NRM Cawood’s extensive soil sampling has revealed stark differences in phosphorus levels across the UK and it advises that care is needed to manage levels to optimise crop production whilst limiting losses to the environment.
NRM has been collecting soil analysis data since 1995 and recently took a deep dive into the consolidated, anonymised data on soil phosphorus levels gathered from over 350,000 samples analysed from June 2024 to May 2025.
“Phosphorus (P) is a cornerstone of plant growth and productivity. Despite its importance, we’ve found that P levels vary widely across the UK,” says NRM’s Sophie Cath. “In Eastern arable areas, fewer livestock mean less manure recycling, so P levels often fall below target, leading to deficiency. Meanwhile, the livestock-rich northwest tends to show higher P levels as a result of years of regular manure use. Understanding these differences and tailoring management plans helps make sure that nutrients are managed efficiently and sustainably.”
Whilst arable soils overall were found to have maintained good levels of fertility, grassland soils shifted compared with last season. Sophie notes that a third of arable soils reached the target Index 2, similar to last year’s results.
“While arable results were steady, on grassland, 30% were on target, but 37% were higher,” she explains. “This small shift toward higher P levels shows why it’s important to keep fertiliser inputs in balance. This will help farmers to get the best from their soils without overloading them.”
Phosphorus management in the wider landscape
Managing phosphorus isn’t just about boosting crop growth: it’s about getting the balance right. Applying fertiliser accurately helps crops thrive while reducing the risk of pollution.
“P losses to water pose a major environmental concern,” adds Sophie. “Every year in England and Wales, around 2 million tonnes of soil and organic matter are lost to water. Much of it contains phosphorus, which can cause serious water quality problems when it runs off the land.
“To limit these losses to the environment, our experts suggest tailoring management practices to specific circumstances—particularly if your soils are in excess of P. Field management strategies like buffer strips and cover crops will help limit phosphorus losses, and careful nutrient planning and timing using expert analysis will help optimise crop production overall. Better decision-making informed by accurate and reliable results leads to improved soil health and compliance with sustainability objectives, both of which help to bolster the resilience of farming businesses.”
NRM advises growers to undertake testing. Its standard soil package provides soil indices based on RB209 guidance and an analysis of crop-available phosphorus, potassium, magnesium, and soil pH.
