一、耕作制度研究中的一个重要问题人类从自身的农业生产实践中,逐渐认识到自然界是一个有机结合的复杂的生态系。在这个生态系中,阳光及辐射热、水分,含有二氧化碳、氮和氧的空气,以及土壤和水域中存在的各种无机营养物质,是生命活动的基本条件(即生态条件),各种各类的动植物群系是生命活动的主体;不同的陆地和水域则是生命活动的场所。作为主体的动植物群系的生长和繁衍,在很大程度上受着生态条件和生活场所的制约;反过来,动植物 I. An Important Problem in the Study of Tillage System From its own practice of agricultural production, human beings have come to realize that nature is a complicated and organic ecosystem. In this ecosystem, sunlight and radiant heat, moisture, air containing carbon dioxide, nitrogen and oxygen, and various inorganic nutrients present in soil and water are the basic conditions (ie, ecological conditions) of life activity, The flora and fauna of the genus are the main body of life activity; different land and waters are the places of life activity. The growth and reproduction of the flora and fauna as the main body are largely conditioned by ecological conditions and places of living; in turn, flora and fauna