The challenge of transitioning from a linear to a circular economy model is still ongoing and requires the development and application of new knowledge, leading to innovative, technological, and sustainable processes, products, and services. The evolution of global research on this topic from 2004 to 2019 was studied in this work. For this purpose, a bibliometric analysis of 1366 articles was applied, producing results on the scientific productivity of the driving agents that most contribute to this theme. The findings show a growing interest, especially in the last four years, in the study of circular economy (CE) policies on the environment. The main subject area that articles address is environmental science. Five research lines have been identified, which mainly study the efficient management of energy resources and the economic factors that make the CE model possible: Environmental pollution and agricultural activity; waste management to avoid a negative environmental impact; improvement of the environmental impact through ecological products; the product life cycle, and the consequences of climate change. The implementation of CE policies will contribute to making economies less dependent and unprotected and more competitive. Global research has exhibited an upward trend during the period analyzed and has grown exponentially since 2015, coinciding with the publication of the Sustainable Development Goals (SDGs) of the 2030 Agenda.

Irrigated agriculture plays a fundamental role as a supplier of food and raw materials. However, it is also the world’s largest water user. In recent years, there has been an increase in the number of studies analyzing agricultural irrigation from the perspective of sustainability with a focus on its environmental, economic, and social impacts. This study seeks to analyze the dynamics of global research in sustainable irrigation in agriculture between 1999 and 2018, including the main agents promoting it and the topics that have received the most attention. To do this, a review and a bibliometric analysis were carried out on a sample of 713 articles. The results show that sustainability is a line of study that is becoming increasingly more prominent within research in irrigation. The study also reveals the existence of substantial differences and preferred topics in the research undertaken by different countries. The priority issues addressed in the research were climatic change, environmental impact, and natural resources conservation; unconventional water resources; irrigation technology and innovation; and water use efficiency. Finally, the findings indicate a series of areas related to sustainable irrigation in agriculture in which research should be promoted.

Within a context of scarce water resources for agriculture, rainwater harvesting constitutes a promising alternative that has been studied by different disciplines in recent years. This article analyses the dynamics of global research on rainwater harvesting for agricultural irrigation over the last two decades. To do this, qualitative systematic analysis and quantitative bibliometric analysis have been carried out. The results reveal that this line of research is becoming increasingly important within research on irrigation. Environmental sciences and agricultural and biological sciences are the most relevant subject areas. Agricultural Water Management, Physics and Chemistry of the Earth, and Irrigation and Drainage are the journals that have published the most articles on the subject. India, China, the United States (USA), South Africa, and the Netherlands are the countries that lead this line of research. Although significant progress has been made in this subject area, it is necessary to increase the number of studies on the capacity of rainwater harvesting systems to cover irrigation needs in different farming contexts, the factors that determine their adoption by farmers, the economic and financial feasibility of their implementation, and their contribution to mitigating global climate change.

The joint application of bioeconomy (BE) and circular economy (CE) promotes the sustainable use of natural resources, since by applying a systemic approach, it improves the efficiency of these resources and reduces the impact on the environment. Both strategies, which belong to the area of green economy, provide a global and integrated approach towards environmental sustainability, as regards the extraction of biological materials, the protection of biodiversity and even the primary function of food production in agriculture. The objective was to analyze the implications for sustainability of BE and CE joint application. A systematic and bibliometric review has been applied to a sample of 1961 articles, selected from the period 2004–May 2021. A quantitative and qualitative advance is observed in this field of study. The expansion of scientific production is due to its multidisciplinary nature, since it implies technical, environmental and economic knowledge. The main contribution of this study is to understand the state of research on the implications for sustainability that BE and CE have when combined, in relation to their evolution, the scientific collaboration between the main driving agents, and the identification of the main lines of research developed.

In this current and global context led by scarcity of resources, environmental degradation, global climate change, and a progressive demand for food, the circular economy (CE) represents a key economic model or framework for sustainable, restorative, and regenerative agriculture. Hence, CE applied to agriculture seeks to close the life cycle of products, services, waste, water, and energy to obtain a better use of resources and a reduction of the ecological impact. An initial review of the literature corroborates the hypothesis that the CE framework has not yet been comprehensively adapted to the field of agriculture. This research seeks to overcome this gap in relation to the performance of the circularity of agricultural production systems in support of decision-making processes. A bibliometric analysis of 1060 documents was carried to synthesize the knowledge base on this topic. The results show recent studies that identify weaknesses derived from food production, such as waste generation, biomass, water pollution, and greenhouse gas emissions. It has been identified how their analysis has developed to date and what terms allow us to visualize new approaches; consequently, it is a useful tool for researchers and sponsors who provide financial resources for the development of new lines of research.

Circular economy (CE) and sustainability are interrelated, without being exchangeable. While sustainability tries to reconcile the management of productive resources with their increasing consumption, CE aims to make the productive process more efficient, reducing, reusing and recycling the results of the productive process as much as possible. The aim of this paper is to ascertain the systemic structure of interactions between sustainability and CE through the analysis of the existing literature from 2004 to 2021. For this purpose, a computational literature review and a content analysis of the main contributions of CE and sustainability, within the framework of the Sustainable Development Goals (SDGs), were conducted. The results show that there is a positive impact of the synergy between CE strategies and certain SDGs. Specifically, the circular strategies that generate the greatest synergies have to do with preserving materials through recycling, downcycling, and the measurement of indicators or reference scenarios. This is what has led to the inclusion of these concepts in the formulation of policies and strategies, as their multidisciplinary nature allows them to have an impact on areas such as agriculture or innovation, which currently lack specific measures. Therefore, the knowledge derived from this study will contribute favorably to future decisions and actions to be considered, as there is still the potential to legislate in favor of an even more sustainable framework.