China's agricultural civilization has lasted for thousands of years, and the wisdom of combining farming and breeding has always run through it. From the ecological cycle of "mulberry fish pond" to the low-carbon transformation of modern agriculture, this model is not only the essence of Chinese farming civilization, but also revitalized under the contemporary goal of rural revitalization and carbon neutrality. This article will review the historical context of the combination of farming and breeding in China, explore its policy objectives, institutional evolution and opportunities of The Times, and look at how low-carbon technologies can inject new momentum into this traditional model.

In ancient China, the core of agriculture was "farming, reading and passing down the family", and the combination of planting and breeding was the key to maintain ecological balance. Farmers take the family as a unit, planting grain and raising poultry are closely combined: crop straw is fed to livestock, and livestock manure is returned to the field to fertilize the soil, forming a closed-loop cycle. This pattern is recorded in Qimin Yaoshu and the Complete Book of Agricultural Administration, which reflects the simple ecological view of "taking from the soil and returning to the soil".

Policies and institutions: Successive dynasties consolidated the foundation of agriculture through the policy of "emphasizing agriculture and suppressing commerce", such as the "substitute field method" of the Han Dynasty and the "green seedling method" of the Song Dynasty, which all implied the concept of resource recycling. However, limited by the scale of smallholder economy, the combination of farming and breeding has always been based on the family, and there is a lack of systematic system design.

After the founding of New China, in order to increase grain production, agriculture turned to industrial production. Although the popularity of fertilizers and pesticides has improved the production capacity in the short term, it has led to the separation of breeding and breeding: the large-scale expansion of farms and the direct discharge of feces and sewage; The farming industry relies on chemical fertilizers, and soil degradation is a major problem.

Change in policy objectives: In the 1980s, environmental issues entered the policy vision. Environmental Protection Law for the first time put forward agricultural pollution prevention requirements; In the 1990s, the strategy of "sustainable development" promoted the combination of planting and breeding to return to the discussion, but it was limited by technical shortcomings and economic priority orientation, and the practical effect was limited.

After the founding of New China, in order to increase grain production, agriculture turned to industrial production. Although the popularity of fertilizers and pesticides has improved the production capacity in the short term, it has led to the separation of breeding and breeding: the large-scale expansion of farms and the direct discharge of feces and sewage; The farming industry relies on chemical fertilizers, and soil degradation is a major problem.

Change in policy objectives: In the 1980s, environmental issues entered the policy vision. Environmental Protection Law for the first time put forward agricultural pollution prevention requirements; In the 1990s, the strategy of "sustainable development" promoted the combination of planting and breeding to return to the discussion, but it was limited by technical shortcomings and economic priority orientation, and the practical effect was limited.

System innovation:

In 2017, the Action Plan for the resource utilization of livestock and poultry breeding Waste clarified the regional collaborative mechanism of "breeding by species and promoting species by cultivation"; In 2021, the "14th Five-Year Plan" for the Development of circular economy will focus on the combination of planting and breeding, and support initiatives such as biogas projects and organic fertilizers instead of fertilizers; At the same time, the pilot carbon trading market will include agricultural emission reduction in accounting to stimulate green technology innovation.

Technology enabling industry chain:

Driven by policies, enterprises represented by Qingdao Zhonghai Environmental Engineering Co., Ltd. promote the integration and upgrading of planting and breeding through low-carbon technologies of the whole industrial chain:

• Front-end treatment: Provide advanced treatment equipment, efficient treatment of livestock and poultry manure, lay a good foundation for the subsequent links, and effectively reduce the generation of pollutants.

• Compost fermentation: The use of compost film fermentation equipment to optimize the fermentation process, so that livestock manure is fully converted into organic fertilizer, improve the quality of fertilizer.

• Back-end processing: with organic fertilizer deep processing equipment, fine processing of the products after fermentation, to produce more in line with market demand and crop growth needs of high-quality organic fertilizer.

• Sewage treatment: Sewage treatment equipment can purify and treat the sewage generated in the breeding process, so that it can reach the discharge standard or the level of recycling, and reduce the pollution to the environment.

• Biogas equipment: The supporting biogas equipment efficiently collects and uses the biogas generated in the fermentation process, converts it into clean energy, realizes the recycling of energy and reduces carbon emissions.

• End efficiency enhancement: The use of digital platform to achieve the matching of planting and breeding main resources, and promote the construction of regional energy and nutrient circulation network.

Although the combination of planting and breeding has become a policy consensus, problems such as imperfect land transfer mechanism, high cost of technology application for small and medium-sized farmers, and insufficient cross-departmental coordination still need to be broken through. In the future, we need to make efforts in three aspects:

• Policy integration: break through the policy barriers in the fields of agriculture, environmental protection and energy, and establish the incentive mechanism of "carbon-nitrogen collaborative emission reduction";

• Technology inclusive: promote modular, low-cost processing equipment, so that small and medium-sized farmers "affordable, good use";

• Market activation: Guide social capital to participate in circular agriculture through green finance and ecological compensation mechanisms.

In this process, the whole industrial chain service providers with low-carbon technology as the core are becoming an important link between policy and market. Through technology output and model innovation, enterprises can help local governments build a "one county, one policy" breeding cycle plan to achieve a win-win situation of ecological benefits and economic benefits.

From "relying on the sky to eat" to "going green", the evolution of China's combination of breeding and breeding is a harmonious history of the relationship between man and nature. Under the goal of carbon neutrality, this traditional model is writing a new chapter in the green transformation of agriculture with the help of institutional innovation and technological breakthroughs. How to integrate low-carbon technology into the field and make the millennium farming wisdom glow with modern vitality will be the common mission of the entire industry.