While the UK has more than 17m ha of managed grassland, much of it is poorly utilised – that's according to Duncan Hendry, a grass seed specialist with Cope Seeds and Grain.

He based that argument on the fact that many grass leys that are not in good condition, are overrun with weed grasses which have little or no nutritional value can have a major impact on milk and meat production costs.

Mr Hendry argued that treating grass like any other arable crop, by selecting the right grass seed products for your farm, and reseeding regularly, could significantly affect the bottom line.

“Making a relatively small investment in your grass can have a major impact on its quality, productivity and utilisation, and a reseeding rate of just 10% is enough to prevent a decline in grass productivity while a 15% rate will start to deliver real gains,” he pointed out.

Mr Hendry told The SF that although a grass ley that had been down for more than five years might look productive and healthy, the ley would not be producing to its full potential as by this time 50% or less of the grass plants would be of the species that were sown. The rest would be made up of indigenous species, such as rough stalked meadow grass, bentgrasses or, Yorkshire fog.

“These species have yields well below that of perennial ryegrass, as well as being of poorer quality and lower digestibility," he said.

“Another important characteristic of these weed grasses is their poor response to nitrogen, whether from organic fertiliser, clover or artificial sources, with rough stalked meadow grass giving a response of 17%, bentgrass 33% and Yorkshire fog 42% to nitrogen compared to ryegrasses,” said Mr Hendry.

This means that a five-year-old ley could only be utilising 65% of nitrogen applied.


Only one year after reseeding, undesirable weed species can account for up to 18% of a sward, but after four years this can double to 38% and after eight years, weeds species can begin to dominate the sward up to 50%.

“On average, an eight-year-old sward will yield approximately 5.5-tonnes of dry matter (DM) per ha, compared to a new sward’s potential yield of 15 tonnes of DM per ha. This means that the farm is missing out on 2/3 of the potential yield, which is a significant figure with a massive impact on profitability,” added Mr Duncan.

“Good quality grazed grassland is the cheapest feed for ruminant livestock and is the base upon which profitable farming is built.”


Currently, only around 2% of UK grassland is being oversown.

He made the point that overseeding was a short- to medium-term option, but did not provide a quick fix. It was, ultimately, an effective method of improving productivity whilst keeping investment costs to a minimum.

“Implemented carefully, overseeding has the potential to improve pasture productivity by between 30 to 40% for between three to four years, depending on field quality," he argued.

“When overseeding, it is crucial to use a mixture designed specifically for this purpose. Any existing productive grasses in the ley already have an established root system and an established leaf canopy to capture light for photosynthesis.

"Any new grass seed that is introduced needs to be able to work with these conditions and overseeding mixtures are blended accordingly,” he concluded.