Corn generally looks good in the region, let’s get it across the finish line with a well-timed harvest to maximize quality. The dry spring and wet summer have resulted in lots of variability in many fields. Corn maturity is behind average even though recent hot weather has helped. The only way to be sure of picking the best harvest timing is to base your decision on whole plant dry matter.
CCE and WAC teamed up with Dairy One, and their portable NIR, to test corn dry matter this week and the results are in the chart to the right. Samples varied from ¾ milk line to ears still in milk stage, but ear stage alone was not adequate to guess dry matter (DM) content. DM is the best way to decide on harvest readiness, because it best predicts fermentation quality. We recommend 32 – 36% DM for bunk silos and bags, 35 – 38% DM for upright silos. Remember proper length of cut, thorough kernel processing, and adequate packing are all critical in making quality corn silage.
The samples tested on September 14th averaged 29% DM with a range of 23% DM to 32% DM. With the help of Dairy One NIR, were able to measure starch content as well, which averaged 31% with a range between 25% and 36%.
As corn matures it will increase in starch content, and increase in yield. Harvesting too early will sacrifice yield and energy content. Harvesting too late will yield poorer fermentation and lower starch digestibility. Corn will mature and dry down at about ½ to ¾ point of DM per day. Only two fields tested have reached 32%DM and are ready to chop right now, ½ of the fields need another week, ¼ are 10 days to two weeks away, while the other ¼ are two weeks or more from harvest dry matter. See chart below for more details.
Harvesting too early (<32% DM) results in reduced yield, reduced silage starch content, challenged fermentation and increased risk for silo juicing (which is a potent pollutant as well as tough on silos). Harvesting too late (>40% DM) will lead to poor fermentation and lower starch digestibility. Continuing to monitor whole plant DM is critical. Getting DM into the target zone yields best fermentation. Use of reputable inoculants helps on corn silage, especially when it is getting dry. Inoculants containing Lactobacillus Buchneri have been shown to be effective with corn silage. Increasing chop length with wetter silage may also reduce silo juicing.
Sample Results 9/14/23
| Town | Ear Maturity | DM% | Starch % |
| Davenport | ½ milk line | 29 | 32 |
| Edmeston | ¼ milk line | 28 | 32 |
| Edmeston | ½ milk line | 29 | 33 |
| Edmeston | ⅓ milk line | 30 | 34 |
| Edmeston | ¼ milk line | 30 | 35 |
| Edmeston | ½ milk line | 31 | 35 |
| Edmeston | ½ milk line | 32 | 36 |
| Franklin | E. Dent | 27 | 30 |
| Franklin | ½ milk line | 30 | 35 |
| Franklin | ⅔ milk line | 30 | 33 |
| Franklin | ⅓ milk line | 33 | 34 |
| Guilford | ½ milk line | 29 | 34 |
| Guilford | ¼ milk line | 30 | 31 |
| Halcott | Milk | 24 | 25 |
| Halcott | Milk | 24 | 27 |
| Halcott | Milk | 26 | 28 |
| Hallstead | Milk | 28 | 29 |
| Kortright | Milk | 27 | 29 |
| Kortright | E. Dent | 31 | 32 |
| Kortright | ¼ milk line | 32 | 32 |
| Meredith | Milk | 24 | 25 |
| Norwich | ¼ milk line | 31 | 34 |
| Roxbury | ½ milk line | 29 | 30 |
| Roxbury | ½ milk line | 30 | 33 |
| Sidney | E. Dent | 28 | 29 |
| Sidney | ⅓ milk line | 29 | 32 |
| Stamford | E. Dent | 24 | 28 |
| Stamford | Milk | 25 | 29 |
| Stamford | E. Dent | 27 | 31 |
| Stamford | ¾ milk line | 30 | 30 |
| Summit | ⅔ milk line | 29 | 32 |
| Tompkins | Milk | 29 | 31 |
| Tompkins | Milk | 30 | 31 |
| Tompkins | E. Dent | 30 | 32 |
| Tompkins | E. Dent | 30 | 31 |
| Tompkins | E. Dent | 30 | 30 |
| Unadilla | ½ milk line | 29 | 31 |
| Walton | ¼ milk line | 29 | 31 |
| Average | 28.7 | 31.2 |
Thanks to Dairy One Integrated Farming Solutions Consultant Tim Lewis for coming to both dry down days and providing rapid analysis of our samples!
