I do not know whether the 'Green Revolution' could have taken place earlier. But if it had, it probably would not have prevented Nazism IMHO. Germany's economic problems in the late Twenties and early Thirties were complex and had a lot to do with the breakdown of world trade that followed the 'beggar your neighbor' policies of increasing trade barriers. It had a lot to do with factories being shut down and not producing any more wealth.
The Nazis' 'explanation' for the crisis, however - blaming the Jews - had nothing to do with any reduction in trade or production. It was not based on the idea that less wealth was being produced in an economic crisis, but on the idea that 'the Jews' were 'stealing' Germany's wealth. The way the Nazis saw it, the way to Germany's future wealth also consisted in taking away wealth from someone else (by conquering Lebensraum in the East) rather than increasing production or trade.
So both the 'analysis' of Germany's problems in the Twenties and Thirties and the 'solution' for the future was based on zero-sum thinking, which in this context I take to mean the idea that there is a fixed, given amount of goods, and the wealth of one individual or nation can only be achieved by taking away goods from other individuals or nations.
This zero-sum way of thinking is of course very mistaken, many nations have increased their wealth many times over, without taking anything away from others. But at the same time it is very pervasive, because it does not take a particularly great amount of intelligence to think "If the other guy's share of the cake is getting bigger, mine must neccessarily get smaller."
A much earlier 'Green Revolution' could not have prevented the "Black Friday" crash or the collapse of world trade through the heightening of trade barriers. In OTL there were many German farmers who went bankrupt due to falling grain prices, and although the 'Green Revolution' is a good thing, this one problem is rather more likely to be aggravated than solved by it. Of course conquering Lebensraum in the East is totally superfluous for feeding Germany under these circumstances, but it was already superfluous in OTL. Nevertheless even in this timeline the Nazis might come to power, because their world view strongly appeals to zero-sum thinking, which is mistaken, but pervasive.