By Zachary Curtis
Corn silage moisture content continues to be critical to harvesting a high-quality and high-yielding forage crop. Extension Educators across Pennsylvania are working with cooperating farms to harvest, chop, dry, and track the moisture content of corn silage fields around the state.
Accumulated Growing Degree Days (GDD): A measure of the accumulated growing degree days counted at this location since planting. Calculated using 86/50-degree cutoffs.
Precipitation Deviation: A measure of this location’s departure from the 10-year precipitation average, calculated by subtracting rainfall from planting to the current date from the 10-year average.
Growing Degree Day (GDD) Deviation: A measure of this location’s departure from the 10-year GDD average, calculated by subtracting GDD accumulation from planting to the current date from the 10-year average.
Table 1. Sampling data collected for this week, including weather data collected from the Bushel Farms platform.
Depending on your local precipitation and growing degree day accumulations, corn silage harvest could arrive sooner than in previous years. Be sure to monitor field conditions and test moisture levels to determine the current moisture level of your corn crop. The average daily dry-down rate for silage is about 0.5% of moisture loss per day, with rates ranging from 0.0 to 1.0% in extreme weather conditions. In our observations, average daily dry-down rates across all locations from this past week are estimated between 0.3 and 0.7%.
Currently, locations across southeastern Pennsylvania are trending both warmer and drier than the 10-year average for locations. Pollination success and disease pressure are variable among locations. Although recent storms have brought welcome rains to many parts of the state, precipitation will not affect fields that were poorly pollinated or suffered serious drought stress earlier in the season. If cool weather conditions persist, daily growing degree day accumulations could drop by 50% and prolong the dry-down period in fields not maturing early from drought. For an explanation of how growing degree days affects corn silage maturity progression, see Corn Silage Approaching Maturity - Moving Past Thumb Rules.
Table 2. Target moisture content for corn silage, depending on storage structure
For a comprehensive review of best management practices for harvesting, storing, and feeding silage, please see From Harvest to Feed: Understanding Silage Management.
Source : psu.edu