Following extreme weather conditions and one of the driest summers on record, farmers are being advised to test soil for potential nutrient lock up.
For farms considering what level of investment is feasible for the 2027 harvest, soil testing also offers the opportunity to better manage nutrient use efficiency (NUE) at a time when fertiliser prices show no sign of reducing.
“A lack of moisture in soil disrupts the movement of minerals and severely reduces microbial activity. Following this year’s drought, many areas in the UK will have soils that are in lock up and will need significant rainfall to recover. Knowing how much fertiliser will be needed for both soil health and plant uptake could enable growers to save thousands this year,” says Shane Brewer of Eurofins Agro.
Shane suggests that knowing the plant available nutrients, soil stock nutrients and the supply capacity in soil, can provide the benchmarks needed to more accurately prescribe inputs such as N,P and K.
“Our Fertilisation Manager test report can provide a crop-based fertiliser recommendation for over 300 crops and can be calibrated for specific crop varieties too. This is achieved by measuring the microbial biomass, microbial activity and fungal-to-bacteria ratio, to provide a kilos per hectare analysis of a field,” he adds.
Establishing this data at the point of planting, especially in dry soils with nutrient lock up, will enable growers to better forecast fertilisation, which will help with budgeting and NUE throughout the growing season.
In some areas of the UK, salinity and the build up of elements such as aluminium and hydrogen can also negatively affect soil health and are more common after drought. Shane suggests that rather than using previous years as a benchmark to estimate fertiliser requirements, growers may need to start afresh.
We have not seen such weather extremes in recent history and our soils are being damaged by conditions like flooding, drought and prolonged frosts. Using soil health data, we often see that balancing pH, optimising soil fertility and improving soil structure are just as important as simply applying more fertiliser. In short, our soils are working hard to withstand nature and we are just investing in the next crop rather than the future of our soil,” he says.
Over the summer months, as water has evaporated from UK soils, fertiliser has been locked up and will remain dormant until triggered by rain. These fertiliser minerals have become concentrated to the point of forming salt crystals that can change soil pH and make growing conditions less stable for newly planted crops.
“Plants establishing in drought-stricken soils will not be able to access the nutrients that have been locked up through mineralisation and sodification. Only through soil testing, to establish what plant available nutrients are present, will growers be able to save time and money during the growing season,” concludes Shane.
