B. Moisture
Moisture content is reported on official grade certificates, but does not determine which numerical grade will be assigned to the sample. Moisture content is important because it affects the amount of dry matter being sold and purchased. Moisture is also an indicator of whether a need exists for drying, has potential implications for storability, and affects test weight. Higher moisture content at harvest increases the chance of kernel damage during harvesting and drying. Moisture content and the amount of drying required will also affect stress cracks, breakage, and germination. Extremely wet grain may be a precursor to high mold damage later in storage or transport. While the weather during the growing season affects yield, grain composition, and the development of the grain kernels, grain harvest moisture is influenced largely by crop maturation, the timing of harvest, and harvest weather conditions.
RESULTS![](https://grains.org/wp-content/uploads/2018/04/MoistureGraph-1.png)
- The U.S. Aggregate moisture content recorded at the elevator in the 2015 samples averaged 15.7%, which was lower than 2014 (16.6%), 2013 (17.3%), and 4YA (16.2%).
- U.S. Aggregate moisture standard deviation in 2015 (1.53%) was lower than in 2014 (1.84%) and 2013 (2.24%), and 4YA (1.84%).
- The moisture range was less for 2015 samples (11.0 to 23.5%) than for 2014 samples (10.9 to 29.9%) or 2013 samples (10.9 to 28.2%).
- The 2015 moisture values were distributed with 40.7% of the samples containing 15% or less moisture. This is the base moisture used by most elevators for discounts and is a level considered safe for storage for short periods during low winter-time temperatures. Only 19.1% of the samples contained more than 17% compared to 37% in 2014 and 48% in 2013. This distribution indicates fewer samples required drying in 2015 than in 2014 and 2013.
- In the 2015 crop, 19.8% of the samples contained 14% or less moisture compared to 12.4% in 2014 and 10.0% in 2013. Moisture contents of 14% and below are generally considered a safe level for longer–term storage and transport.
- The average moisture contents for corn from the Gulf, Pacific Northwest, and Southern Rail ECAs were very similar in 2015 – 15.7%, 15.7% and 15.6%, respectively.
- In previous years and 4YA, the samples from the Gulf ECA were highest in moisture. In contrast, because of an early harvest and excellent field drying conditions across all ECAs in 2015, average Gulf moisture was the same as the average Pacific Northwest moisture and only 0.1% higher than the average Southern Rail moisture.