Corn Silage Dry-Down: Week of August 24, 2026
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.
Dry-Down Rate: The rate at which a particular hybrid is losing moisture each day, as compared to the previous moisture check. Rates will average about 0.5% moisture loss per day, ranging between 0.0 and 1.0% in extreme weather.
| County | Hybrid | Planting Date | Sampling Date | Moisture Content | Accumulated GDD | Dry-Down Rate |
|---|---|---|---|---|---|---|
| Berks | P11056V | 5/19/26 | 8/24/26 | 73.00% | 2170 | 0.86% |
| Franklin | 207-27 STX RIB | 5/7/26 | 8/24/26 | 69.00% | 2418 | 0.00% |
| Franklin | 203-15 STX RIB | 6/12/26 | 8/24/26 | 77.00% | 1823 | 0.33% |
| Franklin | 209-15 STX RIB | 6/16/26 | 8/24/26 | 74.00% | 1735 | 0.33% |
| Lancaster | P0817Q | 5/20/26 | 8/24/26 | 76.00% | 2129 | 0.11% |
| Lancaster | P13777V-2 | 5/20/26 | 8/24/26 | 72.00% | 2164 | 0.68% |
| Lancaster | P0817Q | 5/16/26 | 8/24/26 | 74.00% | 2225 | 0.43% |
| Lancaster | P1380Q | 6/2/26 | 8/24/26 | 75.00% | 2310 | -- |
Be cautious of localized differences in planting date, hybrid maturity, and weather conditions. Not all hybrids will progress through dry-down the same, and not all hybrids retain the same appearance at a certain moisture content. Be aware of expected weather in the coming weeks; if cooler weather trends continue into September, crop maturation may slow considerably. Table 2 highlights the target crop moisture levels for an efficient fermentation that minimizes losses to seepage or mold.
| Structure | Whole-Crop Moisture % |
|---|---|
| Horizontal Silo | 65-70% |
| Conventional Upright | 63-68% |
| Oxygen-Limiting Upright | 55-60% |
| Bag | 60-70% |
| Pile or Stack | 65-70% |
For a comprehensive review of best management practices for harvesting, storing, and feeding silage, please see the Penn State Extension article: From Harvest to Feed: Understanding Silage Management.
Many thanks to the county-based Penn State Extension Dairy and Agronomy Educators who make this effort possible, including: Angie Breneman (Lancaster), Kasey Hower (Berks), Tosh Mazzone (Franklin), and Heidi Reed (Lancaster).
