To answer what was different - planning and hindsight.

The nazi political and bureaucratic machine was aware that the Great War was lost because of the collapse of the Home Front, mainly due to the State's inability to tackle economic issues that arose from the lack of agricultural production (War is hell.) .

The Ministry of Agriculture led by Richard Walther Darre, and his assistant that would later take his place, Herbert Backe, have thus set up a sort of a planned economy for Germany's agricultural products, where the Ministry defined the prices of raw and processed agricultural goods, instead of them being defined by supply and demand. In case of a war, they planned, Germany wouldn't repeat the same mistakes and face starvation, and thus defeat.

While the harvests in the upcoming years were pretty bleak, the harvest of 1938. was so good it has managed to make a decent surplus of primarily grain, which was used to patch up supply deficiencies in the upcoming war years.

A lot of German calorie intake in the 1930s came from processed livestock products - dairy products, butter and such. As such, similar to the Germany's industry and its lack of raw materials, it depended heavily on the import of grain to be able to feed its horde of livestock. Due to the allied naval blockade, Germany mostly imported its grain from southeast europe, USSR, Yugoslavia and Romania, and would continue those countries' grain production capacities after it invaded or puppeted them.

This dependancy on livestock, while seeming like a liability however, allows for a desperate contingency plan - in case of not enough grain being available to feed the livestock, one could just slaughter them and use their meat instead - while this would seriously cripple production capacity in the years to come, it would manage to offset hunger and starvation by a year at worst.

Sources:

Adam Tooze : Wages of Destruction, the making and breaking of Nazi economy 2006.