Ash can have a bad connotation among silage producers. There are two main sources of ash in silage production:
1. The plant’s internal ash, which provides minerals like magnesium, calcium and potassium
2. Soil contamination, which is characterized by high concentrations of iron, aluminum and silica
The mineral contributions of ash can be important to animal health and performance. On the other hand, non-mineral ash can harbor fungi and bacteria. In addition, dirt is not a nutrient for animals. As external ash contamination elevates, there is a corresponding drop in relative forage quality.
It’s important to keep the ash content in forages within acceptable ranges: 3% to 5% in corn, 6% to 8% in grasses or 8% to 10% in legumes.
To accurately assess ash content, always obtain a forage analysis. Ash contamination is a particular danger in years where fields have experienced rain, flooding or wind that can cause soil to splash or blow onto leaves or stalks. Some uneven fields are simply more prone to excess ash contamination due to the equipment’s tendency to “scalp” the fields and take on soil during harvest.
To manage soil contamination:
• Avoid harvesting lodged forage
• Raise the cutter bar of a disc mower and use flat knives
• Keep the windrow off the ground
• Keep rake tines from touching the ground
• Minimize moving hay horizontally
• Use a windrow merger
• Store silage on concrete or asphalt
If you’ve already harvested and ensiled the forage, watch for specific smells and visual signs of spoilage – e.g., slime, dark green appearance with a foul smell (clostridial activity). For more information about what to do if you suspect clostridial activity, visit qualitysilage.com.
For additional advice, ask the silage quality experts on Twitter or Facebook.