Managing Risk of Damage or Losses in Stored Grains

No business can survive if value is not added to the product that it is trading in. In the grain storage industry, there are many risk factors that can affect the quality of the product the market to customers. These include:

It is possible to address these quality issues to still ensure that a quality product is delivered in the end. The well-known saying in the grain storage environment that “problems can be mixed away”, is not always the best option. Let’s review some ways for managing these risks.

Lower Grades

In theory, a silo bin would be allocated for each grade, but this practice is not always viable and makes it very difficult for depot personnel to handle small quantities of lower grades/class of grain due to the lack of space/silo bins/silo bags. It is imperative that the depot manager knows the overall environmental conditions in his area that may influence the quality of the harvested product. Particular attention must be given to the weather conditions during the growing and drying process of the grain. Examples of these include:

• Drought and cold will result in small or shrivelled kernels.
• More than normal rainfall during the growth phase will result in the appearance of fungi, under-developed cob and more poisonous seeds.
• Strong winds during the growing season may result in uprooted plants and more soil and rocks in the product.
• Excessive rain during the drying season may result in water damage, discolouration, sprouted seeds.
• Early cold or frost during the drying phase may lead to frost damage and empty shells.

The depot manager will only be able to upgrade received product if he is aware of the quality of grain that will be harvested. This information will assist the manager to plan properly in order to mix lower grades with higher grades. This mixing action means that a lower grade should, in relation, be mixed with the higher grade during the dispatching of grain. This must be done at such a rate that the good product is not adversely affected.

It is imperative to remember that if a buyer has purchased Grade 1 product, he is entitled to a product that meets the Grade 1 requirements.

The mixing of products is a complex process and is not applicable to all products. It is possible for the depot manager to manage its defects above the sieve. The problem occurs when the maximum defects occurs above the sieve and breakage in the silo takes place. In this instance it would be extremely difficult to upgrade the product.

Certain grading factors can be mixed with success, but some factors cannot be upgraded.

• Low hectolitre mass can be mixed with high hectolitre mass to gain a mass that meets the Grade 1 requirements (wheat).
• Low protein can be mixed with high protein to obtain an average protein that meets the Grade 1 requirements (wheat).
• Heat damage in sunflower and soya beans can be mixed with other products to get the percentage below 10%.
• Regardless of the product, it is impossible to get rid of a musty, sour or undesirable odour.
• Most of the other grading factors can, however, be mixed away.

Poisonous Seeds

If a consignment contains more poisonous seeds than the Act allows at the time of delivery, it is a good practice to screen the seeds before storage and return the screenings to the producer. Remember, the screenings sold by the depot must comply with the same laws that apply to the prescribe product. The Consumer Act does not allow the sale of screenings with more seeds than is allowed by the Act.

Grain that is infected with poisonous seeds can also be mixed with clean grain to reduce its presence in the sample. Remember that lighter seeds, such as cocklebur and fine bur weed, move to the surface while Datura and other smaller seeds settle at the bottom of the silo/truck due to the vibration that occur. It remains a good working practice to rake the obvious cocklebur of the top of the load before taking the grain in. Many loads are placed in dispute unnecessarily because the buyer observed cocklebur on top of the load.

Screenings

A good storage technique is to remove at least 50 to 100 tonnes from each silo bin and returning it back to the top of the product in the silo. This will spread the breakage that is caused during intake into the empty silo and spread it through the rest of the product in the silo. The benefit is not only widespread screenings, but drawing the screenings from the silo bin means that the core of broken grain in the silo is disturbed and thereby combatting insect infestation. It also improves aeration and/or even circulation fumigation.

Many of the screenings, however, can be mixed with other grades during the discharge. Ensure that the additional breakage during the loading process does not reach the maximum limit. Buyers make a point of returning consignments with excessive screenings. From a business point of view, it makes sense to negotiate with the seller to accept such a load at a reduced price. This allows the buyer to benefit from the screenings that will be lost during the screening process and the discount he negotiated to take the load. The seller saves on the high transport cost as well as the offloading and cleaning of the consignment.

Insects

Insects cannot be mixed away or managed. Grain, oil seeds or dried beans are either used whole or in processed form for human and animal feed. It is therefore essential that hygiene practices should be strictly applied to ensure that the product does not become infested. There is absolutely no tolerance for insects in a consignment during delivery.

The buyer is very concerned about the quality of its product and cannot afford to take contaminated product to the market. Due to the competitive market his brand name is very important.

The old way to get rid of insects by suing a screen to sieve out any insects is just no longer acceptable. Most of the adult insects are removed this way but the immature stages hatch about 1 to 6 days later in the processed product. This means that the consignment is returned to be fumigated involving huge costs. In some cases, the brand name of the buyer associated with infected stock can lead to legal action against the company.

Buyers are increasingly likely to keep sealed samples of consignments and if insects hatch within these sealed samples after a time, the whole silo bin in which the load was received is withdrawn and fumigated.

Product Damaged During Storage (Heat and Fungi)

A common problem with long-term storage is moisture migration in the product mass. Moisture migration is the result of convection currents that is caused by temperature differences in the grain mass and heating the silo by sunlight. Most managers expect that when heat damaged product is dumped into the bottom of a truck and good product is dumped on top, the problem is mixed away. The truth is that of there is more than 3-4% heat damaged kernels in the grading sample, the sample will emit a typical musty, sour smell. In many cases the damaged grain will be on top of the heap of grain if “side tippers” is used to transport the grain.

Undesirable Odours in the Product

The occurrence of undesirable odours at depots are not common. These odours are more noticeable from producer deliveries or where the transport company’s trucks were not cleaned. The problem remains the depot’s problem is loaded/offloaded. A bad smell in small quantities could be detected due to insects and/or rodent infestation, especially in bag stacks.

Mixed Grain

Grain mixing is part of the storage industry and in many cases this is not declared as it should which leaves the depot with a problem when the product is loaded. The failure to clean elevator boots as well as conveyor belts and shuts only aggravate the problem.

Foreign Material

The appearance of foreign material in consignments create problems for the storage facility. Although foreign material is deducted from the producer (so-called clean basis wheat, sunflower and soya beans) upon receipt, it usually increases during storage and handling.

Other products that appear in the consignment are considered as foreign material and will result in a greater mass loss when the mass deduction is made.

Dangerous, Unwanted and/or Chemical Substances

The appearance of dangerous, unwanted or chemical substances may originate at the producer, transport company or the storage facility. Product that contains these substances may not be traded. The producer or the depot may spray/treat the product with a chemical that is not acceptable to the buyer. In some cases, a fungus killer/seed treatment chemical is present in the product. It may also happen that the transport company previously transported a substance that is dangerous for humans and/or animals (stones, scrap metal, animal material, fertilizer and coal).

The depot cannot accept product that has been exposed to these substances and will have to be returned.

Abrasion

All grains will wear the surfaces that are in contact with flow. The amount of wear will vary according to the type of grain, the volume of grain, speed of grain, the impact of grain streams on surfaces and the slope of the contact surface. All aspects of the distribution system are affected by these characteristics. When analysing systems, components such as spouting, transitions, gates, valves, conveyors and future access to these components must be designed into the system for maintenance requirements.

Corrosion

Wet grains ground processed grains and chemically treated grains can corrode standard carbon steel fabrications. Each grain type to be handled must be checked to determine if stainless steel is needed or will reduce possible life cycle costs. If water wash down, or cleaning-place systems are required, materials used for fabrication in the distribution system should be considered.

All storage systems must be designed to adequately protect and preserve the quality of the grain. Whole grain can sprout under certain conditions and will also attract moulds, insects and rodents. In addition, the storage of grain presents several safety issues which needs to be provided for.