In the history of agriculture, the long period of the <<Green Evolution>> was replaced by <<Green Revolution>>, which took place in the 1950s - 70s and was acompanied by an abrupt increase of power consumption of agriculture, a rise in crop production, destruction of the resources of the biosphere and environmental pollution. A comparison has been made of the phenomenological models of agroecosystems corresponding to tire ideas of the first and second <<Green Revolution>>. The basic ideas of the proponents of the second <<Green Revolution>> are being analyzed, along with the possibilities of rising the biological potential of agroecosystems by reinforcement of the feedback system. It is shown that the second <<Green Revolution>> will ensure the pursuing of the ecological Imperative but will inevitably lead to a certain decrease of agricultural production. Therefore it is impossible, given the present demographic situation. A slow second <<Green Evolution>> is likely to take place, during which agriculture will smoothly integrate with ecology.
