As we continue our week looking at the causes and consequences of increasing food prices, we hear how the world's largest grain trading companies are making huge profits at the same time as food prices increase rapidly. Some charities are now calling for them to face a windfall tax. We speak to IPES-Food which has been monitoring how recent global events are affecting global food prices. How sustainable is the meat you eat? Some people pay more for organic and grass-fed beef and lamb with the belief that it will have less of an impact on the environment, however conservation writer George Monbiot says they are wrong, as it is some of the most damaging. Anna Hill speaks to George Monbiot and Cambridge University professor Donald Broom who says there needs to be a wider assessment of what is meant by sustainable. And we’ve reported regularly about the use of robots on farms, from weeding crops to picking fruit. But they are still too expensive for many farmers to think of using. Now the idea of hiring in robots, rather like seasonal workers, is on the cards. Presented by Anna Hill Produced in Bristol by Natalie Donovan