Tips for managing spring grass in a challenging year

Now’s the time to make key decisions around grazing and silage management in order to mitigate the adverse effects of a late turnout and delayed nutrient applications.

With February the warmest on record across England and Wales,* and most regions facing prolonged rain, many farmers have been unable to graze cows or apply sufficient slurry and fertiliser. At the same time, forage stocks are dwindling and grass covers are climbing.

Graham Ragg, Senior Agronomist for Mole Valley Farmers’ Grassland & Forage Agronomy Team says the situation is “getting serious.” He’s seen grass covers of upwards of 30cm (12 inches), when fields should ideally be grazed at around 10cm (4 inches). He stresses that failure to manage these swards could have big implications later in the season.

“If high grass covers aren’t managed now, there’s a risk they will ‘get away’ from cows, leading to stemmy, low quality leys and high wastage. This will ultimately reduce forage quality, regrowth and milk yields,” he explains.

To help safeguard grass quality and performance, Graham suggests the following:

1. Cut more acres for first cut silage and try to cut early
Can you take first cut 1-2 weeks earlier than normal and increase the area harvested? By cutting earlier the sward will be greener at the bottom and quicker to regrow. Cutting a higher acreage will enable cows to be focused on a smaller grazing area at turnout, allowing more effective management of higher covers. It will also maximise the yield of the best quality silage cut and replenish forage stores. With potential for soil contamination high, and sugars likely to be low, ensuring a good fermentation is critical. Using a quality silage additive will help optimise forage quality.

Apply fertiliser immediately post harvest. You will see a 2% yield drop on second cut for every day you delay applying fertiliser after first cut.

2. Consider on off grazing
To make the most of spring grass, but to avoid damaging wet ground, consider ‘on-off’ grazing on the driest paddocks and turn cows out for just a few hours. According to Teagasc, cows can achieve 90% of their daily grass intake in the 2-3 hours after each milking compared to cows out full-time.

3. Think about fertiliser timings
Excess nitrogen in grass will result in poor silage fermentation so it’s important not to apply fertiliser too close to cutting. Choose your target cutting date and work backwards to when you can apply fertiliser, allowing for uptake of 2.5kg of nitrogen per hectare per day (two units of nitrogen per day). Generally, if first cut is taken in May-June, you can afford to apply fertiliser at the normal time. If you’re aiming to cut at the end of April, it may be necessary to reduce application rates, based on calculations.

4. Don’t reduce fertiliser use from the end of April to June
Grass responds twice as well to fertiliser applied in April and May, compared to July and August, so if conditions allow, it pays to apply during this period. As forage stocks are depleted on many farms, it also makes sense to replenish pits and build reserves.

5. Think about slurry timings
Avoid applying slurry if you’re planning on taking first cut within 6-8 weeks as this will increase the risk of leaf contamination. This could lead to poor fermentation in the clamp and potentially be detrimental to livestock health. All slurry applications should be carried out according to a Nutrient Management Plan and to crop requirements.

For more information and support, please contact the Mole Valley Farmers Grassland & Forage Agronomy Team on 01769 576232 or email [email protected]