Maize Watch: Attention to minimising losses needed at clamping

With maize being cut or close to harvest in many parts of the country, growers need to focus on the clamp, believes Neil Groom, technical director at Grainseed.

Minimising clamp losses will be even more important this year, with low forage stocks due to the summer drought.

“We have foragers with high chopping capacities enabling large areas to be quickly cleared but it’s important to load the clamp well to get efficient fermentation and reduce losses,” said Mr Groom.

See also: Poor growing conditions could see reduced maize starch yield and lodging

Clamping best practice

“The MGA [Maize Growers Association] rule of thumb is that you need 25% of the crop weight arriving in the clamp every hour in steel weight rolling the clamp.

“So, if every 10 minutes there is a 15-tonne trailer arriving, that’s 90 tonnes of maize an hour and so you need around 25 tonnes of tractors rolling the clamp – that’s a buckrake and an extra rolling tractor,” Mr Groom advised.

“With larger clamps we have seen the use of compactor rings, piste bashers and even vibrating rollers consolidating the silage. All of these require shallow layers of maize to be pushed up by the buckrake because you cannot compact deeper than 6in per layer.”

Mr Groom has advised farmers to:

  • Pay particular attention to the shoulders of the clamp and the clamp walls, which should always be lined with a plastic sheet to prevent clamp acids eating into the concrete
  • Keep rolling the top of the clamp once it is filled to get really good consolidation in the top metre of the clamp where heating can occur
  • Sheet with an oxygen barrier film, a bird net and weight down with gravel bags or mats to keep the sheet in close contact with the silage
  • Keep the clamp sealed for four-six weeks to ensure perfect fermentation and allow time for the starch grains to soften ensuring cows can digest all the starch in the rumen during feeding
  • If you wish to open the clamp sooner, consider making a small clamp for feeding first or using a modern silage additive which can remove oxygen from the clamp and ensure a faster fermentation

Farmers Weekly sampling sites

Sampling for Farmers Weekly in Harleston, Norfolk, Toby Tibbenham has predicted he will be harvesting next week.

“Last week’s dry matter surprised us and we have had a careful look around all our crops this week,” said Mr Tibbenham.

“I want some really high energy maize for next winter’s ration and so I think cutting next week will be perfect and this will allow us to get the fields cultivated and drilled into wheat in good conditions.”

The crops on Farmers Weekly sampling sites in Devon, Carmarthenshire and Derbyshire are also maturing nicely (see below).

If good weather continues, maize will be ready to chop in September in most areas of the country, predicted Mr Groom.

Maturity on six sampling sites

Site Drill date Height above sea level (m) Crop dry matter 29 August Increase from last week
Petworth, Sussex 2 May 50 Harvested  
Harleston, Norfolk 6 May 30 31.5 +0.6
Crediton, Devon 1 May 118 29.4 +3.3
Ticknall, Derbyshire 4 May 67 28.7 +2.0
Llandeilo, Carmarthenshire* 6 May 32 26.3 +3.6
SRUC, Dumfries, Scotland PLASTIC 30 April 45 21.2 +0.9
 * Variety Es Picker, all other sites are Es Ballade. Variety under plastic Es Marco