FROM THE FARM REPORT: HARVESTING HAYLAGE ON TIME IS CRUCIAL…BUT NOT THIS TIME OF YEAR!

As a forage agronomist I usually find myself preaching about how short the optimal harvest window is for hay crop forages. This is because, for most of the season, the optimal window for maximizing haylage yield and quality only lasts for a week or two. If a farm is forced to harvest its first cut outside of this window (due to weather, equipment failure, or prioritizing something else), they are likely to end up with either an empty bunk or a bunk full of heifer feed. This time, however, I have chosen to focus on fall haylage harvests… which don’t act at all like spring or summer harvests.

Grasses and legumes decline in forage quality as they mature. This is due to a higher proportion of fiber (mostly stem tissue) and a decrease in its quality. This pattern holds true at all times of the growing season in the absence of environmental extremes. It does not, however, always occur at the same rate. This is what sets late summer/fall harvests apart. Though the weather can be excellent in the fall for grass growth, we don’t tend to see the decline in forage quality occur as quickly as the end of the season nears. Part of this is simply due to lower temperatures, but some of it is also likely due to physiological changes in the plant as it prepares to go dormant for the winter.

But how long can the haylage harvest window actually be in the fall? I suspect the answer is “it depends” on weather conditions, crop species, etc. However, we can get some sense of this by examining stockpiling research for late season grazing. I found one such study that reported little to no decline in tall fescue digestibility from September through early November. That’s a harvest window of over a month for forage that re-grew from a mid-August harvest!

The whole idea of stockpiling for grazing is built off the assumption that forage quality can be maintained at an adequate level for a significant period at the end of the season. Tall fescue seems to be the best for this, but other grasses and some legumes can be quite good as well. Quality can be maintained until sub-freezing temperatures and wind starts to cause significant tissue damage.

This is good news for forage producers – even those who don’t graze. It means that when your haylage and corn are ready to be cut at the same time in September the haylage can wait. Waiting may also improve winter survival if you wait to harvest right before a major cold snap that shuts down fall growth.

Some farms choose to not harvest fall growth at all. While this might help mitigate injury due to ice sheeting, excessive biomass left on a field can also smother the plants and dilute forage quality in the spring. At Miner Institute, we harvest our fall growth if the conditions allow. The short days and heavy dew/frost can make it difficult to wilt forage, but the higher wind speed and moderate biomass can make it doable.

— Allen Wilder

wilder@whminer.com