Farmers looking to upgrade their grain handling facilities have two main options: invest in a new shed or opt for silos.

Each has its own advantages and disadvantages. Silos offer efficient use of space while sheds are often more versatile and are suited to ground with a lower load-bearing capacity.

However, it’s not always a straightforward decision and choosing the wrong option can inadvertently add to longer-term running costs.

See also: Tips to achieve successful long-term grain storage

There are planning, grain quality and future cropping considerations that also need to be taken into account before deciding.

Here, Farmers Weekly asks an expert what farmers need to consider.

Business case

The starting point, according to Scott ­McArthur, projects director at grain system specialist McArthur BDC, is to define the business case for investing in grain storage.

Start with the basics: what quantity of crop  do you need to store and for how long?

Also, what different crops do you need to keep segregated? The number of crops to segregate can significantly affect storage costs.

Ultimately, grain storage has to bolster the profits of an arable business, and this underpins everything. “We have had farmers who have reduced the number of crops they grow after carrying out a business case for storage, as it highlighted that some crops were not worth the extra costs.”

Once farmers have confirmed that there is a good business case, the next step is to identify the priorities for the new storage being planned, as this can influence the choice of system. Scott highlights three areas: flexibility, quality and operation costs.

Flexibility

For some farmers, flexibility is a key requirement as rotations change year to year. Think about how many divisions are needed in the store and whether they need to be moveable.

“Free standing walls have become more popular in recent years,” Scott says.

Does the shed design lend itself to being divided more in future, if you decide to grow more crops? Silos tend to be less flexible, as they will store only a single crop – which is fine when you are storing mainly feed wheat.

Quality

Quality refers to keeping grain in good condition. This means having good climate control, crop conditioning and keeping vermin out.

Is cleanliness more important to your buyer? For example, premium-earning crops or a more discerning buyer may have greater demands.

Storing crops for longer for marketing purposes also requires good moisture control. This is where silos may be the preferred option, being better suited for longer-term storage and for pest control.

Operational costs

This third area is where farmers can get caught out. What does it cost to run the storage system? Think about the power and labour needed to dry, cool and handle grain.

“Some farmers may opt for the cheapest shed to build, but it may have higher operational costs longer term,” says Scott. “A good example is labour, where a simple shed may have a high labour requirement for pushing up grain and loading it out too.”

This may be less of a problem for farms with livestock or that grow produce, as they may have labour to utilise. But for pure arable farms, farmers may be looking to keep labour to a minimum and this can be reduced by loading sheds with a central elevator or opting for fully automated silos.

Also consider the equipment requirements, he says. Does the system require a telehandler to load and unload, and at what cost? Some farmers again will already have a telehandler and labour to utilise.

Scott highlights that there could be other factors not be under the farmer’s control that may determine choice of storage.

Planning

Scott encourages farmers to start having early conversations with local planning officers or a consultant. Are you looking to build storage as a permitted development or are you looking for full planning permission, as that can steer the decision. Full planning does cost more and is more onerous.

Under permitted development, farmers can build a shed of up to 1,500sq m  and up to 12m height. “This could store 5,000t of wheat, which is a good amount of storage without having to go through the full planning process.”

However, with silos you get efficiency as you go taller. So with 12m, you could end up with four to five separate silos to keep within the height restriction rather than one shed.

Scott McArthur © McArthur BDC

Ground conditions

Farmers also need to determine ground conditions for the site and know what it sits on. Factors include the load-bearing capacity of the ground, height of the water table and site levels. Therefore, farmers will need a site survey to answer these.

If the bearing capacity is low, a shed may be the better option, with its a bigger footprint spreading the weight.
Knowing the height of the water table is important to avoid flooding in tipping pits and below-ground elevators.

Armed with a site survey, farmers can then get reliable quotes. For example, the site may need excavating to make it level. But without a topographic survey or boreholes, it’s impossible to have cost certainty.

“You may get a quote for a shed and then find you need 1,000t more hardcore and the costs can spiral,” Scott says.

Even better, bring in the services of an engineer who can design the storage up front. This can be done by a grain systems specialist who can look after the whole process including planning and ground investigation.

“With the design, farmers can then put it out to tender and get companies to quote, on a like-for-like basis.”

Timing

The third area is timing. Farmers need to allow enough time for all these points to be addressed. Ideally, to avoid the last-minute stress of trying to complete it ahead of harvest, allow at least 18 months from starting to develop the project to needing to use the store.

“This gives farmers time to ensure they make the right decisions.”

Once farmers have chosen which system, Scott offers some pointers on getting the most from them.

Sheds

Starting with sheds, there is scope for different shapes and he advises thinking about the shape of the pile of grain.

Is it a shallow or a deep pile and is it going to be peaked to the apex?

Opting for a longer or square shed will have implications on the cost. For example, a higher heap needs higher walls which will add to costs.

Shed shape also affects the complexity of a conveyor system to fill the shed.

The most efficient is having a peaked heap along the apex with a single conveyor running along the length. A square shed may be cheaper to build, but this will be more expensive for handling equipment as you may need side elevators and conveyors to fill into the sides and corners.

However, as mentioned before, this is less of an issue for farms with labour to utilise and a telehandler available.

© McArthur BDC

Silos

Silos offer space-efficient storage, and taller, narrower silos are more cost-effective than wider, shallower ones.

However, farmers need to consider the visual impact of a tall silo and they may be limited by height restrictions.

Where farmers are opting for multiple silos, the most efficient installation is to have them in a straight line along the elevator.

However, if the site is on a slope, it may be necessary to compare the cost of site levelling against banking the silos into multiple rows.

Access

One final point which applies to any type of new storage is the need to access machine parts safely.

What are the maintenance needs and where are the machines located? Some conveyors need bearings to be greased ­regularly.

If they need regular access and are at height, there may be a need for a staircase and catwalks. Otherwise, a ladder may be sufficient.