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STORAGE
ADVANCED GRAIN MANAGEMENT TECHNOLOGY
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by OPIsystems, Canada
etting the best return for your harvested crop is all about managing moisture content and delivering optimum quality grain. Advanced Grain Management maximises the return on your most precious grain asset by optimising grain quality and value, while minimising storage costs.
The starting point is bin management: Sanitation:
• Remove all debris inside the bin and on the underside of the aeration floor • Clean the bin walls and spray if needed to remove all insect “safe harbors” • Cut away all vegetation and maintain the area around the bin • Seal all possible entry points for moisture or insects
Loading:
• Fill the bin with clean grain that has <2 percent foreign material (FM) • Core the bin, or level the grain, using a spreader if necessary. This will result in even airflow distribution throughout the bin, which is extremely important for good conditioning results • Filling the bin to the peak with high FM grain will result in little or no air through the dense core – a recipe for disaster
Figure 1
Think of stored grain as an ecosystem. If quality grain is stored at low, uniform moisture content and temperature, it can have an extremely long “shelf life”. Elevated moisture content and temperature renders the grain susceptible to infestation by internal-boring and non-boring insects, reducing value through weight and grade loss (Internal Damaged Kernels/IDK). A high moisture/condensing environment can lead to other microbial activity, such as moulds and mycotoxins. Sprouting becomes more likely in a high-moisture environment. The kernel can also respire over time, whereby the consumption of mass leads to a reduction in test weight. Loss can occur at the hands of birds and rodents. Weight loss can be expressed in general terms as Dry Matter Loss (DML), with Safe Storage Chart recommendations based on the length of time grain can be stored before a 0.5 percent dry matter loss. Being cumulative over the entire storage period, it’s important to know how old the grain is coming into storage. Figure 1 shows the amount of time that oilseeds can be safely stored at a given temperature and moisture content. For example, soybeans stored at 75°F and 14 percent moisture content can be safely stored for 63 days. This assumes clean grain of sound quality. It’s also based on the length of time before experiencing a 0.5 percent DML. It doesn’t mean that grain can’t be stored longer, but rather it questions the viability of storage once the DML exceeds 0.5 percent. Here is the corresponding safe storage chart for corn and cereals (See Figure 2). In this example, we’re calculating “storeability” for more than one set of conditions as we go through a conditioning process. For example, when going through an initial conditioning cycle, with corn at 85°F and 16 percent moisture content for 18 days, 50 percent of the 36 safe store days have been used up (18/36). After conditioning the corn down to 60°F and 15 percent moisture content, the safe storage is then 50 percent of 278, which equals 139 days, for a combined total of 15 safe storage days (18+139).
Early detection
Heating typically starts as a result of microbial activity in a pocket of higher moisture grain. Because grain is such a good insulator, by week three the heating will have started to move vertically up through the bin (by convection) more readily than across the bin (by conduction). By week four, significant spoilage has taken place less than 10’ from the cable, without sensors registering a discernable change. 92 | September 2019 - Milling and Grain