Cycle economic development evaluation of agricultural park based on emergy analysis

Circular agricultural park is a new organizational form of agricultural intensive production and enterprise management. It is also a cut-in point for the close combination of agricultural science and technology with rural economy and an important carrier for the transformation of high-tech achievements into real productive forces. In order to promote the reduction of resource consumption and pollution reduction in the circular agricultural park, realize the new requirements of agricultural modernization, with the development of agricultural supply side as the main line, the green development as the guide, and the institutional reform and mechanism innovation as the driving force. "Reduce", "Reuse" and "Recycle" are the core agricultural recycling economy. Based on the field research, the emergy value analysis is used to analyze and calculate the ecological flow in the agricultural recycling park system, and to reduce non-renewable resource consumption and reduce pollution. In order to maximize the economic benefits, the discharge pressure is the goal of building the circular economy system emergy value evaluation index system. Taking an agricultural science and technology park in the northwest as an example, the demand for various resources in the ecosystem of the park and the pressure of the discharged waste on the system are analyzed. The aim is to evaluate the sustainability of the park's circular economy development and make relevant development proposals. The results show that the primary industry in the park is dominant, and the economic development is highly dependent on the external raw materials and energy. The output emergy value is 42.05% of the total input emergy value, the emergy per-person value (EPP) is 5.04×1016 sej/person, emergy per-area (EPA) is 6.96×1012 m2. The overall economic development is better, but the development of the secondary and tertiary industries is weak; the park's emergy investment ratio (EIR) ) is 8.06, the emergy yield ratio (EYR) is 1.12, and the emergy reuse rate (ERR) is 29.27%. The resource utilization shows high external dependence, the overall resource reuse degree is low, and the use of its own resources. There is still much room for improvement in production efficiency; the emergy loading ratio (ELR) of the park is 8.11, the emergy waste ratio (EWR) is 11.57%, the waste utilization ratio (WUR) is 69.61%, the pressure of production activities on the environment is at a moderate level, and there is a certain waste recycling industry, but the overall utilization is limited; the emergy sustainable index (ESI) is 1.61, the sustainable development index (SDI) is 3.42, and the urban eco-efficiency index (UEI) is 0.88. The economic system is simple in level, the industrial structure is relatively simple, and there are still some shortcomings in self-organization ability, development potential and recycling capacity. The sustainable development performance needs to be improved. The industrial structure is relatively simple and is not balanced, and the utilization and resource efficiency of existing industries is low, which limits the further development of the park. It is recommended that the park further develops internal resources, improves resource utilization, increases system strength, adjusts the industrial structure of the park, coordinates industrial development, and enhances production efficiency. This is also useful for the evaluation of the development of circular economy in other agricultural parks in China.