“Nutrification” sounds like a positive word: adding nutrients to aid growth – that’s surely a good thing?  Not in this instance. 

When we’re talking about river nutrification, The Environment Agency says:

“This is when there is too much nutrient in rivers, lakes/reservoirs, estuaries or the sea, causing excessive growth of algae and plants. This adversely affects the quality of the water and our uses of it, as well as damaging the local ecology.”

(Source: Phosphorus and Freshwater Eutrophication Pressure Narrative, page 3.  Published October 2019).

River Nutrification Aka “Eutrophication”

River nutrification, more accurately known as river “eutrophication”, sets in motion a death spiral in water courses. 

Nitrogen and phosphorous over-enrich water, allowing algae to flourish.  The algae form a blanket across the surface, blocking light penetration, which inhibits photosynthesising organisms ie. plants that are food sources for small fish and insects.  These fish and insects, in turn, are part of the food chain for other fauna. 

It doesn’t end there: eventually the algae dies, and its decomposition uses up oxygen which leaves water hypoxic and creates a lifeless aquatic environment.

River Eutrophication & Fertilisers

To a degree, eutrophication is a natural process, however, human activity has tipped the delicate balance too far. 

Fertilisers, rich in nitrogen and phosphorous, are among the biggest culprits: field run-off into rivers and streams pollutes the eco-system. 

Nitrogen is the most common fertiliser nutrient with over one million metric tons consumed in 2020, according to Statista Research Department (April 2023).

Liquid fertilisers can help ameliorate the nutrification of water courses, and more and more farmers are turning to them. 

How do Liquid Fertilisers Reduce River Eutrophication? 

In March 2022 Farming UK reported:

“Liquid fertilisers are the fastest growing area of the fertiliser industry, as farmers recognise the economic and environmental benefits over solid products, including reductions in emissions.  With fertiliser prices having shot up by 350% in 12 months, farmers are being incentivised to be more accurate about the placement of fertilisers and the use of liquid fertilisers helps with that.”

A key benefit of liquid fertiliser is that nitrogen loss is lower than with solid fertilisers: liquid fertiliser moves quickly through the soil resulting in more product nutrient availability to crops, especially in dry conditions.

Targeted sprayer application of liquid fertiliser allows for 100% field coverage, right up to field margins. This helps to ensure that crops get the nutrients they need when they need them, for maximum yield potential; unlike many granular formulations, water-soluble liquid fertiliser allows the application of nitrogen and nutrients evenly and consistently.  It can be combined with other nutritional and protective products and applied in one-pass, saving time, fuel and labour costs and emissions.

There is also less plastic waste, as liquid fertilisers is stored in re-usable tanks.  And it takes up less space than solid fertiliser, which is a major plus for farmers with limited storage. 

The proper application of liquid fertiliser to the crop edge helps to protect the environment and field margins under management schemes.  This applies particularly to farmers working within Nitrate Vulnerable Zones, where mandatory rules - set out in Action Programmes - must be enforced to reduce nitrate loss from agricultural land and to protect human health and resources from water pollution.  For example, farmers must assess the risk of run-off before spreading, and the risk of nitrogen getting into surface water, before spreading any fertilisers or organic manures.  Manufactured fertilisers or organic manures must not be spread if a field is either waterlogged, flooded, or covered in snow or frozen for more than 12 hours in the previous 24 hours.

There are pros and cons for liquid fertilisers, but the trend is away from solid compounds and liquid applications can play a part in reducing eutrophication of our precious water courses.