If the heavy equipment is electric I'll allow it since heavy equipment for multi crop farming just isn't there yet, but man don't I wish we could do the three sisters with tractors and combines.
A life goal of mine is to try to develop tools to help automate sustainable agriculture as much as possible. As I see it, part of the reason we keep on doing the monocultures is because the alternatives are just so dang labor-intensive, and anything that helps sustainable polycultures, agroforestry, etc. be more automated and less labor-intensive makes it easier for us to finally kick our current soil-destroying and ecosystem-obliterating habits.
Just don't grow things on an industrial scale, because that is very destructive. Small and local. How was it grown traditionally, before fossil fuels flattened the land? On smaller patches. I'd probably compare it to how corn is grown here in the mountains in Southern Europe: small fields, 50x50m max. That lends itself to these fields being separated by hedges where important partner plants and medicinal plants for your fields and meadows grow, and where wildlife finds a spot to hide. This kind of small scale gardening and agriculture still works in many parts of the world and still produces more than 50% of the food (I might be wrong on that but I remember reading it somewhere).
Monoculture farming propagates plant diseases and results in a more fragile crop harvest. For example, if a region like the Midwest has a major explosion in corn borer populations, corn yields will be devastated. Monocultures are far less resilient during drought and other climate change caused problems. It also results in massive amounts of overproduction, especially when combined with industrial farming. The lack of biodiversity also hurts surrounding land and animals. I think it's enough of a reason to simply not create boring landscapes full of a single crop. In all, a solarpunk community in an anarchist society should be able to grow enough food to meet their needs through community and individual gardens, with enough to make it throughout the year and help other communities nearby.