Phacelia is grown as a green manure and the farmer will plough it back into the soil to enrich it. This can be done on a smaller scale in ordinary gardens. Another plus point for phacelia is that bees absolutely love it.
Phacelia is usually grown nowadays, in this area at least, to provide nectar for pollinators. If it’s grown as a green manure it’s usually ploughed in before it flowers. The second pic looks like a field of Winter Wild Bird Seed Mix. I can see several types of plants there including Fodder radish. Farmers are encouraged to grow Fodder radish and many other plants to provide seeds for birds in the winter … see herehttps://www.gov.uk/countryside-stewardship-grants/winter-bird-food-ab9 Also check out this place on Fbookhttps://www.highashfarm.com/