This is very interesting and I found some more information on what type of farming he does.
Interview for BBC radio in 2018. made on his farm
https://www.bbc.co.uk/sounds/play/b0b3b4lx. It has a bit more information than the article. There's also a mention of the initiative to spread the type of wheat growing he uses, collecting old grain varieties (older than cca early 1900s) and developing genetically-diverse populations of heritage cereals. I went down the rabbit hole and found the link for that:
https://www.heritagegraintrust.org/. It has some basics and a list of readings for further info. Do check the
video (header) at News and Event part of the site, it's lovely.
A lot of information this article
https://www.thelandmagazine.org.uk/articles/continuous-grain-cropping
He explains the system he uses which he calls Continuous Grain Cropping (CGC) - draws on the philosophy and farming practices of Masanobu
Fukuoka and One Straw Revolution, and of Marc Bonfils who adapted some of Fukuoka's principles to wheat cultivation. He's using "genetically diverse and constantly evolving population of traditional varieties of wheat" a.k.a. landraces. Also mentions that this system mimics the ecological structure of a natural grassland.
"The success of this approach depends on six principles:
(i) early autumn planting of winter cereals that require vernalisation (ie a cold period).
(ii) high genetic diversity within the crop (i.e. populations or genuine landraces)
(iii) undersowing cereal crops with short white clover
(iv) no ploughing or inter-row tillage
(v) leaving all crop residues on the soil surface after the harvest, and
(vi) no use of artificial fertiliser or agri-chemicals."
There is a more detailed description of how and why, I'll just mention that he doesn't do anything with smaller weeds so combined with no till it adds to the diversity of groundcover. Also that different diseases are present but at low levels and he gets good yeld, all due to the very high diversity of crop genetics, biodiversity within the field (microbial, plant and animal), low levels of soluble nitrogen and having healthy agro-ecosystem in general.
He also mentions one particular field where he's growing wheat 6 years in a row without any problem, I don't know if he had longer experiments on smaller plots. There was a mention of wild (field) flowers in the groundcover together with the clover, can't remeber in what particular source I found that bit of information.
There's also a really nice short history of agriculture in general and development of wheat through the time in this article, I found very interesting details and would recommend reading through it.
One of the problems that a lot of organic farmers have with (not just) wheat is that they are using modern varieties so they still have a problem of monoculture with very low genetic variability that is very nutrient hungry because they were bred that way, so what they are really doing is a variation of modern / industrialized farming just without chemical input (all cides and fertilizers). There are some varieties bred for organic production that have a bit more genetic variability but that is still way to low for any versatile disease resilience.
Info in another article: "Letts gradually bulked up the grain from his initial research
project with over 250 ancient varieties to create a hardy, genetically diverse crop with very good yields." (
https://www.resurgence.org/magazine/article3811-the-rise-of-real-bread.html). That's an impressive number! Although it may represent all the grains he grows, not just wheat, it's still very high considering those are all varieties older than 100 years. That is a really nice starting point for the
landrace(s) he created and a great source for resilience of crops.
My general conclusion is that he does a a form of regenerative farming with a particular emphasis on high genetic diversity of his crops for long term resilience. I like it and I think he's got it pretty good. And I really like that they support many others to adopt those practices.
If we are talking about long term
sustainability of such system, it would probably still be good to mix it up from time to time, in terms of, for example, growing three diferent type of crops and switch the fields every 10 or 15 years, or something on those lines, could be a combination with animal use etc.