You are all wrong.
1. Slaves were compensated in the form of free room and board, the ability to marry, practice a trade and could earn freedom. After earning freedom, the majority stayed on or owned houses and plantations of their own or even slaves of their own.
2. It was incredibly efficient for many and produced the greatest wealth which enabled places like Nottaway Plantation to exist. Nothing like that existed in the North. It was inefficient for some, like Thomas Jefferson, whose slaves bankrupted him as they kept growing in numbers and he had to build more housing and grow more crops to feed them.
3. Slaves were far from lazy. It is a liberal retelling of revisionist history to think that slaves were beaten and treated so badly. They grew up side by side their white families, the blacks helping to raise the whites and showing them how to farm and the like. The white children played with the black children and so on.
4. Harvests were never ruined.
You are talking modern history.
They may have helped raise whites , although I personally doubt it, but to make the statement that they showed whites how to farm defies logic.
How can a people, who at a fundamental level, have almost no background in manipulating their land for food production, be in any position to teach others how to farm.
Whites along with all other non African races practised farming to a much higher degree than the bulk of the African populations. Yes Africans did partake to some small degree in farming, but long before America was even populated by Indians, white people were manipulating their land for food.
The skills of farming were developed by the people of the caucuses.
Africa was a land rich and plenty in food and the African man had to catch his prey, this needed the ability hunt in packs,run and attack prey.
Fast reactions, efficient and explosive running capabilities were required for survival. Planning and strategic capacities to manage crops and survival within colder climes was not required.
