Efficient agricultural water research under elevated global carbon dioxide concentration – Based on bibliometric analysis

Freshwater resources are scarce globally, and the increase in carbon dioxide (CO2) concentration leads to both a decrease in soil moisture and arid climate, further limiting agricultural production. Therefore, it is critical to achieve water efficiency in agriculture under elevated CO2 concentration. A comprehensive analysis was conducted on the research topic of efficient agricultural water under elevated CO2 concentration using bibliometric methods. The results show that the number of papers on this research has changed from an accumulation phase (1992–2005, 395) to a growth phase (2006–2023, 963). "Carbon dioxide", "water-stress", "growth", "photosynthesis", "yield", and other keywords have been the focus of past research in this area. Kimball BA and Ainsworth EA are the most influential authors in this area. Leakey's (2009) paper in “Experimental Botany” was the most contributing study, summarizing six lessons about the effects of CO2 enrichment on the relationship among carbon, nitrogen, and water in plants. The United States and China were the most influential countries. Over time, research has shifted from an early focus on atmospheric CO2 change itself to the response of crops to elevated CO2 in agricultural production. The efficient crop production strategy under the interaction of environmental factors is becoming a hot spot for future research, and the emission and use of greenhouse gases, the improvement of crop quality, and the efficient guidance of models are also worth exploring. Overall, this study presents a quantitative analysis and comprehensive review of past research conducted on the effect of water and fertilizer on agricultural production under CO2 enrichment. It also offers suggestions and expectations for future research on the hot spot direction of efficient crop production under climate change.