Farmers invited to learn results of United Utilities' innovative under-sowing maize trial

Cheshire farmers have been invited to learn the final results of the innovative under-sowing maize trial that United Utilities has been running at Higher Barn Farm in Willington, Cheshire.

The water company will reveal the results of the trial at a special event held: 


Wednesday 10th April, 2019 


10:00am to 1:00pm

Location: Higher Barn Farm, signposted off Tirley Lane, Willington, CW60JT


The trial has tested the viability of under-sowing maize with grass and its effects on nitrate loss, soil erosion, surface runoff, ground water quality and crop yields. It was conducted within a nitrate-sensitive water catchment zone near Delamere between April 2018 and April 2019, was funded by United Utilities and run by land and property specialist, Rostons, together with agricultural consultant, Paul Sweeney Agronomy. 

The under-sowing maize trial was run on 30 plots over 90 acres and consisted of 10 individual plot treatments featuring different methods for growing forage maize featuring:

  • The technique of under-sowing the crop with different grass species at different times
  • Establishing ground-cover ‘catch crops’ post-harvest

United Utilities’ Southern Catchment Manager, Dr Kate Snow, said: “This will be the final demonstration day when we’ll present all our results on crop yield and water quality. We’re inviting farmers with land in its Cheshire borehole catchment water safeguard zone to come along and see for themselves which options have worked best.

“We’ve trialled different methods and timings using different types of farm machinery at different times so farmers can see what would fit into their own individual farms.

“In addition to nitrate loss, other environmental and water quality issues are associated with late harvesting of maize into the autumn. The bare soil, left exposed over winter, can lead to soil erosion, phosphorus loss and soil sediment loss into local rivers and streams.”

For more information please contact Clare Vincent at the United Utilities Press Office on 0345 072 0822 or 07904 112484.

Notes for editors

About the trial

This trial seeks to evidence the nitrate losses from maize growing combined with the potential economic benefits that growing the crop in an environmentally sustainable way can bring due to reduced fertiliser bills and improved soil health. It will test the principle of under-sowing maize with grass – the technique of establishing a ‘nurse crop’ of grass during the maize establishment period which is considered to be a valuable method for providing a post-harvest ‘mop’ to reduce nitrate loss through the soil profile. This technique should have additional benefits over reduced nitrate loss in terms of reduced soil erosion and phosphorus loss. The trials aims include:

  • To capture relevant data on nitrate loss from different methods of growing forage maize
  • To demonstrate the practical effects of new growing methods, principally under-sowing with grass, on both the commercial viability of forage maize and the environmental benefit of reduced nitrate loss
  • To offer insight into the secondary effects and environmental benefits that under-sowing with grass also has on reducing soil erosion, phosphorus loss, soil sediment loss and improving soil health

United Utilities

United Utilities is the UK’s largest listed water company and manages the regulated water and waste water network in North West England - which includes Cumbria, Cheshire, Greater Manchester, Lancashire and Merseyside with a combined population of nearly seven million. United Utilities' headquarters are in Warrington. Its shares are listed on the London Stock Exchange and the FTSE 100 Index.


Rostons is an independent firm of chartered surveyors and agricultural valuers with particular expertise in land and property and specialising in all rural matters.

Paul Sweeney Agronomy Ltd

Paul Sweeney Agronomy is an independent agronomist working directly for farmers consulting on agricultural and technical issues.