The circular agricultural system is more sustainable: emergy analysis

The agricultural sector contributes 18% of global greenhouse gas (GHG) emissions. For the agricultural sector, most countries have pledged to reduce emissions by around 50% relative to emissions in 1990. One of the paths of achieving this goal is practicing a circular agriculture system that integrates livestock and farming. The present study evaluates and compares the sustainability of an agricultural system progressively transitioning from linearity to circularity. The study's objective is to verify the hypothesis that a circular agricultural system has a good self-organizing capacity, minimizes non-renewable purchased inputs, causes minimum stress to the environment, and maximizes economic and social benefits compared to the agricultural system in standalone. To analyze the environmental effect of the agricultural system, the present study uses emergy analysis and evaluation of avoided impact due to recycling of waste from livestock and farming. A case study of three farming systems is used for the assessment in the present work. The linear agricultural system (AS-P), the agricultural system with livestock (AS-L), and the circular agricultural system that integrate livestock and feedback (AS-IFL). The circular agricultural system was shown to have significant recycling advantages, with 3.29 E + 17 solar emergy joules (sej)/year saved emergy and 2.51E + 06 kg avoided carbon dioxide emissions per hectare per year. The resources saved as a result of the system's great recycling potential make it even more cost-effective. Fodder accounted for a significant portion of the purchased input, which might be decreased by in-house cultivation or the utilization of farm-generated agro wastes. The current study supports the concept that crop and animal farming are complementary and lead to a sustainable agricultural system in which one system's waste is used as a resource for the other. Out of the three human basic needs (food, clothing, and shelter), two are related to agriculture. Therefore, sustainable agriculture is in the interest of humanity's wellbeing as it is a major subsystem of plant earth.