The moral of the tale, which can also be extracted from other discussions of agriculture, is that the capitalist system runs counter to a rational agriculture, or that a rational agriculture is incompatible with the capitalist system (even if the latter promotes technical development in agriculture) and needs either small farmers working for themselves or the control of the associated producers.
So "rational agriculture" requires either "small farmers working for themselves" or "the control of the associated producers."
We see where this puts Marx in relation to pre-industrial figures, like Jefferson*, in the first case; while his criteria for evaluating large-scale agriculture as it has developed since can be found in the second. What is the common principle between examples?
*It should be said, in principle.