A closer look at soil-plant interactions and fertilizer impact for turfgrass

Bangor University research investigated how struvite and other phosphorus fertilizers interact with turfgrass roots, soil and microbial communities.

Research at Bangor University investigated how different phosphorus fertilizers affect soil-plant interactions in turfgrass, with particular attention given to struvite.

Struvite is a recycled source of magnesium, ammonium and phosphate recovered from wastewater. ICL uses struvite supplied by Ostara within its Sierrablen Plus Pearl range.

The research aimed to better understand what happens after different forms of phosphorus are applied to the soil, including their effects on phosphorus availability, root growth and soil biology.

Why investigate struvite?

Phosphorus is an essential plant nutrient, but different phosphorus fertilizers behave differently once they are applied to the soil.

Researcher Anna Ray investigated these interactions as part of a Masters by Research project at Bangor University, supervised by Professor Davey Jones and supported by ICL.

A major focus was struvite, a recycled phosphorus fertilizer recovered from wastewater.

Recovering nutrients in this way creates the opportunity to return phosphorus that would otherwise be present in a waste stream back into plant production.

The research compared struvite with other phosphorus sources to better understand how the fertilizer interacts with the soil and turfgrass plant.

Understanding phosphorus in the soil

The research program looked at several stages of the relationship between phosphorus fertilizer, soil and the plant.

This included investigating:

• where applied phosphorus is held within the soil
• how phosphorus moves from different fertilizer sources
• the rate at which struvite dissolves
• phosphorus uptake by the plant
• the effect of localized phosphorus applications on root development

Radio-labelled phosphorus was also used to investigate whether phosphorus remained in soil solution or became sorbed onto soil particles.

Together, these experiments were designed to provide a more detailed understanding of how different phosphorus sources become available to turfgrass.

How fertilizers affect turfgrass roots

Another part of the research examined the relationship between phosphorus fertilizers and root growth.

The objective was to understand whether applying phosphorus in different forms or locations affected the way turfgrass roots developed.

This is important because fertilizer performance cannot be assessed only by the amount of nutrient contained within a product. How that nutrient interacts with the soil and plant also influences its effectiveness.

The research therefore aimed to provide a mechanistic understanding of how different phosphorus fertilizers affect turfgrass and, specifically, how they influence plant-root growth.

Effects on soil microbial communities

The project also investigated how fertilizer applications affect soil biology.

One early experiment assessed microbial activity for seven days following fertilizer application.

Soil microbial communities can provide a biological indicator of conditions within the soil, but the impact of fertilizer applications on those communities had received relatively limited assessment.

The experiment showed that fertilizer applications could affect the microbial community, but that the community was resilient and recovered relatively quickly.

In this experiment, struvite produced a response similar to the water-treated control throughout the assessment period.

Further work within the project was also planned to investigate the effects of different phosphorus fertilizers on arbuscular mycorrhizal fungi and microbial diversity.

Why the research matters

The amount of phosphorus contained within a fertilizer is only part of the picture.

Its form, availability, movement through the soil, interaction with roots and effect on soil biology can all influence how the fertilizer performs.

Research into these mechanisms can therefore help explain differences between phosphorus sources and support more informed fertilizer selection.

The Bangor University project was designed to investigate those interactions rather than simply measure a final turf response.

For ICL, the collaboration also provided an opportunity to better understand the science behind struvite used within the Sierrablen Plus Pearl range and to support clearer communication about how the technology performs.

Connecting research with practical turf management

The project was supported through a Knowledge Economy Skills Scholarship and developed through collaboration between Bangor University and ICL.

The academic research provided the opportunity to investigate fundamental questions about fertilizer-soil-plant interactions, while industry involvement helped ensure the work remained connected to practical fertilizer use.

The wider objective was to improve understanding of how phosphorus fertilizers behave after application and how recycled nutrient sources such as struvite compare with more conventional forms of phosphorus.

Understanding those differences can help inform the development and selection of fertilizers that deliver nutrients effectively while making better use of available resources.