why has much of this year's wheat crop rotted?

[porphyro]

because of excessive rainfall, much of britain's wheat crop has not been harvested. Could the fields not have been covered with protective plastic sheets or something similair? How does the wet weather impair the use of conbine harvester? Does excessive rain increease the chances of disease? Does the rot also relate to lack of sun?

[wildwood]

Plastic over the field just wouldn't work. Apart from the cost, where would the water go? Excess water would have to go somewhere! I think the trouble may be the water table under ground. If it is too high the water will just not drain away and make the soil soggy. At some places vehicles will just bog into the ground.
Grain has to have a certain moisture content to be harvested, if not dry enough it will soon develop fungi in storage.
I do however like your question and thinking like yours has led to many helpful inventions over the years.

[JonnyBoy12]

Well, they could use all the plastic from the 17 billion carrier bags we use in the U.K. every year. That is enough to cover 3 whole counties laid out. Would you like to help me put them all together, and lay them out. It would only take us several lifetimes.

[Clanad]

Here, where I live in the western U.S., were on the edge of the Great Plains breadbasket wheat growing area. It produces millions of bushels of wheat and other small grains. Although wet conditions, in and of themselves aren't deleterious to the health of the grain, it does promote the growth and propagation of various fungal infections. These can be controlled, but the cost of chemicals adds to the production of the grains. Chemical control is the first choice, behind correct and timely fertilization.

It's well known, at least here, that the lack of crop rotation adds to the fungal persistence. But the farmer finds himself in a bind, since, all the modern equipment to grow various crops has become so specialized that it's difficult, if not impossible to change the crop he's growing. Wheat and barley have become very profitable so there's little incentive to change crops.

In actuality, you idea of covering the crop would only add to the problem, since the various fungi are somewhat controlled by air circulation... which would be lacking in a covered crop, no? Interesting question, however...

[Ice.Maiden]

I suppose that vast greenhouse-type coverings, with integral sprinklers could be the answer, but the cost of deploying them, plus good drainage systems'd put the cost of whatever crop up to astronomical levels. However, once in operation, surely the cost'd come down again in real terms, as farmers wouldn't lose whole fields of wheat or whatever?

[taichiperson]

I'm so sorry to post on a 'serious' question, but that's the funniest thing I've read for ages. Thanks porphyro, I needed a laugh. Am imagining farmers rushing out with vast sheets of plastic every time it rains!!!! To be more serious, yes, using heavy machinery in waterlogged fields would be difficult......