Breeding for wet, heavy clay soil

[Cotyledon]

Adapting plants to clay would involve planting large amounts of material, like 10,000 seeds of a single species and then selecting the plants that do the best and then repeating the process. It requires quite a bit of time and space and a willingness to plant hundreds of thousands of seeds that you expect will not make it.

Since clay is defined by very small particle size and it breathes very poorly, there is a limit to how much oxygen that clay can hold, unless it is amended. A clay based loam is the most fertile of all soil types I am aware of, clay is as much as one third of the best soil, the rest is sandy material and organic matter.

In nature nothing ever stays the same, clays are colonized by plants that break them up, allowing more plants to grow on them, gradually transforming them over time. Human lives are so short however, that we rarely have much insight into this. What this means, however, is that in nature, plants tend to modify the clay they grow in, rather than adapt to it.

To some people this topic is a bit like asking if anyone has worked on developing a type of human that can breathe underwater. Plant roots can breathe in clay just as well as a human can breathe water.

[pawpawPapi]

I didn't mean to imply easy.  Agriculture extension offices could give you a good list of plant varieties they'd recommend for a clay trial, how many plants to grow out would be determined by the conditions and what plant. There have been many plant varieties bred for clay conditions, however. https://journals.ashs.org/hortsci/view/journals/hortsci/16/1/article-p30.xml is a good read to get some idea on what allows certain plants to be successful in waterlogged conditions, some traits may be applicable to other cultivated species. Speed is variable in adaption, but can be faster than you think https://www.earth.com/news/fish-evolution-takes-place-in-decades-not-millions-of-years/, a very extreme example I know, but something like corn or melons could grow almost anywhere productively in 4-5 generations.

[stone]

Walking in my yard today, I am reminded how tiny my raised beds of excellent soil are, and how much land I have around them that is heavy, dense clay prone to flooding.

Has there been much breeding work on vegetable and fruit varieties that thrive and fruit in heavy, wet clay?

I could much more easily grow a large number of plants if I could use the clay with minimal improvements beyond hoeing or tilling. This would especially useful for landraces or other outbreeding species.

I wish I had your heavy wet clay...
Holds moisture / nutrients...

when I was in the heavy clay at my previous house, a few of easy plants to grow were sun chokes, canna, and apios.

At my current house in the sandhills... not having much luck with any of the three... or much else.

[Cathy A]

I've found sunchokes and raspberries grow well in clay.

But the sunchokes must be fenced, or rodents eat every trace of the roots.