No idea. I have no idea if anyone has looked into this in that much detail. My guess would be that he was wrong, since agriculture would have been even more insensitive to change in many parts of the world (although less so in other areas since monocropping wasn't as common).
In Intelligence Explosion analysis draft: introduction, Luke Muehlhauser and Anna Salamon wrote
As a part of the project "Can we know what to do about AI?", I've summarized my initial impressions of Arrhenius's predictions and the impact that they might have had. The object level material is all draw from Wikipedia, and I have not vetted it.
Taking this all together, based on my surface impressions, I think that this case study gives evidence against attempting to predict the far future being useful: