ESRF News March 2026

March 2026 ESRFnews

PHOSPHORUS FERTILISER

was added , more of the phosphorus instead formed

magnesium - phosphate phases , which are even more

readily available to plants ( Chemosphere 331 138759 ) .

Synchrotron X - ray diffraction at the ESRF ’ s ID13

beamline was used to identify these mineral phases

unambiguously , confirming that phosphorus chemistry

can be steered at the point of fertiliser production .

According to team member Johannes Lehmann at

Cornell University in New York State , the researchers

now want to go beyond improving phosphorus

availability and design biochars that can actively

capture phosphorus from solution – for example from

agricultural wastewater – before it is lost downstream .

Synchrotron methods have also revealed how the

behaviour of phosphorus in soils can be shifted by

nitrogen chemistry . Back in 2020 , micro - XANES at

the ESRF ’ s ID21 beamline showed that ammonium -

based fertilisation – especially when combined with a

nitrification inhibitor can mobilise otherwise poorly

soluble apatite phosphorus by acidifying the root zone

Co authored by ID21 scientist Hiram Castillo Michel

the work demonstrates once again that nutrient availability

depends not just on how much is applied but on chemical

form and local reactions Sci Total Environ 715 136895

Whether by changing tillage reformulating fertilisers

or capturing nutrients from waste streams the aim is the

same more uptake less loss The stakes are especially high

for nitrogen which is costly and highly carbon intensive

to produce see The other fertiliser problem left That

makes it crucial to understand what really happens after

nutrients reach the plant a question now being tackled

“ ESRF

capabilities are

critical for

understanding

how legacy

phosphorus is

stored and

transformed

under different

management

systems . ”

with high - resolution ESRF imaging .

Last year , Emil Kristensen at the Technical University

of Denmark ( DTU ) and colleagues used hard X - ray

nano - holotomography at the ESRF ’ s ID16B beamline

to track fertiliser nanoparticles ( in this case manganese

dioxide ) inside living leaves in three dimensions . Relying

on the EBS ’ s high coherence and stability , the team could

perform phase - contrast imaging at better than 200 nm

resolution of hydrated plant tissue , avoiding the fixation

and dehydration normally required for nano - scale X - ray

microscopy ( Figure 2 ) .

The reconstructions revealed where foliar - applied

nanoparticles accumulate and how they move through

leaf structures , providing a direct view of nutrient

delivery pathways that previously could only be inferred

( ACS Nano 19 38910 ) . “ These insights are essential

for optimising foliar fertilisation strategies and , in the

longer term , reducing fertiliser losses and their associated

environmental impacts says DTU co author Rajmund

Mokso Similar ESRF nano imaging approaches

are being pursued by ERC grantee Astrid Avellan at

CNRS in Toulouse aimed at designing more efficient

nano fertilisers

Now with the EBS upgrade and instrumental

developments at the ESRF we expect to shine more light

on the performance of novel fertilisation strategies says

Castillo Michel High spatial and spectral resolution

X ray techniques could lead to improvements in crop

productivity worldwide



Jon Cartwright

FIGURE 2 : TRACKING FERTILISER NANOPARTICLES INSIDE A LIVING LEAF

R A J M U N D M O K S O

X - ray nano - holotomography images show manganese - oxide ( MnO ₂ ) fertiliser nanoparticles inside a living barley leaf . The 2D virtual slice ( A )

reveals mesophyll cells , chloroplasts and aggregated nanoparticles within the cell wall matrix , while the 3D rendering ( B ) shows plant tissue in

green and nanoparticle clusters highlighted in red .

25 µ m