Investigation and development analysis of planting-breeding circulating agriculture ecosystem system in northern plains in China

Abstract: Recycle agriculture is an efficient utilization and resource-saving mode of agriculture, and an inevitable choice for modern agriculture to step out of developmental dilemma. It has been the effective way to realize sustainable utilization of agricultural resources and cleaner agricultural production. China has already had a history of circular agriculture, and in recent years, circular agriculture and resource utilization of agricultural residues are getting more and more attentions. Based on regional natural conditions, industry types, resources endowment, and so on, various models of planting-breeding circulating agriculture ecosystems are formed in China. Due to the production strength and high intensive degree of farming and breeding in northern plains (containing northeast, northwest and Huang-Huai-Hai region), planting and breeding produce a large amount of waste, and long-term separation of planting and breeding industry causes the inefficient resources use, which has brought serious regional environmental hazards. Development of the planting-breeding circulating agriculture is very necessary and urgent. There was lack of systematic research on the models of planting-breeding circulating agriculture in northern plains, and the summarization of problems is needed. In this article, the resource utilization engineering for agricultural residues containing biogas engineering, organic fertilizer plant, and feed mill from 121 counties with large-scale planting-breeding industry in northern plains, was systematically investigated and analyzed through investigation and literature analysis. Among the 121 counties, there are 32 in northeast area, 19 in northwest area and 70 in Huang-Huai-Hai region. The research contents mainly include the production and utilization status, and the ways of use for straw, and livestock and poultry manure, other planting and breeding industries, and so on. The results showed that based on the resource utilization for agricultural residues (such as livestock and poultry manure, straw, and vegetable wastes), there are biogas engineering-linked, aerobic composting-linked, and straw resource utilization-linked planting-breeding circulating agriculture ecosystems which have been developed in northern plains in China. In the biogas engineering-linked system, cultivation of crops, production of livestock and poultry, fermentation of microorganisms and construction of rural areas, are rationally combined with biogas projects as a link, and it includes large scale biological gas engineering and biogas engineering-linked, and middle and small size and household biogas-linked circulating agriculture ecosystems. In the aerobic composting-linked agriculture ecosystems, high temperature aerobic composting is a link to deal with agricultural wastes such as crop straw and livestock manure, and some companies use this method to produce commercial organic fertilizer. In the northern plain of China, straw resources are abundant, and the resource utilization of straw is combined with other agricultural production methods to form straw utilization-linked recycling agricultural models, such as feed utilization and utilization of crop straw in soilless culture. Combined with the actual agricultural production in China, the in-depth analysis on the deficiencies and problems of existing planting-breeding circulating agriculture ecosystems was also conducted. The balance of planting and breeding, the mode selection and the key technology should be researched and improved in planting-breeding circulating agriculture ecosystems, to guide the development of planting-breeding circulating agriculture in northern plains and even in China.