Silage additive loss due to inadequate delivery
“Typically, products are applied above the pick-up on the ‘air side’ of the grass, or at the base of the chute after the accelerator on self-propelled forage harvesters, but this means they are highly vulnerable to drift, especially in windy conditions,” said Andy Strzelecki, technical director at the UK forage specialist, Kelvin Cave Ltd.
“Further wastage has been shown to occur when flat-fan nozzles are used to spray the additive, and these would be better replaced with solid-jet sprays,” he said.
The findings come from trials undertaken by Matts Nysand and Antti Suokannas of MTT Agrifood Research, the research institute of the Agriculture Ministry in Finland.
“Our observations in the UK are very similar to those found in Finland, and we would echo the report’s conclusions,” says Mr Strzelecki.
He recommended that with a loader wagon, ideally half the additive should be dosed from above, and half from below on the pick-up, and solid jets used instead of fans, which will reduce additive losses and give a better distribution.
In a trailed harvester, the best place of application is in the lower part of the chute, and in a self-propelled harvester, the best place of application is inside the inlet channel before the knife rotor or accelerator, said Mr Strzelecki. He said dosing equipment in the UK is often poorly calibrated or simply inadequate for the job, partly because of the huge range of quantities expected to be delivered — from as little as 20ml to as much as five litres per tonne of crop.
