An OPI System Can Help You Manage Your Stored Grain in a Delayed Harvest

The early snowfall for Western Canada has had a significant impact on the 2018 harvest. This poses a challenge for farmers who are harvesting, drying, and need to safely store their grain. Grain harvested under these wet conditions will be at higher moisture levels than in an average crop year. Delaying the harvest could also result in an increased rate of grain deterioration and contamination. Crops are at greater risk for rot and mold growth and with the increase in wet weather, crops may develop mycotoxins. Grain should be dried to safe storage moisture levels before winter holding to avoid mold growth. Natural air drying, natural air drying with supplemental heat and high temperature drying are the options that are typically available. Regardless of the drying method chosen, grain in delayed/wet harvest season must be extensively monitored. Wet and damaged grains will cost you money and result in lower selling rates.

Natural Air Drying

Natural air drying (NAD) can be used if grain moisture is no more than 18% for wheat and 14% canola, there is sufficient airflow (1-1.5 cfm/bu) and ambient temperature is above 50C. Fans should be operated to maximize the drying potential with less emphasis on over drying. In delayed harvesting, you may not have the opportunity to dry the grain before winter. In this situation, dry the grain as much as possible, cool it to near freezing temperature, hold it through winter, and then start drying again as soon as ambient air temperature is above 50C. The NAD mode with OPI Blue fan control is designed to maximize fan-run times in optimal ambient conditions.

Natural Air Drying with Supplemental Heat

Natural air drying with supplemental heat (NADH) can also be used where the moisture content is 18% for wheat and 14% canola, there is sufficient airflow (1-1.5 cfm/bu) and the ambient air temperature is more than 50C. Increasing the temperature by a maximum of 80C will lower the humidity of the air to the point where it can be used to effectively dry the grain. Supplemental heaters can be used to extend the natural drying season beyond what is possible with natural air drying only. The NADH mode in OPI’s IntegrisPro system is designed to optimize the operation of the fans and heaters to effectively extend the drying season without over drying the grain.

High Temperature Dryers

If the harvested grain moisture is very high – above 18% for wheat and 14% for canola – then a high temperature
gas-fired dryer should be used to quickly dry the grain to safe storage moisture levels. However, there are added fuel costs to consider in using high temperature dryers and your grain quality may be affected.

Worst-case scenario, when the drying capacity cannot keep up to the high moisture grain being harvested it may become necessary to store wheat at 15% moisture content and canola at 12%, until the harvest season is over and there is dryer capacity available. It is important to realize that this scenario is outside of safe storage recommendations and should only be used as a last resort. The grain held in this condition should be cooled to 10C -20C and the bin cored. Monitoring the temperatures in this situation is critical so that remedial action can be taken if problems arise.


Dryeration is the process where grain is taken hot from a high temperature dryer at 1%-2% higher moisture than required for safe storage. The hot grain from a dryer is filled into a tempering bin with 0.8-1.0 cfm/bu airflow rate, tempered, cooled and dried to safe storage moisture levels by in-bin natural air drying. Then dried grain is moved to a permanent storage bin and grain is aerated to 10C -20C temperature. Using a separate tempering bin will move up to 2% extra moisture out of the grain. Some farms may not have the availability of this extra tempering bin, so grain is tempered, cooled and dried in the same bin. Dryeration reduces the cracks, broken grain and cost of drying and increases drying throughout as grain is coming out at 1%-2% moisture above the target moisture. Uniform airflow rate at 0.8-1.0 cfm/bu is key to the success of dryeration. Large bins such as 105’ have low airflow rate and may not be suitable for dryeration.

Important Considerations

Storing grain through the winter holding period after a challenging harvest season requires intensive monitoring and management. Due to increased broken and fines in the grain airflow through the core is blocked which increases the risk of mold growth, spoilage and development of mycotoxins. It is highly recommended to clean the grain and remove broken grain, fines and chaff before filling the bins. Avoid rapid cooling of the grain in the bin directly coming from high temperature dryer as it causes fissures and cracks in the kernels. Grain should be aerated to 10C – 20C after in-bin drying/dryeration is completed. Increasing grain temperature inside the grain bin is an indicator of mold activity. Grain should be immediately cooled by running the aeration fan. High moisture grain at high temperature creates favorable conditions for mold growth and mycotoxins development.

Damaged grain with foreign material reduces safe storage life and this grain should not be targeted for long term holding through the summer.

Oil seeds such as canola spoil faster than cereals at the same conditions therefore extra care needs be taken in storing. Canola reduces the airflow rate due to its higher resistance to the airflow, therefore, shallower depth should be considered while filling the bin to improve the airflow rate (no more than 20’ grain depth). OPI Blue and IntegrisPro’s grain monitoring and management technology can actively monitor the grain moisture, temperature and detect hot spots, create the rate of temperature change and temperature rise alarms, and automatically control the fan for aerating/drying the grain.

For more information on how you can benefit from an OPI system, contact your local OPI dealer or call toll free at 1-800-661-1055.