Hay ventilation
A hay ventilation is a system in which by a fan via ducts and grates air for cooling in the hay is promoted or in a Heuturm. This is to prevent the hay from heating up, which can lead to spoilage or, in the worst case, to hay self-ignition . Most of the hay vents were built in the 1960s. Since then, its importance has steadily decreased , except for farms that are not allowed to feed silage . It is not to be confused with the hay blower , which is only used to store loose hay or straw.
It is still important in companies that produce hay milk . Corresponding investments are funded in some German federal states. Ventilation with heated air means that costs of 0.3 to 0.7 cents per kilogram of hay are expected.
purpose
The primary aim of the hay ventilation is to prevent the hay from spoiling due to mold growth. In addition, this avoids the spontaneous ignition of hay , which can occur when storing hay with still high residual moisture. In the haystack, the hay lies on a mostly wooden grate about 40 cm above the ground, with the fan pushing fresh air through the grate upwards through the haystack and thereby dissipating heat, moisture and fermentation gases. Such a device in a haystack is also called a hay box.
Modern haysticks have hay probes , which allow the ventilation of the hive to be automatically regulated and made more efficient. In addition, the permanent temperature monitoring enables automatic alarming.
In many countries, farmers are legally obliged to monitor their haysticks, which is usually done using hand probes. Disregard resulting in fire can lead to criminal penalties.
By moving into a hay box early on, the feed (hay) retains important nutrients that are otherwise lost due to the loss of crumbs or drying out (due to the sun). This means that there is less reduction in milk yield during the winter feeding days for the cows. Losses due to a harvest in poor weather conditions are reduced by ventilation.
Round bale ventilation
A ventilation module enables the simultaneous drying or dewatering of eight round bales, which are arranged on two rows one above the other. It consists of a lower and an upper ventilation chamber, which are connected by a pipe for the passage of air in the middle. The four lower round bales are ventilated from below, the four upper ones from above. The air goes through the bale without a specific direction, i.e. both axially and radially, so that the forage hay is dried evenly and ventilation is effective.
Additional heating
Depending on the weather and the time of year, the fresh air drawn in is additionally preheated by an oil or gas heater, which is intended to force the drying of the hay. Additional heating systems are often mobile and transportable, they are connected to the permanently installed hay ventilation via flexible connecting pipes.
But there is also additional heating by means of wood chip heating and heat exchangers.
One of the most elegant solutions is the means of roof extraction. The hot air is extracted from below the roof and fed through a collecting duct under the ventilation grille.
Web links
- Research and innovation project efficient hay ventilation of the Bavarian State Ministry for Food, Agriculture and Forests (StMELF)
- Hay drying from A to Z - Chamber of Agriculture (accessed March 20, 2020)
- Guidelines for hay ventilation systems (accessed March 20, 2020)
- Considerations when planning box drying (accessed March 20, 2020)
- Seven tips for better dry forage (accessed March 20, 2020)
Individual evidence
- ↑ Report in Schweizer Landtechnik in June / July 2007 ( memento from December 13, 2013 in the Internet Archive ), accessed on December 9, 2013
- ↑ Top Agrar : Make hay milk now? , pdf, accessed on May 4, 2018