Corn Silage Dry Down Update: Week of August 27

 

Harvesting corn silage at the optimum dry matter is critical to optimize corn silage quality. The best way to know the moisture of your corn silage is to test it. Use this method to check for moisture content at home.

 

In the past, our tactic has been to monitor the moisture of representative fields and then estimate harvest dates by assuming a dry-down rate of approximately 0.5% per day. For this you need an initial moisture. However, some farms and custom harvesters could benefit from longer range forecasts of harvest timing so they can plan to optimize the harvest from multiple fields or farms. One older rule of thumb in some areas has been to estimate harvest approximately 45 days after silking.

 

Cornell research has shown that tracking the growing degree days after silking is a better monitoring technique for silage moisture than relying on the old adage of 45 days after silking. Depending on the climatic conditions in the late part of the growing season, silage harvest may occur within 35 days in a hot, droughty year. However, their research found that tracking accumulated GDD after silking resulted in a more consistent prediction of the date at which the plants reached a 70% moisture content. Cornell researchers recommend monitoring plant moisture at 750 GDD after silking with harvest occurring approximately 800 GDD after silking. Once the silking date has been determined, you can estimate the sampling and harvest dates using the Cornell GDD calculator.

 

To get an estimation of current field conditions around the state, extension educators have begun dry down sampling. This chart illustrates dry-down testing and growing degree day accumulations for this week’s sampling effort.

 

 

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