In recent weeks, the Sustainable Soils Alliance (SSA) received a response to a Freedom of Information (FOI) request submitted to Defra. The request was prompted by the Government’s 25 Year Environment Plan, in which funding provision for soil monitoring receives a rather non-committal mention:
“We will investigate the potential for research and monitoring…”
SSA’s FOI request revealed that of the total annual £68 million budget set aside for environmental monitoring in England (that is, for water, air and soil), the proportion allocated to soil amounts to just 0.41%.
There are numerous issues and complications hindering the development and implementation of a national soil monitoring programme; one of them clearly is budget.
When resources are few, there becomes a need to target sampling to priority areas. Soil sampling commonly relies on a grid whereby samples are taken at regular intervals. In this way, bias can be eliminated to a large extent. A fairly good, broad picture can be achieved, but localised variations can be easily missed.
For a nationwide monitoring programme, ‘conditioned Latin hypercube sampling’ may be more advantageous. The strategy utilises already available background data and creates a sampling strategy to achieve comprehensive coverage of the range of each variable considered.
Research has shown that optimizing sampling using this method can reduce the required sample size by around half compared with grid sampling, while continuing to achieve the same data coverage. If the result of such a system is to enable twice as many samples to be taken, and for conditions across a greater number of soil environment niches to be subject to monitoring, this is an exciting prospect for the 0.41% budget allocation.
Whether by grid or by cube, to get a national soil monitoring strategy off the ground, we simply have to get on the ground.