Emergy unsustainability index for agricultural systems assessment: A proposal based on the laws of thermodynamics

Dependence on the socio-economic system impairs the sustainability of pasture-based animal agriculture

Livestock systems contribution to environmental change is controversial. Pasture-based systems are considered a sustainable alternative due to their adaptation to the use of local natural resources. However, they have limited productivity per product unit and, in Europe, depend on public economic support. Furthermore, they are heterogeneous in farm structure and resources use, which may determine their sustainability. We use emergy accounting to assess the sustainability of mountain pasture-based cattle systems and analyse the variability among farms. Emergy accounting assesses the sustainability performance of complex systems (i.e., farming systems) and their interaction with other systems (i.e., the environment and the socio-economic system) focusing on the origin, quality and quantity of the energy required for the system to function. Results show that pasture-based systems largely use local natural renewable resources but depend largely on the wider socio-economic system given their reliance on public economic support and purchased animal feeds. This economic dependence turns out in most farms largely using non-renewable resources. Increasing self-produced feeds and grazing on natural pastures can reduce the dependence on the socio-economic system and improve farm sustainability.

Rhizosphere engineering for sustainable crop production: entropy-based insights

There is a growing interest in exploring interactions at root-soil interface in natural and agricultural ecosystems, but an entropy-based understanding of these dynamic rhizosphere processes is lacking. We have developed a new conceptual model of rhizosphere regulation by localized nutrient supply using thermodynamic entropy. Increased nutrient-use efficiency is achieved by rhizosphere management based on self-organization and minimized entropy via equilibrium attractors comprising (i) optimized root strategies for nutrient acquisition and (ii) improved information exchange related to root-soil-microbe interactions. The cascading effects through different hierarchical levels amplify the underlying processes in plant-soil system. We propose a strategy for manipulating rhizosphere dynamics and improving nutrient-use efficiency by localized nutrient supply with minimization of entropy to underpin sustainable food/feed/fiber production.

Research on the sustainable development of agricultural product supply chain in three northeast provinces in China

Background

The sustainable development of the agricultural product supply chain (APSC) is the key to protecting public health.

Methods

This paper explores the sustainable development status of the APSC in three northeast provinces of China from 2007 to 2020 and the development trend in the next 5 years by using the entropy weight-matter-element extension model (MEEM) and autoregressive integrated moving average model (ARIMA), taking into account the background of relatively backward development and the high proportion of agricultural output in these three provinces.

Results

According to the research results, the sustainable development of the APSC in Jilin Province is relatively stable, Heilongjiang Province has made considerable progress in the sustainable development of the APSC in recent years, while Liaoning Province has shown a significant downward trend in recent years in the sustainable development of the APSC, despite a strong development momentum in previous years.

Conclusions

The findings of this paper can be applied to the governance of APSC in other rural areas with uneven development. The assessment also provides guidance on the quality and safety of agricultural products and public health, and raises the awareness of policymakers on the importance of the APSC.

Food Consumption Characteristics and Influencing Factors in a Grassland Transect of Inner Mongolia Based on the Emergy Method

Food consumption is the vital connection between human beings and natural resources. Our research explores the characteristics and drivers of food consumption patterns within Mongolian grasslands with a vulnerable ecology and environment. Food consumption data were obtained via a household questionnaire survey, and the emergy method was applied to analyze the food consumption characteristics in different grassland areas. This led to the following results: (1) The total per capita food consumption in different banners showed greater consumption and higher percentage of animal-based food in regions farther north. (2) From south to north, the main meat consumption in different banners varied, the predominant meat type consumed in Taibus was pork, that in Zhenglan was mutton, and that in West Ujimqin was beef. The farther north, the more fruits and vegetables were consumed. (3) The characteristics of food consumption in different areas were influenced by a series of factors, including social, economic, and ecological ones. Local food supply and disposable income were the main factors that had important effects on food consumption structure, as these two factors provided accessibility to foods for consumption.

Carbon footprint analysis of straw collection, transportation, and storage system for power generation in China based on emergy evaluation

Carbon footprint analysis method was employed to evaluate the ecological benefits of the straw collection, transportation, and storage system based on the case of Laifa Straw Recycling Company, and the emergy-based carbon emission indicator system was also set up to assess the relationship between input resource and carbon emission. In the condition of collecting 2 × 10⁸ kg of straw production, the carbon emission of the artificial model (7.26 × 10³ t CO_2eq) and mechanical model (6.11 × 10³ t CO_2eq) was greatly lower than that of the straw burned in the field (2.78 × 10⁵ t CO_2eq). According to the emergy-based carbon emission indicator system, the carbon emission of straw recycling system was mainly triggered from labor input, which could be reduced by adjusting the resource structure. The ratio of carbon emission to environmental loading rate (ELR_CO2) and ratio of carbon emission to emergy sustainability index (ESI_CO2) of the artificial model were 90.75E+6 kgCO_2eq and 1.52E+6 kgCO_2eq, respectively, which were higher than that of the mechanical model, 55.55E+6 kgCO_2eq and 1.22E+6 kgCO_2eq. It was obviously that the mechanical model had weaker influence on environmental loading than that of the artificial model and presented promising sustainable development ability in the case of mitigating carbon emissions.

Making Waves: A sea change in treating wastewater - Why thermodynamics supports resource recovery and recycling

Entropy is a concept defined by the second law of thermodynamics. Applying this concept to the world we live in, entropy production must be minimized and negentropy (negative entropy production) should be accelerated, in order to produce a healthy and stable ecological system. The present wastewater treatment, however, contributes to entropy production. This means that conventional wastewater treatment, without recovery of resource and energy, will gradually but inevitably contribute to a deteriorating ecological balance. When the self-cleaning ability of the natural ecological system is limited, the need to develop sustainable wastewater treatment in order to delay entropy production and accelerate negentropy becomes urgent. Resource and energy recovery from wastewater should be the first priority, as they can contribute significantly towards minimizing entropy production and accelerating negentropy. Sustainable wastewater treatment must focus on recovering recyclable high value-added organic chemicals from wastewater and/or excess sludge to minimize entropy production caused by methane (CH₄, once combusted, is converted into CO₂ - an even higher substance in entropy) via anaerobic digestion. Instead of CH₄, thermal energy present in the effluent can be utilized for heating/cooling buildings and also for drying excess sludge towards incineration to recover more energy. Overall, this can lead to a carbon-neutral operation and even creating a "carbon sink" could be possible for wastewater treatment.

Study on the Choice of Wastewater Treatment Process Based on the Emergy Theory

With the increase in industrialization and urbanization, water pollution has become increasingly serious, and wastewater treatment has become a common step in preventing this. For a greater understanding of the sustainability of different wastewater treatment systems, two processes, Anaerobic Baffled Reactor + Anaerobic-Anoxic-Oxic and Anaerobic Baffled Reactor + Cyclic Activated Sludge System, were selected, and their sustainability was evaluated based on three indicators, namely emergy yield ratio, environmental load rate, and emergy sustainability development index, according to emergy theory. The results show that the emergy yield ratio and environmental load rate of the ABR + CASS process were lower than those of the ABR + A2/O process, and the emergy sustainability development index of the ABR + CASS process was higher than that of the ABR + A2/O process, showing better sustainability. The research methods and findings of this study play an important role for decision makers in selecting sustainable wastewater treatment processes.

Regulatory Elements on the Circular Economy: Driving into the Agri-Food System

In the transition from linear production systems, unsustainable from the point of view of resources, to a model that finds strength in environmental, social and economic sustainability, the circular economy paradigm is the foundation that facilitates the planetary agro-ecological transition. The European Union has taken a number of steps (including the Circular Economy Package of Directives) shaping circularity as a wide-ranging driver measure involving many sectors. The paper intends to provide a regulatory framework on the current general situation regarding circularity in European Union, in order to extrapolate and give evidence to the aspects that intersect the agri-food sector. This is not only because they are poorly addressed in the literature, but also because there is a lack of regulatory instruments on the circular economy specifically addressing this area of interest. For this purpose, the analysis focuses on waste and residue/scrap management issues, recognized by law as by-products and end-of-waste status, as they are covered by circular economy legislation and as they can be applied to the agri-food sector. The latter allow the implementation of circularity strategies in the agri-food sector and, given the numerousness of production chains and the peculiarities of each of them, various regeneration and/or reuse processes of specific resources may be depicted. The intent is to provide useful knowledge on how to implement sustainable waste management, also proposing a concrete case on a by-product of olive oil processing, through which it is possible to highlight how the correct application of regulations favors the adoption of circular economic and management models in the firms involved, as well as informing the relevant economic operators on the possible profiles of legal liability that may arise from insufficient knowledge. Furthermore, this paper delves into the European Green Deal’s Strategy as it enriches the circular economy paradigm with new facets. NextGenerationEU and the National Recovery and Resilience Plan financially support this strategy in the aftermath of the socioeconomic crisis from COVID-19 in the EU Member States. This is in order to achieve the objective of achieving the agro-ecological transition.

Analysis of Food Production and Consumption Based on the Emergy Method in Kazakhstan

The imbalance in the supply and demand for resources is a thorny issue that many countries have to face. Food is a basic resource throughout the world. Understanding the exact situation of food production and consumption is an important foundation for sustainable development. This paper aims to explore the quantity and pattern changes in food production and consumption in Kazakhstan. This can reflect the level of residents' standard of living and the situation of natural resource use. This paper focuses on the quantitative relationship between animal-based food and plant-based food and the tendency towards changes in urban and rural residents' food production and consumption in Kazakhstan based on the emergy analysis method. The data of food production and consumption were mainly obtained from the official statistics of the Food and Agriculture Organization (FAO), the World Bank, Statistical Commission of the Ministry of National Economy of Kazakhstan, and literature. The research results showed that, over time, Kazakhstan residents' food consumption patterns have become more varied, and the proportion of meat consumption to total food consumption has increased. Although the rural per capita food consumption is significantly different from that of urban residents, this gap decreased in 2019. In Kazakhstan, the consumption of several types of food still relies on imports. Food production and consumption are affected by economic, social, and ecological factors. The results of this research can provide scientific support for reasonable and sustainable production and consumption strategies in Kazakhstan.