What Moisture Should Hay Be Baled At? (UK Guide)
Getting the moisture level right when baling hay is one of the most important factors in producing a high-quality crop. Bale too wet and you risk mould, spoilage, or even fire. Bale too dry and you can lose leaf content and reduce overall quality.
Understanding the correct moisture range — and how to measure it — helps ensure consistent results and reduces costly mistakes.
What Moisture Should Hay Be Baled At?
For most conditions in the UK:
👉 Hay should typically be baled at around 14–18% moisture
This range provides a good balance between:
- Minimising spoilage risk
- Preserving nutritional value
- Maintaining bale structure
Typical Moisture Guidelines
- Small square bales: 14–18%
- Round bales: 14–16%
- Large square bales: 12–16%
Larger, denser bales require slightly lower moisture levels, as they retain more heat internally.
What Happens If Hay Is Too Wet?
Baling hay above the recommended moisture level can lead to:
- Mould growth
- Heating within the bale
- Spoilage during storage
- Reduced feed quality
In more severe cases, excess moisture can cause spontaneous combustion, particularly in tightly packed bales.
What Happens If Hay Is Too Dry?
Hay that is too dry can also cause problems:
- Increased leaf loss (reducing feed value)
- Lower overall bale quality
- More breakage during handling
While dry hay is safer to store, overly dry material can reduce the value of the crop.
How to Measure Hay Moisture
The most reliable way to check moisture is by using a hay moisture meter.
Handheld Moisture Meters
A probe meter allows you to:
- Check moisture before baling
- Test individual bales
- Monitor stored hay
👉 Ideal for spot checks and flexibility
In-Baler Moisture Meters
Fitted directly to the baler, these systems:
- Measure moisture continuously during baling
- Provide real-time feedback
- Help you adjust as conditions change
👉 Ideal for larger-scale operations and improving consistency
Agreto Hay Moisture Meters
We supply reliable moisture meters designed for agricultural use:
Agreto HFM II (Handheld)
- 50cm probe for deep bale readings
- Suitable for hay and straw
- Ideal for spot checks and stored bales
👉 (Link to HFM II product page)
Agreto PFM II (In-Baler)
- Measures moisture in real time during baling
- Suitable for round and square balers
- Helps maintain consistent bale quality
👉 (Link to PFM II product page)
Best Practice for Accurate Readings
To get the most accurate results:
- Take multiple readings across the field
- Check different parts of the bale
- Test throughout the day as conditions change
- Don’t rely on a single reading
Weather conditions, crop type, and time of day can all affect moisture levels.
UK Conditions to Be Aware Of
In the UK, haymaking can be unpredictable due to changing weather conditions.
Key things to watch:
- Overnight dew increasing moisture
- Humidity levels affecting drying time
- Short weather windows for baling
Using a moisture meter helps remove guesswork and ensures better decision-making during these conditions.
Final Thoughts
Baling hay at the correct moisture level is essential for producing a high-quality, safe, and valuable crop. While the general target is around 14–18%, the exact level will depend on bale type and conditions.
Using a reliable moisture meter — whether handheld or in-baler — allows you to monitor moisture accurately and make better decisions throughout the haymaking process.