainable use.
The pressure on UK soils comes not only from agriculture, but extraction of peat and other minerals, from contamination caused by industrial operations, from various forms of waste disposal, from atmospheric pollution and, last but not least, from urbanisation. The continuing transfer of substantial amounts of rural land to urban uses, especially in fertile lowland areas and areas of high aesthetic value, is a major threat to the sustainable use of soil resources. Already, built-up areas and roads cover one-eighth of England. If such growth were to continue at what was the average annual rate between 1945 and 1990, more than a fifth of England would be covered by built-up areas and roads by the end of the next century.
The solution must lie in recycling previously developed land for new uses. This depends on removing any contamination that would be an obstacle to re-use. At the present rate of remediation however it could take 100 years to remediate soil on the contaminated sites that now exist. We need to find ways of harnessing marketing forces to help achieve more effective recycling based on the best practicable environmental option. But this will not be achieved by market forces alone, and we recommend a more pro- active approach by government agencies.
Wise stewardship of soils is almost always in the direct interests of farmers. But government departments must do more to ensure that they have adequate advice about soil conservation. A welcome development is integrated farming systems that optimise inputs of pesticides and fertilisers, and employ techniques such as crop rotation and natural pest and disease control.
The new Environmental Agencies have a very important role in making up for the previous neglect of soils. Their new functions in relation to contaminated land should be brought into effect as soon as possible. The other legislation applying to them should be reviewed within three years to ensure that they seek the best practicable environmental option in all their activities.
Sir John Houghton is Chairman of the Royal Commission on Environmental PollutionReuse content