Q. Should I use a dry granular or liquid forage inoculant?
A. When deciding on the form of inoculant to use, dry granular products may seem easier. However, dry granular inoculants can be less effective than liquid applied.
This is especially the case as crop dry matter (DM) increases. I do not recommend using dry granular inoculants on crops with DM levels above 40% (less than 60% moisture). In drier crops, dry granular products need to draw moisture from the crop to activate. That moisture simply isn’t as available in crops with higher-than-recommended DM.
When comparing stability, dry granular inoculants are just as sensitive to decay as liquid product when exposed to heat, moisture and oxygen. Leaving dry granular product packs open for extended times will expose the product to both moisture and oxygen – possibly causing the levels of viable bacteria in the product to rapidly decline.
It can also be more difficult to store dry granular inoculants under optimal temperature conditions. Small-pack, liquid-applied products can even be kept cool out in the field (for example, in a cooler with ice packs), while dry granular products are more likely to be at ambient temperature during the harvest. Be sure at the very least to keep product out of direct sunlight.
For more information about the viability of dry granular products, this short video goes through some of the best research available: https://youtu.be/UVaoAz0CZR4.
The Silage Dr.