I am far from an expert but I recently watched an interesting video that is still fresh in my mind that mentioned this.

From what was said is it was a combination of things. That they got academic experts from the USSR after others from Western nations couldn't be attained due to sanctions. These experts mentioned that they should plant crops close together to save land and also produce more as the same species shouldn't compete for resources.. He was wrong but to be fair his theory was true when it came to the same genetic family which is what he most likely did in a controlled lab environment. However this resulted in many crops not doing too well.

Another aspect was during industrialisation many people had to be moved away from farms and too the cities meaning less people to work the land

That there was also a drought in much of where the farmland was with apparently 60% of the land not receiving any rainfall for over a year

Then they also tried eradicating pests which backfired due to a lack of understanding of biodiversity and ecology at the time. One they tried killing were the local sparrows because they were eating miniscule amounts of grain (from what I remember was about 4grams of grain a month) but what they didn't know is these birds kept a lot of other worst pests away such as locasts.

So based on my limited knowledge and understanding is it failed due to a lack of knowledge/understanding of farming with a mix of poor planning/preperation with a dash of environmental mismanagement. Which in a way could be seen as "fair enough" as many were poor, uneducated and just coming out of serfdom. But it also depends on how you consider "failure", whilst millions died in the famine you now have a successful and industrialised country that went from peasantry to where they are today in under a century. Kind of a double edged sword really.