GrassCheckGB is a grass monitoring project involving 50 dairy, beef and sheep farms.

Growth and quality data will be published weekly throughout the growing season.

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The 2020 season has brought a series of challenges, and among them have been some difficult conditions for grassland management on farms across GB. Farmers were faced with weather extremes from wet to dry and back again over the 2020 grazing season, and data gathered through the GrassCheckGB project shows just how the weather conditions have impacted grass growth rates throughout the season. GrassCheckGB involves a network of 50 farms monitoring grass growth rates across the country, is run by CIEL (Centre for Innovation Excellence in Livestock), AFBI and Rothamsted Research and is sponsored by AHDB Beef & Lamb, HCC, QMS, Datamars, Germinal, Waitrose, Handley Enterprises and Sciantec.

At the close of the projects second year in October 2020, GrassCheckGB farms had produced an average yield of 9.5 t DM/ha since the beginning of March, and whilst this is still a respectable volume compared to average industry figures (estimated to be 4.7-7.5 t DM/ha), it is over 1.4 t DM/ha below the average yields recorded across these same farms in 2019 of 11 t DM/ha.

A number of factors contributed to the lower grass yields recorded in 2020. The wettest February on record saw the Met Office report 237% of average rainfall across the UK. This led to significant flooding and saturated soil conditions which slowed or even stopped grass growth for a period at the start of the season. Moving into March conditions began to dry up, and GrassCheckGB farms recoded on average just 54% of typical rainfall, and this fell to8.7% in April. With low rainfall continuing into May (just 42.6% of typical rainfall was measured on GrassCheckGB farms) and the first week of June a significant soil moisture deficit had developed across the country. This soil moisture deficit was evident in data recorded from soil moisture probes planted on all the GrassCheckGB farms, and at this time grass growth rates fell to only 60% of expected values for the peak of the grass growing season. However, above average sunshine hours were recorded by the Met Office this spring (144% of typical values) which did help to drive excellent grass quality, with average weekly ME values ranging from 11.7-12.2 MJ/kg DM, with high DM values of 20-27% in April-June 2020. Grass quality remained good throughout the season, with ME averaging 11.7 MJ/kg DM and an overall average for DM of 20.9%.

Measuring paddocks regularly to monitor grass growth and having flexibility in your grazing system to adapt to changing conditions throughout the season is key to making the best use of grass, particularly in more difficult years.

Speaking about her experience of the GrassCheckGB project, Amy Barnes, a GrassCheckGB sheep farmer from Yorkshire, says “Measuring grass and using AgriNet has meant that we are able to graze more efficiently, with better regrowth. This year it was particularly important at spring time during the hot period when we were short on grass and the ewes were lambing. By setting up a rotation, grass utilisation was maximised thus reducing the need for bought in feed, without compromising ewe body condition or milkiness".

This is echoed by fellow GrassCheckGB farmer Tom Stobart, who runs a beef and sheep enterprise with his brother Jimmy in Cumbria. “Measuring grass weekly for GrassCheckGB has really improved my knowledge of how much grass we have on the platform, and that helps us make informed decisions based on the actual data. This particularly helped in mid-spring as we saw soils getting very dry in the drought – silage ground was brought back into the grazing platform for a time to keep enough grass in front of the cattle to keep them growing well”.

Weather conditions were much more typical in the summer and early autumn months, but for most farms the grass growth rates seen were not enough to make up for the lower spring yields recorded. October then saw the grazing season end for many in similar conditions to how it began – wet, with Storms Alex, Barbara and Aiden bringing some very heavy rainfall. Data from the Met Office shows October 2020 recording 142% of average rainfall. Because of the wet weather and ground conditions some stock were housed earlier this year, but where soils allowed many farms were able to utilise the late season grass growth, some with lighter stock or on-off grazing strategies, as grass growth rates continued to average >20 kg DM/ha/d throughout October.

GrassCheckGB will be returning with regular weekly updates on grass growing conditions across the country in spring 2021, and you can find out more at or by following @grasscheckgb on twitter or GrassCheck_GB on Facebook.