Drying and conditioning grain post-harvest for safe long-term storage
Farmers spend the best part of 9-10 months nurturing crops from drilling to harvest – so how should this valuable commodity be treated and stored once it’s off the field? Rachel Hicks reports.
Safe and effective grain storage post-harvest is key to ensuring quality and minimising risk. As soon as grain leaves the field, it should be treated as a food crop and stored accordingly to reduce risk through the food chain and safeguard consumers.
With the main causes of spoilage in stored grain being fungi, insects and mites, the drying and cooling process is key. Chemical treatment is limited by both food safety legislation and failure due to resistance development, so physical control methods and an integrated pest management system are vital. While grain that is sold off-farm before November poses less of a storage risk, it also can command a lower price per tonnage, so many farmers are now storing grain longer in the hope they can achieve almost double the premium with a May movement.
According to Sukup Europe Ltd’s UK sales manager John Statt, while there are UK farmers out there who are very good at drying and conditioning their harvested crops, others have very little knowledge about this very important part of post-harvest commodity care. John says: “Although UK farms have moved with the times in many areas and heavily invested in cultivation machinery and precision equipment for drilling, spraying and fertiliser application, and they have also increased output capacity greatly in the field at harvest with large output combines, unfortunately grain drying and storage equipment has lagged well behind in investment in both infrastructure and technology.
“Many UK farms have seen little investment in post-harvest equipment or storage facilities since the 80s and 90s and, as the output of combines has greatly increased over this time, the grain dryer or intakes have increasingly become the bottleneck in otherwise high output systems.”
Many buildings with on-floor drying systems that were constructed 20 or more years ago are no longer even high enough to tip the latest generation of grain trailer in, which sit higher on their chassis to accommodate larger wheels and tyres used to reduce ground compaction and damage to soil structure in the field. Yet few farmers seem willing to make the investment in new systems.
“Availability of skilled labour is also becoming an issue on many farms, and older grain dryers that require a man to constantly monitor them is not only draining in labour resources, it’s also costly. Equally, the floor stores with drive-over drying floors are often seen as the quick ‘tip and go’ solution in the UK. In years where little or no drying is required they generally are, but grain also needs to be pushed up with a grain pusher on a telehandler, which again takes more labour and obviously requires a telehandler, too. This common practice can also lead to compaction problems in wetter years, in stores not fitted with grain stirrers when grain comes into store at 17.5 per cent moisture content or higher, leading to problems with both the drying and conditioning process,” explains John.
“Those farmers with expertise in this field would always avoid doing this – instead, using a mobile rubber belt elevator, auger, grain thrower or overhead conveying systems to drop the grain in from above to fill the store and avoid the compaction from happening.” It’s the knowledge, experience and attention to detail such as this which will create the most benefit in terms of efficiencies.
Further efficiencies can also be made with energy efficient drying and low labour systems.
The UK grows some of the world’s largest crops in terms of tonnes per hectare, which creates a substantial surplus for trade. While we are yet to see what our future trading relationship will be with our European cousins when we leave the EU, UK farmers need to find a way to successfully compete in the world market as a whole, against grain produced in the Black Sea areas and North America where growing costs are usually much lower and trading prices are reduced, too. On this note, John continues: “For us to successfully compete in these markets, we will have to add value to our exportable surplus in quality, assurance and traceability, and this will require improved knowledge in maximising the value of those crops once it has left the combine and enters the grain store.
“Marketing skills will also have to improve and farmers will potentially have to store grain longer to get the maximum benefit of selling quality grain at market peaks.”
Insulation : Could it save your grain?
Keeping a stable temperature in your grain store is key to preventing spoilage, so it’s worth thinking about any improvements you can make to your buildings. Riva Commercial explains how installing closed cell spray insulation can eliminate condensation, control mould and fungal growth, and maintain temperatures in winter and summer.
With the start of the harvest approaching in a few months, now is a good time to look at your grain store and make any necessary improvements. Maintaining a stable temperature is key to crop quality and reducing the risk of losses – as is good store hygiene, ventilation and a watertight roof.
Choosing to store grain comes with economic benefits as it does not have to be sold for harvest movement and later delivery generally attracts a higher price. Storage comes with its own set of challenges, however.
The main causes of spoilage in stored grain are fungi, mites and insects, according to AHDB. At certain temperatures and moisture content, fungal growth can occur rapidly and lead to the production of the mycotoxin, ochratoxin A. Insect and mite development is also a risk in higher temperatures, while in winter, the grain surface absorbs moisture. Climate change could present further challenges in achieving cooling targets in the future, if predicted temperature increases are correct, AHDB says.
With this in mind, it is well worth investing some time in making improvements to your store now, to help prevent these issues. Installing good quality insulation not only reduces your heating and cooling bills, it also helps to maintain a stable temperature – keeping stores warm in winter and cooler in summer – reducing the impact of environmental temperatures on your grain.
Riva installs Walltite closed cell spray foam insulation, which uses cutting edge technology to control and deplete mould and fungal growth, eliminating airborne mould spores. It also promises zero condensation, reduces heat loss by up to 60 per cent, avoids overheating during the summer, improves indoor air quality and offers protection from severe weather and flooding resistance. By reducing the need for heating in winter and fans in summer, the system can reduce energy bills by half, according to the company.
Liquid installation means the spray technology can access critical, inaccessible or curved areas, sealing off all gaps and air leaks. And, as it has no food value, it can help to eliminate infestations.
Harvest management made simpler
Technology using moisture sensors and automated control software can improve accuracy and save valuable time spent monitoring and managing dryers, according to Kentra Grain Systems.
Kentra’s Dryer Master DM510 control system promises to provide reliable grain drying with minimal manual intervention.
A moisture sensor installed in the conveyor line takes grain from the dryer, while an inlet sensor, usually fitted at the top of a continuous flow dryer, can detect changes in the moisture content of incoming grain. Control software uses readings from these sensors to calculate the residence time needed to hit an average target moisture and automatically adjusts the discharge rate accordingly. Both sensors automatically compensate for grain temperature to ensure accurate readings and the post-drying sensor is simple to calibrate.
Kentra managing director Barry Higginbottom says: “The ability to predict when, say, wetter incoming grain will fill the dryer takes all the guesswork out of managing the system and results in more accurate and consistent drying.”
The company does not recommend taking a ‘set and forget’ approach – it is good practice to have someone supervise the drying operation and repeat the sensor calibration two or three times a day. “But the accuracy of this automated control system will give the store supervisor confidence to attend to other aspects of harvest management without neglecting the dryer,” Barry adds.
According to Kentra, the system also offers significant cost savings. Manual grain dryer management involves responding to samples taken after the grain has dried. To avoid being caught out there is a tendency to be cautious, resulting in grain being dried beyond the optimum, which is costly in energy and weight loss.
Barry explains: “Assuming a grain price of £100/t, a farm drying 20,000t of grain has only to save one per cent moisture in over-drying to regain £20,000 in lost revenue. A farm drying 4–5,000t of grain a year would recoup the £10,000–£12,000 purchase of a Dryer Master system in three years – a bigger operator even sooner – while also saving time and hassle at harvest.”
The Dryer Master display provides a quick view of drying status and settings, a manual option for operators who prefer to make their own discharge rate decisions, a number of alarm alerts and a print-out for records. If internet access is available, the display is accessible on a farm office computer or remotely via a smartphone or other mobile device.
Partnership allows complete grain solution
A new partnership has seen UK manufacturer Perry of Oakley Ltd team up with SiloMaster, to offer their customers a complete grain handling, drying and storage solution.
Perry of Oakley has more than 70 years of experience as a manufacturer of materials handling and drying equipment, while SiloMaster’s team of engineers has been designing and manufacturing silos for over 50 years. This partnership will allow the two companies to offer a complete solution and support other dealers – from concept, to layout and design, through to manufacture, supply, installation and ongoing support.
SiloMaster has developed a new range of flat bottom and hopper bottom silos, to which Perry of Oakley has some exclusive rights. The silos will be designed and manufactured to the highest specification, with an ethos of ‘on time, right the first time,’ the company says. They will be adorned with both the Perry and SiloMaster logos, as a symbol of the companies’ new cooperation.
Perry’s full product range includes continuous mixed flow driers, belt driers, chain and flight conveyors, belt and bucket elevators and belt conveyors, among other drying and handling solutions for grain and bulk materials.
Working with farmers to boost production
For over 50 years, multi-disciplinary engineering firm, Edwards Engineering, has worked with farms and farmers across the UK.
With high levels of service and, most importantly, effective solutions, the Edwards’ team recognises the need to ensure any works undertaken don’t affect production or quality, delivering successful operations, such as upgrading grain dryers, replacing aging equipment and expanding stores, whilst creating minimal disruption to the important production schedule.
Edwards works with leading grain equipment manufacturers including Cimbria, Skandia, Guttridge, Svegma, Alvan Blanch, Perry and Carier.
Edwards Engineering managing director Sandy Kirk, said: “As a fully independent business, we offer professional, impartial advice that delivers the best result, whatever form that takes. We’re not tied to any one manufacturer and have our own drawing office and extensive fabrication facilities allowing us to respond rapidly.”
From small farmers to large scale projects with grain co-operatives and traders, new builds to replacements and upgrades, every customer and project is important. Edwards Engineering is determined to ensure completion on every contract on time, to the agreed specification and within budget.
H&K Farms, Lockerbie, said: “Edwards Engineering supported us with the installation of a Charlesfield Farm Grain Dryer. The team was amazing and very conscientious. To think that we did not have a single hiccup is a miracle these days. I cannot recommend them highly enough.”
Versatile dryer a popular choice post-harvest
As producers of post-harvest equipment, Alvan Blanch manufactures the Continuous Double Flow grain dryer, which, according to the company, can process any combine-harvestable crop, no matter how wet or dirty. Alvan says the dryer is highly fuel efficient, versatile and has automated control options, making it a popular choice for farmers.
In partnership with Soby, the company offers a complete grain handling solution – with conveyors, augers and elevators designed to work in conjunction with the drier.
The Rotary Cleaners and Aspirators are available in six different models, with two size options per model (plus the choice of two, three, or four screens). They are designed for powerful pre-cleaning and seed cleaning/grading. Interchangeable screens allow for the processing of multiple grains, all in one machine.
Alvan Blanch also offers a complete range of farm machinery, including: Mixers, Hammermills and Roller-Mills – a range that is designed to allow on-farm grain processing and feed milling. Through utilising home-grown grain, the costs are reduced and the quality of the feed for livestock has provenance.
Every piece of machinery is built to last, the company says, usually providing over 40 years of reliable service. All solutions are custom built, whilst promising to remain simple to use and maintain.
Through Alvan Blanch’s nationwide network of dealers, and its service engineering team, annual drier servicing and technical support are provided. An internal parts department also ensures farmers can source parts for their machines.
Take noise issues in account
So many of Bennett and Co’s projects require some noise attenuation, as stores get larger and require bigger fans – whether grain, potato or onion stores. Similarly, large continuous flow dryers that might be running all night during harvest. With planners looking at this in far more detail, fully cognisant of the requirements of the National Planning Framework and the British Standards referred to for rating and assessing noise coming from grain stores and the like, it is important that this noise (and its likely effect on surrounding residents and even wildlife) is taken into account at the outset of a new project.
Bennett and Co has considerable experience in looking at these noise issues in the early stages of a new project or in designing ways to reduce the noise of an existing facility or upgrade.
Solutions may just involve re-siting the proposed development or correct fan selection. Alternatively, longer silencers on axial fan units, box silencers or acoustic louvres on air intakes, acoustic fences or earth bunds, or noise insulating fan houses can reduce noise to acceptable levels.
If you are planning a project, whether for grain, potatoes or vegetables, visit the Bennett and Co website to see more details of recent projects and submit your email address in order to receive a quarterly newsletter, Crop Storage Update.
Wireless-style fan automation
Grain store specialists Evans and Pearce developed a system to turn grain ventilation fans into automated units, capable of cooling crops without the high costs usually associated with wireless temperature control. Four years on, the company says it has won praise from users for its sensible approach to fan automation and simplicity of use.
Evans and Pearce is encouraging growers to consider the now-proven system, called Grain Fan Assist, as a genuine alternative to more costly wireless systems.
Each fan is fitted with a control box that takes a signal from an ambient air temperature sensor and a grain temperature probe. The controller monitors the difference in air and crop temperatures, triggering fans to operate when air is cold enough to effectively cool. As external temperatures rise, the fan switches itself off to avoid warmer air being blown through the crop – a technique that has been shown by AHDB to reduce energy usage by up to 40 per cent.
It can be fitted to any number of new or existing fans for around £250 and requires little, if any, input from an electrical contractor.
Stores fitted with additional extraction fans to draw clean air into the building, can be further enhanced with Extraction Fan Assist, to wirelessly detect when any grain ventilation fans are operating. This triggers the main extraction unit into life and ensures synchronised running of grain and building ventilation fans – all essential to keep costs down and cooling rates up.
A variant called Multi Fan Hub is also available so that multiple fans can be automated from a central control panel – each built to customer requirements.
Storage : Minimising waste, maximising returns
Planning for harvest is a continual cycle and with many crops taking 11 months to grow, it is essential that your hard work is supported by the perfect storage solution, says Graham Heath Construction.
Many external factors can affect a crop once it is in storage – from moisture, fungi, mites and general hygiene; through to pests and structural issues, such as bowing walls and leaking roofs. It is therefore essential that suitable storage conditions are created to minimise waste and maximise returns.
Storing grain in tired buildings that allow access to the elements will only cause problems. Damp conditions act as a breeding ground for many species of insects and although drying the grain after combining will slow down insect development, it is essential that moisture content is kept to 12 per cent to minimise the risk.
A new grain store will offer a clean, dry, well-ventilated and watertight construction. High quality CE-marked steel and materials will prevent rain and other such weather penetrating the building. Quality roofing will also reduce or eliminate birds and pests from gaining access.
Concrete panels are a key feature in Graham Heath Construction grain stores. They are easy to clean, hygienic and exceptionally durable, withstanding the force of a grain harvest with ease. Concrete panels are also quick and easy to install, simply slotting between steel supports.
From the steel frames to the concrete panels, the key elements of every Graham Heath building are produced at its UK site.
Protect your stores from insect attacks
A significant quantity of the world’s grain is lost each year during storage, largely due to insect attacks. It is therefore essential that grain storage buildings are cleaned out before use, says Pan Agriculture Ltd.
Grainstore is a Deltamethrin-based insecticide, developed by the company, that controls a wide range of insects including grain moths, Indian meal moths, flour beetles, sawtoothed grain beetles, grain weevils, bean weevils, rice moths, grain borers and warehouse moths.
The product’s mode of action is through direct contact and ingestion. It has no with-holding period and requires just one application per year. It is available in two formulations, both offering high protection against stored grain pests, Pan Agri says.
Grainstore 25EC can be used diluted as an admixture, or as a treatment for grain storage buildings and equipment, but it can also be applied directly to the grain. The fabric of the building should be treated 3–4 weeks before storing the grain. This formulation offers grain protection for up to two months.
Meanwhile, Grainstore ULV is a ready-to-use insecticide which does not require additional water. It can be used as an admixture and can be applied directly to bulk grain. It offers up to 12 months’ protection against crawling insects and up to three months’ protection against flying insects. The ULV formulation is ideal for use by contractors using low volume foggers.
Insect fumigation and colour sorter tackle rejected loads
Crop production company L F Pearce & Son has added a Satake colour sorter to its portfolio of products, making it possible to remove vomitoxin, fusarium, ergot and discoloured or damaged grain.
The sorter also has the ability to ensure accurate admixture removal and species separation, plus bushel weight and Hagberg improvement. This can enhance the crop value as well as avoiding costly crop penalties and increasing the premiums paid to growers.
For farmers facing challenges with rejected loads from bugs in crops, the company offers insect fumigation using K-Obiol ULV6, which is applied on intake of the crop and then cleaned through the Westrupp cleaner. There is no withdrawal period for the product so loads can go straight back on the lorry.
With severe wet weather and flooding in autumn, resulting in problems getting crop in the ground, the company says growers may wish to keep some grain for longer. L F Pearce & Son has storage for more than 10,000 tonnes of crops for those who are thinking of keeping some grain back. All bays in the facility have under-floor ventilation and condition and there is a system in place that allows grain temperature to be monitored 24/7. A skilled groundwork team can also erect grain stores and complete all aspects of groundwork and concreting, the company adds.
Promising year ahead
2019 proved busy for BDC Systems, supplying Svegma driers from Dorset right up to Fife, with sizes ranging from 18–52t/hr. The outlook for 2020 looks equally promising.
One 2019 installation of note was a 52t/hr Svegma continuous flow grain drier with vertical turboclean dust extraction fans and touch screen control panel. All the elevating and conveying equipment offered 80t/hr and was from the Skandia ’H’ line range of heavy duty kit. A complete dust extraction system was designed and supplied by BDC Systems, with a JKF filter at the centre of the plant. The machinery is controlled from a 5m long PLC control panel incorporating two 22in plc screens with remote access and viewing.
Svegma driers are available in a variety of sizes from 5t/hr to over 100t/hr. They are of fully galvanised construction and suitable for both indoor and outdoor applications. New for 2019 was BDC’s own MMS System which allows real-time monitoring of the moisture content of grain on the inlet and outlet elevators of the drier.
Skandia handling equipment is available exclusively in the UK from BDC. Skandia offers three ranges of equipment from 30–600t/hr, suitable for general farm use through to commercial use. Belt and bucket elevators, chain and flight conveyors, belt conveyors, silo sweep conveyors and dust and chaff extractors are all available, generally with a 4–5 week delivery period.
Bulk grain drying : Overcoming challenges
The fully automated Rekord Grain Stirrer promises to overcome the challenges of drying grain in bulk by preventing grain capping and crop compaction, as well as reducing the static air pressure – which significantly increases airflows. The crop is dried evenly, according to Rekord Ltd, making sampling easier and reducing the risk of rejected loads.
Available in 4–16m, the stirrer can improve the efficiency of bulk drying stores and boost drying rates by as much as 50 per cent, the company says. The machine is switched on at the control panel and automatically travels between moveable end stops, covering around 40ft/hr.
Variable pitch augers can work in crop depths from 4–14ft and draw grain along the entire length of the auger, ensuring total mixing of grain to the full depth of the crop. As there is no longer a drying front or risk of capping, a controlled higher air temperature can be applied, Rekord explains.
The standard stirrer has two carriages and four augers, while the smallest has one carriage and two augers. On request, the company can supply a stirrer with three carriages and six augers.
Rekord supplies a comprehensive range of agricultural machinery, including power harrows, mini balers, balers and rollers.
Hand-held moisture test delivers ‘lab standard’ results
Despite a difficult harvest in 2019, with heavy rain and high temperatures, testing schemes suggest a hand-held instrument is offering laboratory-standard moisture and hectolitre results, outperforming many more expensive instruments.
Farm-Tec’s DICKEYjohn GAC 2500 benchtop has delivered leading accuracy over the past five harvests, the company says. Now, analysis of results from leading UK proficiency testing schemes indicate the Mini GAC 2500 hand-held has an average accuracy of 0.2 per cent (compared to oven results) on wheat, barley and OSR.
The GAC 2500 family of moisture meters, which are based on 149MHz technology, are distributed and supported by Farm-Tec, who develop the UK-specific calibration on a wide range of commodities (wheat, barley, oats, rapeseed, peas, beans, etc.) and monitor the UK calibrations throughout the year.
Going against the grain
Broomex C-Max push brooms are different from others – designed with patented side retainers to hold bulk volumes of material in front of the brush, the C-Max avoids spillage at the sides. Coupled with the ease and speed of mounting the brush to a telehandler, skidsteer, fork lift or category II three-point hitch, this makes the C-Max the ideal broom for anything from large-scale grain moving and clear-up, to a whole range of uses around the farm.
The end brushes are carefully twisted so they pull material away from a wall or curb, sweeping it into the main path of the broom. With no belts, chains, pulleys or anything else to potentially create down time, and no flying debris, the C-Max is safe and maintenance-free.
Hardwearing polypropylene bristles with a high-tensile steel broom head and mounting hardware, in a heavy-duty powder coated finish, ensure the brooms are durable, designed to sweep up to 450 miles before changing bristles. The broom also provides a squeegee effect on wet floors.
Broomex bristles are so rigid that the brooms stand on their own weight, meaning they don’t have to be placed in some kind of stand when not in use.
Available in 1.5m, 1.8m and 2.4m widths, the Broomex C-Max demonstrates how a broom can be different and yet very effective.
Latest addition to grain drying range
Mobile batch grain dryers from Italian manufacturer Mecmar are the most recent addition to Morgan Farm Machinery’s range.
The dryers have capacities ranging from 7–55t, with the most popular sizes being 20, 24 and 35t electric automatic dryers. When used in conjunction with a loading hopper or trench conveyor, these will automatically load, dry, cool and empty. Having a setup such as this can create a ‘tip and go’ system. The range includes models that can handle both small and large batches of grain and are easily transportable, making them a great option for farms of various sizes, Morgan says. Automatic drying systems also offer continuous operation that can be linked to a grain handling system. Burners stop as soon as the grain reaches the
required temperature, making it a fully automated process.
Morgan Farm Machinery also supplies and installs fixed grain equipment, having worked on a range of large and small projects across the UK. Grain store buildings, state-of-the-art continuous flow dryers, Challow wooden floor drying systems, centrifugal drying fans, constant humidity controllers and concrete
wall panels are all available.
Traditionally, the company sold farm machinery and continues to do so, as well as refurbishing Opico and Mecmar grain dryers and supplying genuine parts and services for dryers nationally. All reconditioned dryers are covered by a season’s parts and labour warranty.