Research Trends in Crop–Livestock Systems: A Bibliometric Review

Abstract

Agricultural straw waste and livestock manure are often misplaced resources. The separation of planting and breeding has induced significant pressure on the environment. Thus, there is a growing need for a system that can integrate crop and livestock farming to improve resource efficiency. To clarify the current state of crop–livestock systems in China and elsewhere, a bibliometric analysis was conducted for a total of 18,628 published English and 3460 published Chinese research articles and dissertations on circular agriculture. The published research papers were taken from the ISI Web of Science and CNKI database to explore research hotpots, research methods, theme trends, and mainstream technical models of crop–livestock systems from 1981 to 2021. Recent progress in crop–livestock systems was analyzed from ecological, economic, social benefits, and stakeholder perspectives. The research results showed that compared with traditional agricultural models, crop–livestock systems had far more ecologic and social benefits, including gaining higher net income and input-output ratio, improving soil quality, and mitigating global warming. The drivers of crop–livestock systems’ development were also analyzed from stakeholders’ perspectives. The study provides insights into the development of circular agriculture by reducing the pollution risks of agricultural waste and improving both ecological and economic benefits of the system.

Insights into Circular Horticulture: Knowledge Diffusion, Resource Circulation, One Health Approach, and Greenhouse Technologies

“…Europe markedly leads the dissemination of circular horticulture knowledge in terms of the most prominent countries, institutions, and authors. These results agree with a recent bibliometric mapping, where Italy, Spain, and China stand out in scientific production on circular agriculture, while the United States, China, and Germany are pioneers in crop-livestock systems research, with a strong circular influence [10,30]. Moreover, the geographical centralization of the circular economy worldwide has been found with certainty in Europe in most economic sectors, such as agriculture and horticulture.…”

Population structure of Phanaeus vindex (Coleoptera: Scarabaeidae) in SE Michigan

“…What makes this case study on the populations of the iconic rainbow scarab in SE Michigan even more relevant is that the same land use practices that threaten the populations of this species are threatening the populations of many other species and reduce biodiversity and the efficiency of ecosystem services in many rural areas of the United States and world-wide. Integrating farm animals on crop fields or on adjacent paddocked pastures (Integrated Crop-Livestock Systems, land-sharing) within a small-patch diverse landscape mosaic increases soil fertility ( Rakkar and Blanco-Canqui 2018 , Sartor et al 2019 , Galindo et al 2020 ) and may reduce greenhouse gas emissions relative to concentrated beef and dairy operation ( Ghahramani and Bowran 2018 , Yang et al 2022 ). Small cattle herders contributing to such systems should be supported as land stewards and receive supplementary funding similar to the USDA Conservation Reserve Program (CRP) for growing prairie strips ( Riffell et al 2008 , McMinn-Sauder et al 2020 , USDA Farm Service Agency 2020 ).…”

Integration of livestock in intercropping systems

“…In the scientific literature, a variety of roles for the crops and livestock in a production system are described, that provide insight into how crops and livestock may be complementary in a production system and improve nutrient cycles. Crops can provide feed for livestock (Yang et al, 2022) at an extremely low cost as most of the production costs are accounted for in crop production (Wright et al, 2012), and in this way residues, byproducts and grazed biomass that are not suitable for human consumption can be converted into animal products for human consumption (Schut et al, 2021). Furthermore, crops and trees can aid in the sequestration of carbon, hereby reducing the net emissions from livestock (Lal, 2020), and can provide a source of shade and shelter for livestock (Pieri & Gething (1992) in Lal (2020)).…”

“…Furthermore, crops and trees can aid in the sequestration of carbon, hereby reducing the net emissions from livestock (Lal, 2020), and can provide a source of shade and shelter for livestock (Pieri & Gething (1992) in Lal (2020)). On the other hand, livestock can provide manure to the crops (Yang et al, 2022), hereby reducing the need for external fertilizer input (Lal, 2020). Furthermore, the manure can be used as fuel or as building material (Wright et al, 2012).…”

“…Animals in integrated crop-livestock systems can recycle nutrients from the forage and feed to their excreta, which can subsequently be used to fertilize the soil (Hilimire, 2011). Through returning crop-livestock manure to the field, the physical properties and nutrients of the soil change (see Table 1 (adapted from Hilimire, 2011); Yang et al, 2022). For example, increases in soil porosity, soil organic matter, soil-available phosphorus and soil-available potassium may result, improving overall soil quality (Yang et al, 2022).…”