Data farming provides new insights on soil fertility
Scientists from the British Geological Survey and NRM Laboratories are using soil data to assess soil fertility.
Maps show that the pattern of more acidic soils – which can reduce soil fertility – increasingly reflect geology and typical rainfall patterns across England and Wales. In recent years, less agricultural lime has been added to farmers’ fields to neutralise soil acidity.
This approach uses soil measurements to monitor how key soil properties change nationally and regionally. By using soil measurements and locations from thousands of farms, scientists can create maps and assess changes in properties that influence soil fertility and crop yield.
The study which is published in the European Journal of Soil Science focused on soil data between 2004 and 2015 for five important soil properties or indicators. They were soil pH, phosphorus, potassium, magnesium and soil organic matter – in both arable and grassland systems.
Results were encouraging, despite some difficulties in using farm data for monitoring purposes. One advantage of the farm data is that because there are so many samples, maps of soil properties can help to identify regional issues sometimes missed by other surveys.
Research leader Barry Rawlins said, “Because less agricultural lime has been applied to agricultural soils over recent years, we increasingly see natural factors influencing the patterns of soil acidity across England and Wales.
Agricultural soils further to the north and west generally have a smaller capacity to neutralise soil acidity because of the underlying geology, said Dr Rawlins. The greater quantities of rainfall in these areas reduce that capacity further.
“This is less of a problem in the south and east,” he explained. “Farmers need to be aware of these differences because acidic soil is less productive – and they need to apply more agricultural lime to their fields.”
Around 40% of farmers’ fields across England and Wales have concentrations of soil potassium below optimum and around 25% have below optimum soil phosphorus levels. Areas deficient more than six years ago were also deficient over the last six years.