Still nonsense. And, you conveniently left out the word totally. Here is the sentence I commented about:
At the time the Constitution was written, the economy of the southern states was totally reliant on slave labor.
The word totally makes the writer's contention a ridiculous statement. And this was in relation to the ratification of the US Constitution. Cotton was not yet king in the 1790s; tobacco was probably king. The cotton gin was invented in 1793 and cotton became king in the decades after that.
The statement was out of context and mostly hyperbole.
And if twenty smaller farms produce a thousand bales of cotton and one plantation produces a thousand bales, which produced what was needed domestically and who produced a surplus? Cotton was and is a commodity and all producers small and large contributed to whatever surplus was produced.
But the underlying contention -- that the south's economy was reliant on slave labor -- is true.
To that point, the plantation owner could well produce a 1000 (or more) bales of cotton. But twenty of the smallholders were more likely to produce something like 50 bales of cotton, not a comparable 1000. A standard bale is 500 lbs -- and that is a whole lot of cotton to pick.
Per the National Cotton Council...
Cotton bolls range in size from under 3 grams to over 6 grams per boll. Seed accounts for about 60% of this weight; the remainder is lint. This translates into about 200 to 400 bolls to produce a pound of lint, or 100,000 to 200,000 bolls per bale.
Pre-Civil War, figure 3 grams per boll (or less). Thus, the simple logistics of a cotton harvest (not to mention the tending) severely limited a smallholder's productivity.
The fact is that the primary agricultural crops of the early south -- cotton, indigo, tobacco, etc. -- were all extremely labor-intensive, thereby lending themselves to a plantation economy. There was a reason why slaves had been introduced into the south in the first place. Which is the same reason why the south's economy remained shackled to them -- until, finally, machinery changed the equation.