The process for reasonably evaluating the potential impacts of circular agriculture on the environment has become a key issue in the sustainable development of circular agriculture. Based on this consideration, by using Life Cycle Assessment (LCA) and focusing on the circular agriculture industry company of Xingyuan, Fuqing, this paper evaluates the potential impacts of the pig farming industry-dragon fruit planting-forage planting-fishery industry-mushroom planting-biogas generating-organic fertilizer production circular agriculture model compared to a main agriculture industrial model, the pig farming industry, from environmental and environmental-economic perspectives. Moreover, this paper determines key elements that restrict the development of circular agriculture through a sensitivity analysis. The results show that if we simply consider the potential environmental impacts, circular agriculture does not produce better results than those of the main agricultural production model. In addition, if we consider reducing the potential environmental impact as well as improving the economic benefits from the perspective of a “reduction ring”, we should consider removing mushroom planting and organic fertilizer from the circular agriculture framework. Moreover, if we want to reduce the potential environmental impact without changing the current recycling model, we should focus on the premix components, especially the three main components of corn, soybean meal, and whey protein concentrate.

Swine wastewater contains large amounts of organic matter, nutrients, toxic metal elements, and antibiotics. If it is directly discharged or not properly treated, it poses a significant threat to the environment and human health. Currently, the management of swine wastewater has become a focus of social attention, and it adopts a dual-track parallel model of standard discharge supplemented by resource utilization. If treated properly, it can achieve the recycling of water resources and promote the effective recovery of resources. Based on the pollution characteristics of swine wastewater, this paper analyzes its impact on the environment, society, and the economy in detail and expounds on the research progress of swine wastewater treatment technology. From the perspective of resource utilization and recycling of anaerobic digestion liquid (biogas slurry) from swine wastewater and the carrying capacity of the soil environment and cumulative ecological environmental risks, this study explores new development trends and application prospects for swine wastewater treatment technology.

This study aimed to determine the microbial diversity of different soil depths (0-5 and 5-20 cm) in a subtropical orchard during different seasons (i.e., Spring, Summer and Autumn) for enrich the knowledgements on micorbes roles in orchard ecosystem balance. In tracking experiments conducted in an orchard (established in 1996), the phospholipid fatty acid (PLFA) biomarker method was employed to know soil microbial system. Total PLFAs concentration did not vary significantly between soil depths but changed between seasons. It peaked in the summer at 258.97 ± 23.48 μg g ^-1 soil from 0-5 cm and at 270.99 ± 58.94 μg g ^-1 soil from 5-20 cm. A total of 33 microbial fatty acid biomarkers were observed and identified in the sampled soil. Quantities of PLFAs for 29 microbe groups varied significantly between seasons, except for 15:0 iso 3OH, 15:1 iso G, 16:0 2OH, and 17:0 iso 3OH. The bacterial PLFAs and fungal and actinomycotic PLFAs in the orchard soil collected in Summer were significantly higher than in the Spring or Autumn ( P < 0.01). The number of soil microorganism species (Richness) and the Simpson and Shannon-Wiener indexes were all the highest in summer. The total PLFAs, bacterial PLFAs, fungal PLFAs, actinomycotic PLFAs, Richness, or the Simpson and Shannon-Wiener indexes were all significantly negatively correlated with soil pH, total carbon (TOC), total nitrogen (TN) and cation-exchange capacity (CEC) ( P < 0.05).