Characteristics of agricultural system at different development stages in Northeastern China

Agriculture, as the foundation of the national economy, has its strong internal organic system as well as its relevance with the external world. Therefore, it is of great significance to analyze evolution of agricultural system from a historical perspective in a macroscopic view and to objectively judge the reasonableness of the structural change of agricultural system and its functional evolvement. The paper explored that development of agricultural systems experienced four stages in the Northeast of China historically, which were: 1) the differentiation stage between the hunting and fishing system and the acquisition system; 2) the differentiation stage between the agricultural and pastoral system and the fishing and hunting; 3) the longterm complementary coexistence phase of agriculture, animal husbandry, fishing and hunting; and 4) the differentiation stage of the farming system and the livestock system. At each stage, organizational form and function of the agricultural system structure were different; and the system development trend was the structure plurality and function stability. Finally, the paper summarized factors of promoting evolution of the agricultural system in Northeastern of China, which included ecological constraints and climate disturbance; war famine and pastoral policies; migration and economic exchange; cultural radiation and technological diffusion; religion and dietary customs; and transportation conditions and market exchange etc.