Soils used for fruit, vegetable and ornamental production are in the front line for controlling climate change. This has become part of the cross-compliance demands for good agricultural and environmental condition in the requirements of the Rural Payments Scheme.
Minimising soil erosion, maintaining soil cover and increasing organic matter are criteria for growers’ payments. Failures in fulfilling these requirements may lead to reduced payments.
Statutory importance of this degree should mean a good scientific understanding of soil development and properties. Regrettably, that is not the case. Research support has diminished substantially over the past 30 years. Even simple questions such as "what is soil?" cannot be fully answered.
It is best regarded as a very thin mixture of finely degraded rock particles, organic matter, moisture, air and nutrients interlaced with incredibly active microbes, macroflora and fauna. Soils are live and supply ecosystem services that are the critical basis for terrestrial food supplies.
Humans are now requiring another service from soils as repositories for the excessive amounts of CO2 we produce. Nature’s carbon cycle converts CO2 via photosynthesis into plants that eventually die and are incorporated as organic matter in soil. Politicians have latched onto this property as a means for reducing the adverse effects of climate change. As a result, growers have become major agents for mitigating global warming.
Considerable changes in husbandry are needed for the success of these aspirations. Minimal tillage, rotational cropping, cover and inter-row planting, preservation of residues and encouraging soil micro- and macro-biology will aid CO2 storage. Replanting hedgerows, contour cropping and continuous ground cover will reduce soil losses by wind and water erosion.
That means considering soil management as a long-term process compared with short-term profitability. Here’s the rub. Politicians must fund growers for use of their soils as CO2 stores. Up until now this type of payment has been under the aegis of the EU’s Common Agricultural Policy. After Brexit, finance must come directly from UK taxation.