I've heard it's highly dependent on the nutrient BBC Radio investigated it in 2019: https://www.bbc.co.uk/programmes/w3csz3ry https://www.bbc.co.uk/programmes/

I've heard it's highly dependent on the nutrient BBC Radio investigated it in 2019: https://www.bbc.co.uk/programmes/w3csz3ry https://www.bbc.co.uk/programmes/w3csz3ry The next year they did the same for soil degradation, and found it a similarly complex topic: https://www.bbc.co.uk/programmes/p08dx986 https://www.bbc.co.uk/programmes/p08dx986 Both are <10 minute MP3 downloads