Now is the time to start planning for autumn reseeds to make sure they have the best chance of success. Farmers Guardian reports.
Regularly renewing pastures is important to maximise productivity and maintain feed quality, according to Dr Liz Genever, AHDB Beef and Lamb senior scientist.
She says: “Well-managed grass is the most cost-effective feed for ruminants. Research has shown us the greater proportion of the farm reseeded each year means more grass is grown and utilised, resulting in increased farm profit.”
Reseeding should improve pasture yield and quality, which means it is possible to get more from grass grown, reducing bought-in feed costs.
It also provides an opportunity to improve grass genetics and introduce new varieties which suit the needs of the farm, increasing productivity, durability and disease resistance.
Dr Genever says: “Research indicates pastures with a low proportion of perennial rye-grass cost beef producers up to £250/hectare per year due to a loss of grass dry matter (DM) production and reduced nitrogen use efficiency during the growing season.
“Reseeding costs about £600/ha, so the increased profitability of the reseeded pasture would cover the reseeding cost in just more than two years. This means reseeding is one of the most cost-effective on-farm investments.”
The best way to identify swards which might benefit from reseeding is to measure yield from each field regularly.
After assessing swards, if two of the following are present, it is worth considering reseeding:
Autumn is a good time to reseed, because there will be minimal impact on yield losses compared to spring reseeds, where peak growth is lost. Seedbeds also have time to settle over winter, allowing good structure to form.
AHDB conducted a reseeding survey in 2016 and about 66 per cent of respondents reseeded in autumn, between August and October.
Before reseeding, make sure the field drainage system is working and carry out soil tests to make sure soil has the right nutrients. It is also important to assess soil structure.
It is important to use the right species of grass for the farm situation by using the Recommended Grass and Clover Lists (RGCL).
Dr Genever says: “The lists are drawn up after rigorous trials and testing which focus on attributes such as yield, persistency, quality and disease resistance.
“Data from these independent trials is then evaluated and assessed by a panel of experts, based on overall ability to contribute to grassland farming. As new varieties come on to the list, older, poorer performing species are removed.”
Some varieties perform better when grazed rather than when cut for silage and vice-versa, so it is important to consider what the sward will be used for. The RGCL provides data for all varieties on both silage and grazing management.
Dr Genever says: “Once you know how the sward is going to be used and have identified suitable varieties, you can consider traits which are important to the farm situation, for example, growth, ground cover, winter hardiness and disease resistance.”
Grass leys are often sown as mixtures, as this minimises the risk of a crop seed failing, ensures quality throughout the grazing season and means a balance of desirable traits can be achieved.
They are often comprised of diploid and tetraploid rye-grasses, with a small amount of other species, such as timothy or clover. It is important to consider the heading date of varieties within a mix.
Clovers provide a good source of protein when grazed or conserved. They have high digestibility and are a good option to include within a reseed. Clovers also fix nitrogen, which means less artificial nitrogen is required.
Dr Genever says: “The choice of whether to include red or white clover depends on what the sward will be used for.
“White clover is longer lasting, particularly under grazing systems, as its stolon stores nutrients, enabling it to withstand grazing.
“Red clover is short-lived, only lasting two to four years. It is higher yielding than white, but is less persistent and is generally used in cutting leys.”
To assist with decisions, a recommended list is available for white clover, with a descriptive list available for red clover. Both can be found at britishgrassland.com/rgcl.
An RGCL webinar, which talks through how to choose varieties, is available on the Beef and Lamb TV YouTube channel.
An interactive tool to help choose varieties from the RGCL is available at dairy.ahdb.org.uk/technical-information/grassland-management
The grassland reseeding guide is available at beefandlamb.ahdb.org.uk/returns