They defined organic agriculture as an ecological production management system that promotes and enhances biodiversity, biological cycles, and soil biological activity.

他们将有机农业定义为促进和增强生物多样性、生物循环和土壤生物活性的生态生产管理系统。

This would be a really encouraging sign of life for my alien colleagues because the composition of the Earth's atmosphere can only sustain itself through a biological cycle.

这将是一个对我的外星同事非常鼓舞人心的生命迹象，因为地球大气的组成只能通过生物循环维持自身。