Straw-for-muck agreements: The benefits and how to do it
© Tim Scrivener Muck-for-straw exchanges can bring mutual gains for livestock and arable businesses.
The arable business provides straw for bedding and, in return, can integrate organic manure into the soils it uses for crop production, while the livestock farm has an outlet for nutrients over and above its own requirements.
Historically, deals have been informal, but with more regulation and extra value in the trade, formal agreements are now more commonplace, says Paul Macer, a consultant with Kite Consulting.
See also: Expert advice on setting up the perfect umbilical slurry system
“NVZs [nitrate vulnerable zones] and nitrogen loading have been with us for a while, but now we have more attention being paid to the Farming Rules for Water in England.
“These are slightly more specific in terms of matching fertiliser use to crop requirements, so some more heavily stocked livestock units are needing to find an outlet for their nutrients.”
There are considerations to bear in mind to achieve an exchange that both parties will gain from, as Mr Macer explains.
What situations do exchanges work best in?
Straw and manure are both bulky products so keeping the exchanges as local as possible is a good thing: moving muck a long way is expensive.
It used to be largely based around farmyard manure (FYM), but now that more dairy units have slurry separators to separate their solids, they have a material that isn’t just a low dry matter liquid slurry and one that is more transportable.
Table 1: Approximate value of straw and farmyard manure |
|||
|
Nutrient content |
Fresh weight (tonnes) |
Phosphate and potash content |
Financial value |
|
Winter wheat straw |
1 |
6g P2O5/t 48kg K2O/t |
£26 |
|
Cattle farmyard manure |
1 |
1 kg N/t 3kg P2O5/t 9kg K2O/t |
£7 |
|
Source: AHDB, published August 2021 |
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Who should be responsible for what?
Who is responsible for baling, loading, haulage and spreading varies on a case-by-case basis and largely depends on who has the flexibility, the machinery and labour.
Can there be issues with weed seeds/blackgrass?
Several arable clients we work with are looking to close the loop; their clean straw goes to a farm and, in exchange, it only has muck back from that farm to protect itself from getting an infestation.
There are some potential issues with ryegrass seed getting into arable crops, but most dairy farms cut the grass before it has headed.
How do you work out a fair exchange?
From RB209, we know the likely availability of nutrients in muck, but I always suggest getting the product analysed so you know exactly what you are dealing with.
When you have that information, a calculation can be based on current fertiliser prices.
Table 2: Typical financial value of livestock manures |
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|
Manure |
Application rate |
Available nitrogen (kg N/ha) |
Total phosphate (kg P2O5/ha) |
Total potash (kg K2O/ha) |
Total value of N, P and K |
|
Cattle farmyard manure (fresh) |
20t/ha |
18 |
64 |
188 |
£142/ha |
|
Pig slurry (4% DM) |
50cu m/ha |
108 |
5 |
110 |
£191/ha |
|
Poultry manure (40% DM) |
6t/ha |
46 |
72 |
90 |
£127/ha |
|
Source: AHDB, published August 2021 Note: The values assume that the manure is spread in the spring onto a medium soil at P and K Index 2 and incorporated within six hours. Purchased fertiliser price assumptions: Nitrogen (N)= 85p/kg, Phosphate (P)=66p/kg, Potash (K)= 45p/kg |
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But there are other intangible benefits that need to be considered, such as the residual nutrients that are not necessarily available to the following crop but will become available further on in the cycle, and the benefits to soil health and quality from organic matter build-up.
Those are a major building block to future production, but the financial benefits are more difficult to quantify.
Are there any tax considerations?
If you are selling something and buying something back, even if there is no money changing hands, it should in theory go through the books.
But if you are trying to equalise the value – for instance, exporting manure with a value of £10,000 in exchange for straw valued at £10,000 – one cancels out the other.
Case study
Farming on the periphery of a large arable region is allowing a Shropshire dairy farm to reap the mutual benefits of a muck-for-straw exchange.
The Thomas family runs a large-scale business that produces a lot of muck and uses a lot of straw.
For five years, they have had an informal arrangement with an arable farm where Mr Thomas had worked as a student.
The arable farm wanted to introduce livestock into the rotation and, initially, the Thomas’ sent 100 of their heifers there for grazing. That arrangement then escalated to exchanging straw and muck.
Mr Thomas hauls the muck to the farm at no cost and the arable farm bales, stacks, and loads the straw. In return, Mr Thomas pays for the haulage.
“We value the straw at £80/t and the muck at £10/t so, when taking some of the haulage and other costs into account, we exchange 7t of muck for 1t of straw,’’ he says.
He has no history of blackgrass on his farm so there is no risk of infestation on the arable farm.
Both parties win from the agreement, Mr Thomas believes.
“They are getting organic manure into their soils and are growing better crops as a result, and we have an outlet for our manure.”
The slurry is separated and can be stored on redundant beet pads on the arable farm to use when needed and when the weather allows.
Mr Thomas says agreements only work if both parties gain equally.
“Both sides have to win from it. In our situation, a lot is done on trust – it is a gentleman’s agreement.
“It is a simple system, but I am a big fan of simple things because they generally work.’’
Agreements often lead to other opportunities: the arable farmer now combines Mr Thomas’ wheat – they share machinery and Mr Thomas grows maize on the arable ground.
