Corn Silage Dry-Down: Week of August 31, 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. Table 1 includes crop progression for the week of August 31st, with the following definitions:
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 | 8/31/26 | 69.0% | 2314 | 0.57% |
| Beaver | P1159Q | 5/19/26 | 8/31/26 | 61.5% | 2102 | -- |
| Butler | -- | -- | 8/31/26 | 62.5% | -- | -- |
| Butler | CHEM 7530S | 5/19/26 | 8/31/26 | 63.0% | 2088 | -- |
| Franklin | 207-27 STX RIB | 5/7/26 | 8/31/26 | 65.0% | 2576 | 0.57% |
| Franklin | 203-15 STX RIB | 6/12/26 | 8/31/26 | 73.0% | 1981 | 0.57% |
| Franklin | 209-15 STX RIB | 6/16/26 | 8/31/26 | 71.0% | 1893 | 0.43% |
| Lancaster | P0817Q | 5/20/26 | 8/31/26 | 70.0% | 2261 | 0.86% |
| Lancaster | P13777V-2 | 5/20/26 | 8/31/26 | 68.0% | 2308 | 0.57% |
| Lancaster | P0817Q | 5/16/26 | 8/31/26 | 70.0% | 2366 | 0.57% |
| Lancaster | P1380Q | 6/2/26 | 8/31/26 | 71.0% | 2467 | 0.57% |
| Lancaster | P13476Q | 5/18/26 | 8/31/26 | 69.0% | 2429 | -- |
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 publication: 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), Stephen Campbell (Butler), Kasey Hower (Berks), Tosh Mazzone (Franklin), and Heidi Reed (Lancaster).
