carbon footprint for local food was higher than stuff flown in from Africa and they had to shut up.

For starters I don't believe that. African farmers might have less tractors but they burn a lot of manure, food and coal for heat.

Even if true, carbon footprint isn't the only factor when considering where to buy your food. Shifting to more food imported from africa will just drive industrialization in africa.

They all have solar panels

No they don't and even if they did the manufacturing of solar panels and batteries is not carbon neutral.

At what point do rich western farmers say "it's going to be more cost effective to employ a couple more people and use the tractors less"?

You need to look at the bigger picture. There is no point at which western farmers will say this. Why? Because the hiring decision is made by very very large companies tapped into international secret societies. These secret societies work together to push plans towards globalism and the genocide of western peoples. Only locally OWNED small and midsize farms are going to consider hiring more people.