2017 brought huge variations in weather patterns between the east and the west. Many parts of the West and Southwest experienced drought conditions throughout the growing season. Flooding was an issue, with hurricanes hitting Texas and the Gulf Coast as well as the East Coast. Much of the Central Plains, Northeast and Midwest regions were punctuated with above average rainfall.
“These extreme weather conditions can quickly change the quality potential of forage,” said Pascal Drouin, microbiologist with Lallemand Animal Nutrition’s Silage Center of Excellence at the Miner Institute in New York. “When we have dry weather, the problem is when to harvest silage and how fast because this will affect crop regrowth.”
If a dry spell hits after cutting a low-maturity forage, the regrowth is poor, and it’s difficult to anchor the overall yield of the field. Waiting for a higher yield during some of the later cuts may lessen quality, but it is less stressful in relation to the fermentation quality.
“Ensiling forage of high dry matter (DM) will lead to more stressful conditions for the lactic acid bacteria, but they are selected for their competitiveness,” Drouin said. “When high DM silage are opened, the risk of having fungal contamination is higher since the fermentation was less efficient.”
In the east, the issue was very different due to higher levels of moisture. When the humidity is too high, it’s difficult for the microorganisms to produce enough lactic acid to overcome the amount of water in the silage. Since there is less sugar available for the fermentation, the acidification potential is negatively influenced.
Measures to Counter Erratic Weather
In dry conditions, rely on best management practices when harvesting and ensiling.
“In wetter, more humid regions, we’ve tended to have a longer spring that also has a warm spell in the middle, so the forage starts to grow faster, then growth slows down, and harvest arrives at the same time as the planting of other fields,” Drouin said. “Growers should start to harvest earlier even if the first cut is not quite ready for harvest. When that ideal time arrives, we tend to have wetter spells and are not able to get in the field.”
In both scenarios, use a research-proven, reputable, bacterial inoculant to help activate the fermentation process and create the best quality silage.
“Inoculants ensure the fermentation process starts as quickly as possible,” Drouin said. “For wetter silage, inoculating with efficient lactic bacteria ensure that enough acidity is produced by the fermentation process within the first 24 to 48 hours after ensiling to control spoiling microflora.”
With drier forage, the material can’t be packed as tightly, allowing more oxygen and porosity of silage. Treating with a lactic acid bacteria inoculant helps protect the silage against this issue. When the porosity is higher, a lactic acid inoculant’s strain improves aerobic stability because it has antifungal properties that negatively impact the growth of yeast and mold, which degrade silage quality.
Proactive Planning for 2018
“Trust the weather report. Weather teams get a bad rap, but they are quite good about predicting conditions seven to 10 days in advance,” Drouin said. “Closely watch the forecast at harvest. When there’s a three-day window of good weather, and you’re doing something out in the field, but you know your forage will be ready in a week, you should take that three-day window and harvest a bit earlier than you planned. My advice is to be ready and don't wait. When you see a good opportunity to harvest and ensile, take it – even if you have to go a little early.”
Based on research, Drouin advises growers to always use an inoculant with their silage.
“Adding an inoculant changes the microbial dynamic in the silage and improves the quality even when the harvesting conditions are good, but when the harvesting conditions are poor, an inoculant will significantly improve the quality of the silage,” he concluded.