Straw is composed mostly of the stalks left behind a combine after threshing out the grain or oilseeds and is often regarded by many arable farmers as a by-product at best and a nuisance at worst.

One of the snags with straw is that valuable dry days are needed to get it baled before the fields can be cleared to allow the next crop to be sown. That uses men and machinery at a busy time when harvesting is still underway and next year's crops have somehow to be sown.

At one time straw was simply burnt where it lay in the rows, or swathes as we call them. That was a quick and easy way of getting rid of it to allow ploughing or cultivations to get started. A good burn also helped to reduce weeds.

The downside of straw-burning was that there was a risk of accidents as smoke billowing from burning fields drifted across roads and reduced visibility. Ash was carried on the wind to settle on washing hanging out to dry, or drift through open windows to mess up homes of the house-proud.

So a law was passed banning straw-burning that forced farmers to look at other methods of disposal like baling or incorporating it into the soil.

Modern combines can have straw-choppers fitted that chop up the straw as it leaves the combine and spreads it on the land. It is then incorporated into the soil as part of the preparation for sowing the next crop as well as returning valuable crop nutrients to the land.

The main uses of straw are as fodder for cattle, or bedding for cattle, sheep and pigs, so when straw-burning was banned livestock farmers thought they would be guaranteed cheap supplies. Thanks to the introduction of set aside by the EU that didn't happen.

To be eligible for support payments, farmers had to set aside part of their arable acres as fallow. That way, they were in effect subsidised for not growing crops - in other words, paid not to work. That stupid scheme, and a switch from cereals to other crops like oilseed rape, coupled with the tendency for modern grain varieties to have shorter straw to help prevent them being flattened in wet stormy weather, led to a shortage of straw.

While many arable farmers may regard it as a nuisance by-product, livestock farmers currently end up paying about £75 per tonne to have good barley straw delivered compared with bulk loads of barley grain that costs them about £105 per tonne. Mind you, straw is not nearly as dense as grain, so haulage can account for more than a third of the delivered cost of straw.

Currently the UK produces between 11 and 12 million tonnes of straw annually of which about 5.5 million tonnes are incorporated into the soil.

Latest complication for the dynamics of the straw market is the increasing popularity of burning straw - mostly wheat straw - to generate electricity. That currently uses about 0.5 million tonnes annually and could be using between 1 and 1.5 million tonnes annually in the next few years as new plants come on stream.

Located in the main arable areas in England to minimise the cost of haulage and ensure an adequate supply, some of these plants, like the one at Sleaford in Lincolnshire that came on stream in September 2014, consumes 240,000 tonnes of straw each year.

Straw needs to be worth at least it's fertiliser value when chopped and incorporated into the soil in addition to the costs of baling it and loading it onto lorries, otherwise arable farmers will simply chop it. The problem for livestock farmers, who are mostly located well away from the main arable areas, is that they will have to pay at least that price to compete with biomass electricity generation plants as well as the hefty cost of haulage. With margins in the livestock sector notoriously tight, that could leave many struggling to justify the use of straw for bedding and looking for alternatives.

Some use woodchips, or sawdust as substitutes with varying success, but they too are becoming expensive. Others mix sawdust with straw, to help absorb moisture and make the straw remain dry for longer. Others use a layer of gypsum - a very absorbent by-product of the plasterboard industry - under their bedding straw.

Keeping livestock clean and dry when they are indoors is becoming an expensive business.