Nitrate

What is Nitrate?

Nitrate is a chemical found in agricultural fertiliser. Fertilisers are applied to land to encourage crops to grow faster and bigger so that crop yields are increased. Fertilisers first have to dissolve in water before they can be absorbed by plants.

Why is it a problem?

Not all of what’s applied to the land is used by plants. This remainder can leach into the groundwater or run off into watercourses. It is important to protect drinking water sources from nitrate pollution to prevent the need for additional expensive treatment.

Our approach

We’re working on a Nitrate Mitigation Trials Project in partnership with farmers and other environmental organisations. This projects aims to:

  • Reduce nitrate impact on groundwater and rivers by identifying ‘at risk’ or vulnerable areas for nitrate contamination
  • Improve our understanding of land use and potential sources of nitrate in vulnerable catchments
  • Raising awareness and encouraging best practice

There are two elements to this project, Slow Release Fertiliser and Cover Crops.

Who’s involved?

For the last two years, we’ve teamed up with agricultural experts Agrii and Wessex Water.

What was investigated?

We investigated whether slow release fertilisers leach less nitrate than industry favourite quick release fertilisers.

How was it investigated?

Winter Wheat was drilled and treated with three applications of each fertiliser at the critical growth stages. Data was compiled over 2 years.

What are the results?

Our results over the two years showed that the slow release fertilisers leached less nitrogen than commercial favourites, and with careful management can provide a great alternative to quick release fertilisers at around the same cost per ha/kg/N.

Who’s involved?

For the last two years, we have teamed up with agricultural experts FWAG SE, Kings’ seed suppliers and 6 enthusiastic farmers from around the Thames Valley.

What was investigated?

We’ve investigated what benefits cover crops can simultaneously bring to water quality and farmers.

How was it investigated?

6 varieties were drilled on 6 plots in consecutive years, starting August 2015. Our Farmer Workshops provided the opportunity to see the cover crops growing first hand, listen to expert speakers discuss how cover crops can benefit your soil from earthworms to blackgrass control, and ask any questions.

What are the results?

Our results from the first two years showed that an Environmentally Friendly mix was the best performing variety for establishment, yield and holding nitrogen in the soil over the winter ready for the spring crop.

If you’d like more information on our catchment management projects, please email us at catchment.management@thameswater.co.uk