I would also point out that this isn't just the Free World vs the Reich.
Germany isn't alone. Even if Germany itself has educational limitations, advances in technology can still propagate through contact with their allies or those countries that are friendly towards Germany.
Regardless of how it plays out, I think the Germans would probably build things to last instead of the planned obsolescence that a lot of consumer goods are built with today.
German citizens might have less advanced but longer lasting things.
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I'll also say the Germans never banned the teaching of evolution.
Though one interesting thing, for a given value of interesting, was how they tweaked certain subjects to try to push students towards their thinking.
One thing they were big on was euthanasia for those who were mentally or physically handicapped, so they'd do things like slip that into the math problems. Instead of stuff like, "If I have five apples and eat two of them, how many apples are left?", what they would do is give questions asking students to calculate how much it would cost the state to keep handicapped people alive. To make them view the handicapped as nothing more than a burden.
They called it social arithmetic.
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And on rereading the interlude you're talking about Bookmark . . . Those barren fields were deliberately abandoned. At the time of that update, they aren't even trying to cultivate them. Though it is rather strange that they're barren. You'd think nature would be reclaiming the abandoned fields.
They can't work everything at once. What they would be doing is basically picking out the best land for <insert resource here> and using it to form the nucleus of a given regions colonization efforts. Then they would spread out from there and, one day, those fields might possibly be worked again.
One such area would be the Ukraine Breadbasket. With the arable land Germany already had, as well as that breadbasket, they can afford to leave most of the farmland seized from the Soviets abandoned.
There would have to be a full blown catastrophe for Germany to suffer food shortages.