Loading Bales

Agriculture continues to rank as one of the most hazardous industries in the U.S. according to the National Safety Council. In 1995 there were six times as many fatalities per 100,000 workers involved in agriculture as compared to other industries. There were 140,000 disabling injuries on U.S. farms in 1995. It is very appropriate to discuss the safety issues involved in haymaking an ensiling.

Chopping Corn

Since haymaking and ensiling involve machinery and are labor intensive, accidents must be considered. Haymaking, in one sense, is a race between forage manager and the weather. As a result, workers may feel pressured and sideset safety precautions. Ensiling also requires harvesting, transport, and storage so machinery safety should be carefully planned. Farm machinery has moving parts which can easily snag clothing and entangle people into the machinery. Utilize shields and guards provided. 55% of all farm fatalities involved tractors overturning. Wearing a seatbelt and equipping tractors with rollover protective structures will reduce this statistic. Harvesting hay or silage on slopes or near ditches, and packing bunker silos are areas of common problems.

If hay is baled too wet the moisture and compaction combine to give off heat and spontaneous combustion is possible. The smaller, more loose bales can tolerate a higher moisture content (~22%), but larger bales should have lower moisture levels (~13-15%) to avoid fire.

Both hay and silage by their nature and design involved confined and enclosed spaces. Confined space indicates a limited means of escape. Careful planning must be taken when storing large bales. Confined areas mean that a person could be engulfed in cavities of large quantities of farm substances.

Ensiling, because it requires a chemical fermentation, has three specific types of danger. There are opportunities for flammable or explosive situations, asphyxiation (when gases displace oxygen), and toxic poisoning. When silage is put into the silo, fermentation begins. Once forage is ensiled, managers should allow the fermentation process to run its course. Re-entering a closed silo should be carefully considered. Nitrogen dioxide, and carbon dioxide should be monitored and oxygen levels should be checked because oxygen depletion is common. Nitrogen dioxide results from plant nitrates releasing nitric oxide which combines with oxygen, and has a bleach-like odor. It may be visible as brown, red, or yellow fumes. It travels low and will often settle low. Normally, nitrogen dioxide gas forms soon filling the silo, continue intensely for 2-3 days and taper off in about two weeks. Unless there is proper ventiliation, though, it may remain in the silo for up to three weeks. Nitrogen dioxide turns to nitric acid when it contacts moisture, so severe damage can be done in the throat and lungs after contact.

Carbon dioxide is a colorless, tasteless, and odorless gas so gives little warning of its danger. Sealed silos are designed to limit oxygen so carbon dioxide buildup should be expected. Reducing the level of carbon dioxide can be done by following fertilizer reuqirements for the crop to be ensiled and considering whether the crop has experienced drought conditions before harvest since extra nitrate absorption may occur. Weeds within the forage can add to the nitrate levels and plants will take up more nitrates after hail or frost damage. Leaving a long stubble during swathing leaves behind much of the nitrates in the lower stem.

Before entering or filling a silo follow these precautions:

  • Silage blower should run for about 20 minutes before entry and continue throughout the process.
  • Monitor gases and oxygen level.
  • Wear self-contained breathing apparatus.
  • Only enter with someone outside trained in what to do if a rescue is needed. Rescue does not mean the buddy also enters the silo.
  • Wear a full-body harness with life line connections.
  • Open ventilation so that heavier gases can be wisely directed.
  • Ventilate nearby rooms and protect livestock from gases.
  • Lock dangerous rooms and post warnings to prevent others from unsafe areas and situations.