With an early maize harvest looking likely on some farms, many units could benefit from planting grass after maize and using that extra forage to replenish the forage larder.
Last year’s early maize harvest saw many farmers planting grass after maize, and this could be an approach that is repeatable this year.
In 2018 Westerwolds and Italian rye-grasses helped some farmers bridge the forage gap after a summer of drought conditions, and Graham Ragg, an agronomist with Mole Valley Farmers suggests this need not be a one-off an could be an ongoing strategy.
Mr Ragg says: “The biggest investment on-farm is land. If you can get more return per acre by growing two crops a year, it has got to improve returns from your land.
Mr Ragg believes leaving maize stubbles over winter not only represents lost production, but also creates an unacceptable environmental risk.
“Maize often gets blamed for surface run-off. It is not best practice to leave stubbles and it is going to become less acceptable to leave soils bare over winter,” he says.
This year’s favourable growing conditions also represent a huge opportunity to build up the forage larder.
“Living on a tightrope is not a good idea as it is going to cost you if you run out of forage and we cannot guarantee again that we are going to have such a favourable time,” says Mr Ragg.
“Dairy farmers should have two months extra forage up their sleeve. If we are going to get dry summers and late springs, you need that buffer.”
Drilling grass immediately after maize harvest should provide an early spring silage cut before maize drilling. It may also be possible to graze it over winter.
In terms of variety choice, Italian rye-grasses provide greater flexibility as they can survive for two to three years. If left, rather than being replanted with maize, you could expect about five cuts a year off these leys.
With fertiliser applied between cuts, they could yield about 61-74 tonnes per hectares (25-30t/acre) fresh weight over the growing season.
“With Westerwolds you have to put maize in as they will not last. However they give a 10 per cent higher yield and grow at 1-2degC lower temperatures versus Italian rye-grass,” explains Mr Ragg.
“Westerwolds are also less winter hardy, so up-country, I would suggest using Italian rye-grasses. Ultimately there is a variety that is right for all farm situations, so all farmers have the potential to adopt this approach and maximise their farm’s potential.”
BENEFITS OF GRASS AFTER MAIZE
• Prevents surface run-off over winter
• Boosts production - expect yields of 7-10t fresh weight/acre from a first cut at around 11.5-12 metabolisable energy and 16 per cent crude protein (depending on location)
• A winter grazing may be possible, followed by one to two silage cuts (depending on location)
• Expect a 3:1 return on investment - if you produce 7-10t/acre fresh weight of silage at £30/t, that is a £300/acre value at the top end. It will cost about £70-£80 per acre for the seed, drilling and slug pellets
How to do it
• Direct drill grass into maize stubbles immediately after maize harvest
• If the field is clean of weeds, consider an application of slug pellets
• On weedy field, glyphosate may be needed to clean up the field prior to drilling
• To get good establishment, use a seed rate of 12.5kg/acre, increasing to 15kg/acre when drilling later
• Better establishment will be achieved when grass is drilled earlier
Apply straight nitrogen at about 84kg/ha in early spring (start of February)