Cereals 2026: Phosphate guide helps growers boost efficiency

Improving how crops access phosphorus, rather than simply increasing fertiliser doses, is critical to enhancing farm productivity and water quality, according to a Phosphate Stewardship Guide launched at this year’s Cereals Event.

Availability, not supply, is often the limiting factor when it comes to phosphorus performance.

Adas senior research scientist Dr Christina Baxter says: “In many cases, soils already contain sufficient reserves, but only a very small proportion is available. Improving access is fundamental to improving performance.”

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On average, 10-20% of applied phosphate is taken up by the crop in the year of application.

The remainder becomes fixed to soil particles or stored in unavailable pools, contributing to inconsistent crop response and the gradual accumulation of ‘legacy’ phosphorus.

That challenge is driven by both physical and chemical soil processes.

Phosphorus moves very short distances, meaning roots must physically intercept it, while interactions with soil minerals can rapidly reduce availability following application.

Improving efficiency

The new guide was developed in collaboration with Adas and De Sangosse, bringing together research, field data and practical agronomy to address a widely recognised challenge across UK crops.

It outlines a system-based approach to managing limitations, based on improving availability.

This includes attention to placement, protection of applied phosphorus, using soil nutrient activators to unlock soil reserves, and the role of biological processes in mobilising nutrients.

“What’s becoming increasingly clear is that no single approach solves the problem,” explains Rob Suckling, technical manager at De Sangosse.

“We’re seeing more growers move towards combining strategies because each addresses a different part of the system. When those approaches are used together, that’s when you start to see efficiency improvements.”

Water quality

The guide highlights the growing importance of phosphorus management in the context of environmental stewardship.

P that is not taken up by the crop remains within the system and can be lost through run-off and erosion.

“Phosphorus is essential for crop growth, but in water it becomes a pollutant,” says Christina.

“Losses to watercourses contribute to eutrophication, which has a major impact on water quality. Improving how efficiently phosphorus is used on farm and minimising legacy P is a key part of addressing that issue.” 

The role of soils, roots and biology

The guide also highlights the importance of soil condition and biological processes in contributing to phosphorus availability.

“Phosphorus management isn’t just about fertiliser – it’s about how the whole soil-plant system functions,” says Rob.

“If root systems are well developed and the soil is functioning properly, the crop has a much better chance of accessing the phosphorus that’s already present.”

The aim of the guide is to provide practical support for decision-making at field level.

“This is about helping growers determine what could be limiting uptake in their own situations.

“Limitation can be identified through grain analysis, then managed more effectively once it’s understood whether the issue is access, availability or both,” says Christina

The Phosphate Stewardship Guide is now available from De Sangosse for growers, agronomists and distributors looking to improve phosphate use efficiency and nutrient stewardship on farm.