When I was young, and even more recently our fields were never this colour. Now winter sown Oilseed Rape, (Canola) means that even by early April many of our fields are turning yellow. Oilseed Rape or Turnip Rape has been cultivated for centuries but it is since the 1970's that it has become an important crop in the UK. It has multiple uses, as an animal feed, to produce oil for industrial use and to produce high quality oil for the food industry. Canola oil (or rapeseed oil) contains both omega-6 and omega-3 fatty acids in a ratio of 2:1 and is only second to flax oil in omega-3 fatty acid. It is one of the most heart-healthy oils and has been reported to reduce cholesterol levels, lower serum tryglyceride levels, and keep platelets from sticking together. Industrial use included the production of Biodesel for powering motor vehicles.
Rapeseed is a heavy nectar producer, and honeybees produce a light colored, but peppery honey from it. It must be extracted immediately after processing is finished, as it will quickly granulate in the honeycomb and will be impossible to extract. The honey is usually blended with milder honeys, if used for table use, or sold as bakery grade.
Unfortunately some people appear to be allergic to the pollen and it has been linked with adverse affects for asthma and hay fever sufferers. The other problem is that vast acres of monoculture crops may lead to a reduction is some of our wildlife and wild flowers, as Fields are enlarged and hedgerows disappear, but this is a problem with all intensive agriculture and not just this crop.